CHAPTER – 3 The Delhi Sultans | CLASS 7TH | NCERT HISTORY IMPORTANT QUESTIONS & MCQS | EDUGROWN

Chapter - 3 The Delhi Sultans

MCQs

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CHAPTER – 2 New Kings and Kingdoms | CLASS 7TH | NCERT HISTORY IMPORTANT QUESTIONS & MCQS | EDUGROWN

Chapter - 2 New Kings and Kingdoms

MCQs

Question 1.
Which new dynasty developed in eastern part of the country?
(a) Cholas
(b) Palas
(c) Chahamanas
(d) Rashtrakutas

Answer

Answer: (b) Palas


Question 2.
What was the other name of the great lord of a ‘circle’ or region?
(a) Samantas
(b) Subordinates
(c) Maha-mandaleshvara
(d) King

Answer

Answer: (c) Maha-mandaleshvara


Question 3.
Who were expected to bring gifts for their kings in 17th century?
(a) Samantas
(b) Overlords
(c) Maha-samantas
(d) Maha-mandaleshvara

Answer

Answer: (a) Samantas


Question 4.
When were Samantas declared Maha-samantas?
(a) When they bring gifts for their kings
(b) When they provide kings with military support
(c) When they gain power and wealth
(d) None of the above

Answer

Answer: (c) When they gain power and wealth


Question 5.
What is the literal meaning of hiranya-garbha?
(a) Rashtrakutas
(b) Dantidurga
(c) Golden womb
(d) Golden deer

Answer

Answer: (c) Golden womb


Question 6.
From whom was the Revenue also collected?
(a) Traders
(b) Merchants
(c) Peasants
(d) Artisans

Answer

Answer: (a) Traders


Question 7.
What is Vetti?
(a) Rent
(b) Tax
(c) Revenue
(d) None of these

Answer

Answer: (b) Tax


Question 8.
What was the use of money collected from taxes?
(a) To finance the kings’ establishment
(b) Construction of temples and forts
(c) To fight wars
(d) All of these

Answer

Answer: (d) All of these


Question 9.
The functionaries for collecting revenue were recruited from
(a) peasants
(b) artisans
(c) traders
(d) influential families

Answer

Answer: (d) influential families


Question 10.
Prashastis tell us how rulers wanted to depict themselves as
(a) leader
(b) valiant victorious warriors
(c) achiever
(d) all of these

Answer

Answer: (b) valiant victorious warriors


Question 11.
In which language was the prashasti found in Gwalior written?
(a) Hindi
(b) English
(c) Sanskrit
(d) Urdu

Answer

Answer: (c) Sanskrit


Question 12.
Who was Nagabhata?
(a) Gupta ruler
(b) Chakrayudha
(c) Malava
(d) Pratihara king

Answer

Answer: (d) Pratihara king


Question 13.
Brahmanas were rewarded by grants of land recorded on
(a) copper plate
(b) iron plate
(c) silver plate
(d) none of these

Answer

Answer: (a) copper plate


Question 14.
The person who received the land could collect taxes on
(a) betel leaves
(b) woven clothes
(c) vehicles
(d) all of these

Answer

Answer: (d) all of these


Question 15.
Who invaded the Somnath temple in Gujarat?
(a) Akbar
(b) Muhammad Ghori
(c) Mahmud Ghazni
(d) None of them

Answer

Answer: (c) Mahmud Ghazni


Question 16.
Who ruled in Tamil Nadu?
(a) Cholas
(b) Chalukyas
(c) Rashtrakutas
(d) None of these

Answer

Answer: (a) Cholas


Question 17.
From Uraiyur to Thanjavur 5.1.1 Muttaraiyar held power in this delta region:
(a) Kaveri
(b) Krishna
(c) Mahanadi
(d) Godavari

Answer

Answer: (a) Kaveri

Question 1.
Which new dynasties emerged after the 7th century in subcontinent?
Answer:
Many new dynasties emerged after the 7th century like:

  • Guijara-Pratiharas
  • Rashtrakutas
  • Palas
  • Cholas
  • Chahamanas or Chauhan

The Emergence of New Dynasties

Question 1.
Who were samantas? What service did they provide to the existing kings?
Answer:

  • Samantas were big landlords or warrior-chiefs in different regions of the subcontinent.
  • Existing kings considered them as their subordinates.
  • Services Provided by the Samantas:
  • Samantas brought gifts for their kings or overlords.
  • They remained present at their courts or functions organized by them.
  • They provided them with military support.

Question 2.
What happened when Samantas gained power?
Answer:

  • When Samantas gained power and wealth, they declared themselves to be maka-samanta, maha-mandaleshvara (the great lord of a ‘circle’ or region).
  • Sometimes they asserted their independence from their overlords.
  • Examples:
  • In the mid-eighth century Dantidurga, a Rashtrakuta chief, overthrew his Chalukya overlord and performed a ritual called hiranya-garbha meaning the golden womb.

Question 3.
How did the Rashtrakutas gained power and independent?
Answer:
Rashtrakutas became powerful in the following manner:

  • Rashtrakutas were subordinates to the Chalukyas of Karnataka.
  • In the mid-eighth century Dantidurga, a Rashtrakuta chief, overthrew his Chalukyan overlord.
  • He performed a ritual called Hiranya-garbha with the help of Brahmanas.
  • This ritual was, then, considered to lead the rebirth of the sacrificer as Kshatriya, even if he was not Kshatriya by birth.

Question 4.
Give another example of samantas establishing their kihgdoms.
Answer:

  • Some other samantas from risk taking families used their military skills to
    carve out kingdoms.
  • Kadamba Mayurasharman and the Gurjara-Pratihara Harichandra were Brahmanas.
  • They gave up their traditional professions and took to arms.
  • They successfully established kingdoms in Karnataka and Rajasthan respectively.

Administration in the Kingdoms

Question 1.
What titles did the new kings adopt?
Answer:

  • Many of the new kings adopted high-sounding titles.
  • These titles were Maharaja-adhiraja meaning great king, Overlord of kings, Tribhuvana-chakravartin meaning lord of the three worlds and so on.
  • However, in spite of such claims, they often shared power with their samantas as well as with associations of peasants, traders and Brahmanas.

Question 2.
From where did resources come to these states?
Answer:

  • In each of these states, resources came from the producers like peasants, cattle- keepers and artisans.
  • They were often persuaded or compelled to surrender a part of their production.
  • Sometimes these were claimed as ‘rent’ due to a lord claiming his ownership of the land.
  • Revenue was also collected from traders.

Question 3.
What do inscriptions of the Cholas refer to as four hundred taxes?
Answer:

  • The inscriptions of the Cholas who ruled in Tamil Nadu refer to more than 400 terrhs for different kinds of taxes.
  • The most frequently mentioned tax is Vetti, taken not in cash but in the form of forced labour, and Kadamai, or land revenue.
  • Other taxes were also charged.
  • Taxes on thatching the houses.
  • The use of a ladder to climb palm trees.
  • A cess on succession to family property, etc.

Question 4.
How were resources used in the period 7th to 12th centuries?
Answer:
The resources were used in the following ways:

  • To finance the king’s establishment.
  • In the construction of temples and forts.
  • To fight wars, which were in turn expected to lead to the acquisition of wealth in the form of plunder.
  • To access to land as well as trade routes.

Question 5.
Who collected the revenue?
Answer:

  • The functionaries for collecting revenue were generally recruited from influential families.
  • Their positions were often hereditary.
  • This was true about the army as well.
  • In many cases, close relatives of the king held these positions.

Prashastis and Land Grants

Question 1.
What were prashastis?
Answer:

  • Prashastis were the certificates which contained details that might not be literally true.
  • They told how rulers wanted to depict themselves—as valiant, victorious warriors.
  • These were composed by learned Brahmanas, who occasionally helped in the administration.

Question 2.
How were Brahmanas rewarded?
Answer:
Kings often rewarded Brahmanas with grants of land.

  • These were recorded on copper plates.
  • The plates were given to those who received the land.

Question 3.
Describe the ‘achievements’ of Nagabhatta.
Answer:

  • Many rulers described their achievements in prashastis.
  • One prashasti; written in Sanskrit and found in Gwalior, Madhya Pradesh, describes the exploits of Nagabhatta, a Pratihara king.

It follows like this:

  • This king of Andhra, Saindhava {Sind), Vidarbha (part of Maharashtra) and Kalinga (part of Orissa) fell before him even as he was a prince.
  • He won a victory over Chakrayudha (the ruler of Kanauj). He defeated the king of Vanga (part of Bengal), Anarta (part of Gujarat), Malava (part of Madhya Pradesh), Kirata (forest people), Turushka (Turks), Vatsa, Matsya (both kingdoms in north India).

Question 4.
What was unusual about Kalhana’s writing?
Answer:

  • Unusual thing for the twelfth century was a long Sanskrit poem.
  • It contained the history of kings who ruled over Kashmir.
  • It was composed by an author named Kalhana.
  • He used a variety of sources. They included the following:
    1. Inscriptions
    2. Documents
    3. Eyewitness accounts
    4. Earlier histories.
  • Unlike the writers of prashastis, he was often critical about rulers and their policies.

Question 5.
What was given with the land?
Answer:
The following were given with the land:

  • Boundaries made of embankments and thorny bushes.
  • Fruit bearing trees
  • Gardens and orchards
  • Wells
  • Open spaces
  • Pasture lands
  • Platforms
  • Beehives
  • Ditches
  • Rivers
  • Silt laden lands
  • Granaries
  • Fish ponds
  • Deep lakes.

Question 6.
What were the rights of the people who received land grants during Chola rule?
Answer:
Those who received land grants could collect taxes from it in different forms.

  • As judicial fines.
  • On betel leaves, woven cloth and vehicles.
  • They could build buildings with baked bricks having upper stories.
  • Get wells dug and canals constructed.
  • Plant trees, thorny bushes.
  • Stop water wastage and build embankments.

Warfare for Wealth

Question 1.
How did new rulers gain power?
Answer:
All the ruling dynasties were based in a specific region.

  • At the same time, they tried to control other areas.
  • One particularly prized area was the city of Kanauj in the Ganga valley.
  • For centuries, rulers belonging to the Guijara-Pratihara, Rashtrakuta and Pala dynasties fought for control over Kanauj.
  • As there were three ‘parties’ in this long drawn conflict, historians often describe it as the “tripartite struggle”.
  • Rulers also tried to demonstrate their power and resources by building large temples.
  • When they attacked one another’s kingdoms; they often chose to target temples, which were sometimes extremely rich.

Question 2.
Who was Mahmud Ghazni? How did he expand his kingdom?
Answer:

  • One of the best known of such rulers is Sultan Mahmud of Ghazni, Afghanistan.
  • He ruled from 997 to 1030 A.D.
  • He extended control over parts of Central Asia, Iran and the north-western part of the subcontinent.
  • He Raided the subcontinent almost every year—his targets were wealthy temples including Somnath, Gujarat.
  • He used most of the wealth to create a splendid capital city at Ghazni.
  • He was interested in finding out more about the people he conquered.
  • He entrusted a scholar named al-Biruni to write an account of the subcontinent.
  • This Arabic work, known as the Kitab al-Hind, remains an important source for historians.
  • He consulted Sanskrit scholars to prepare this account.

Question 3.
Describe the other kings who engaged themselves in warfare.
Answer:

  • Other kings who engaged themselves in warfare were the Chahamanas.
  • They were later known as the Chauhans.
  • They ruled over the region around Delhi and Ajmer.
  • They attempted to expand their control to the west and the east, where they were opposed by the Chalukyas of Gujarat and the Gahadavalas of western Uttar Pradesh.
  • The best-known Chahamana ruler was Prithviraja III (1168-1192).
  • He defeated Afghan ruler named Sultan Muhammad Ghori in 1191.
  • He lost to him in the very next year, in 1192.

A Closer Look: the Cholas

From Uraiyur to Thanjavur

Question 1.
How did the Cholas rise to power?
Answer:

  • A minor chiefly family known as the Muttaraiyar held power in the Kaveri delta.
  • The family was subordinate to the Pallava kings of Kanchipuram.
  • Vijayalaya belonged to the ancient chiefly family of the Cholas from Uraiyur.
  • He captured the Kaveri delta from the Muttaraiyar in the middle of the ninth century.
  • He built the town of Thanjavur and a temple for goddess Nishumbhasudini there.
  • The successors of Vijayalaya conquered neighbouring regions.
  • Thus the kingdom grew in size and power.
  • They won the Pandyan and the Pallava territories to the south and north and made these areas part of this kingdom.
  • Rajaraja I was considered the most powerful Chola ruler.
  • He became king in 985 A.D. and expanded control over most of these areas.
  • He also reorganised the administration of the empire.

Question 2.
Who were the best remembered Chola kings? Which regions or areas were attacked by Rajendra I?
Answer:
The’two best remembered Chola rulers were Rajaraja I and his son and successor Rajendra I.
The great Chola ruler Rajendra I attacked the Ganga valley (North India), Sri Lanka ^ and some countries of South-East Asia, developing a powerful navy for these military expeditions.

Splendid Temples and Bronze Sculpture

Question 1.
Describe the splendid temples and the bronze sculptures of the Cholas.
Answer:
Splendid temples and bronze sculptures of the Cholas:

  • Rajaraja and Rajendra built big temples of Thanjavur and Gangaikondacholapuram.
  • They are architectural and sculptural marvels.
  • Chola temples often became the centre of settlements around them.
  • These were centres of craft production.
  • Temples were also endowed with land by both rulers and others.
  • The produce of this land went to maintain all the specialists who worked at the temple and very often lived near it.
  • They included priests, garland makers, cooks, sweepers, musicians, dancers, etc.
  • In other words, temples were not only places of worship; but also the hub of economic, social and cultural life.
  • Amongst the crafts associated with temples, the making of bronze images was the most important.
  • Chola bronze images are amongst the finest in the world.
  • Most images were of deities, sometimes images were made of devotees also.

Agriculture and Irrigation

Question 1.
Give an account of agriculture of the Cholas.
Answer:
Agriculture
Many of the achievements of the Cholas were made possible through new developments in agriculture.
The river Kaveri branches off into several small channels before falling into the Bay of Bengal.

  • These channels overflew frequently.
  • They deposited fertile soil on their banks. ‘
  • Water from the channels provide the necessary moisture for agriculture, particularly in the cultivation of rice.

Although agriculture had developed earlier in other parts of Tamil Nadu, it was only from the fifth or sixth century that this area was opened up for large-scale cultivation.

  • Forests had to be cleared in some regions.
  • Land was levelled in the other areas.
  • In the Kaveri delta region embankments were built to prevent flooding.
  • Canals were constructed to carry water to the fields.

In many areas two crops were grown in a year.

Question 2.
Describe the variety of irrigation methods used in the Tamil region.
Answer:
Large scale cultivation was developed in Tamil Nadu and in many cases artificial irrigation became necessary. A variety of methods were used:

  • Wells were dug
  • Huge tanks were constructed to collect rain water
  • Canals were constructed

All this work required planning, organising labour and resources. Decisions were taken collectively on the usage of water. New rulers and people took active interest in these activities.

The Administration of the Empire

Question 1.
Give an account of the administration of the Chola empire.
Answer:
The Administration of the Chola Empire

  • Settlements of peasants, known as ur, became prosperous with the spread of irrigation and agriculture.
  • Groups of villages formed larger units called nadu.
  • The village council and the nadu had several administrative functions including dispensing justice and collecting taxes.

Question 2.
Who exercised control in the affairs of ‘nadu’?
Answer:

  • Rich peasants of the Vellala caste exercised considerable control over the affairs of tjie nadu under the supervision of the central Chola government.
  • The Chola kings gave some rich landowners titles like muvendavelan / araiyar {chief), etc. as markers of respect.
  • A velan or peasant is a person who serves three kings.
  • They were given important offices of the state at the centre.
  • Brahmanas often received land grants or brahmadeya. Hence, a large number of Brahmana settlements emerged in the Kaveri valley in the same way as in other parts of south India.

Question 3.
Who looked after the Brahmadeya*?
Answer:
Each brahmadeya. was looked after by an assembly or sabha of prominent Brahmana landholders.

  • These assemblies worked very efficiently.
  • Their decisions were recorded in detail in inscriptions, often on the stone walls of temples.
  • Associations of traders known as nagarams also occasionally performed administrative functions in towns.

Question 4.
What types of land are described in the inscriptions?
Answer:
Types of Land
Chola inscriptions, mention several categories of land.

  1. Vellanvagai
    Land of non-Brahmana peasant proprietors.
  2. Brahmadeya
    Land gifted to Brahmanas.
  3. Shalabhoga
    Land for the maintenance of a school.
  4. Devadana, tirunamattukkani
    Land gifted to temples.
  5. Pallichchhandam
    Land donated to Jaina institutions.

Question 5.
How were sabhas organised?
Answer:
According to inscriptions from Uttaramerur in Chingleput district, Tamil Nadu, the sabhas were organised in the following manner:

  • The sabha had separate committees to look after irrigation works, gardens,
    temples, etc.
  • Names of eligible members of these committees were written on small tickets of palm leaf and kept in an earthenware pot.
  • A young was asked to pick the tickets, one by one for each committee.
  • The members who were picked up, formed the Sabha.

Question 6.
How did the Sabha work?
Answer:
The working of a sabha according to the Uttaramerur inscription is given below:

  • All those who wish to become members of the sabha should be owners of land from which land, revenue is collected.
  • They should have their own homes.
  • They should be between 35 and 70 years of age.
  • They should have knowledge of the Vedas.
  • They should be well-versed in administrative matters and honest in all dealings.
  • If anyone has been a member of any committee in the last three years, he cannot become a member of another committee.
  • Anyone who has not submitted his accounts, as well as those of his relatives, cannot contest the elections.

Question 7.
Describe the lives of ordinary men and women during the Chola empire.
Answer:
Chola empire Periyapuranam, a twelfth-century Tamil work, informs us about the f lives of ordinary men and women in the following manner:

  • On the outskirts of Adanur was a small hamlet of Pulaiyas, it is a name used for a social group considered “outcastes” by Brahmanas and Vellalas.
  • The hamlet was studded with small huts under old thatches and inhabited by agrarian labourers engaged in menial occupations.
  • The thresholds of the huts were covered with strips of leather, little chickens ” moved about in groups, dark children who wore bracelets of black iron were prancing about, carrying little puppies…. In the shade of the marudu (Arjuna) trees, a female labourer put her baby to sleep on a sheet of leather, there were mango trees from whose branches drums were hanging; and under the coconut ” palms, in little hollows on the ground, tiny-headed bitches lay after whelping. The red-crested cocks crowed before dawn calling the brawny Pulaiyar (plural) to their day’s work; and by day, under the shade of the Kanji tree spread the voice of the wavy-haired Pulaiya women singing as they were husking paddy…

 

 

 

 

 

 

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CHAPTER – 1 Tracing Changes Through a Thousand | CLASS 7TH | NCERT HISTORY IMPORTANT QUESTIONS & MCQS | EDUGROWN

Chapter - 1 Tracing Changes Through a Thousand

MCQs

Question 1.
Cartographer is a person who makes:
(a) Cartoons
(b) Caricatures
(c) Maps
(d) None of these

Answer

Answer: (c) Maps


Question 2.
In which century Babur used Hindustan to describe geography of subcontinent?
(a) 17th century
(b) 18th century
(c) 16th century
(d) None of these

Answer

Answer: (c) 16th century


Question 3.
Why do historians today have to be careful about the terms in the past?
(a) Because they do not know the meaning of terms
(b) Because the terms may have more than one meaning
(c) Because the terms meant different in the past
(d) None of the above

Answer

Answer: (c) Because the terms meant different in the past


Question 4.
Which of the following is not the meaning of foreigner’ in the past?
(a) Stranger
(b) Pardesi
(c) Ajnabi
(d) Indigenous

Answer

Answer: (d) Indigenous


Question 5.
In which period did the number and variety of textual records increase dramatically?
(a) 600 to 700
(b) 700 to 800
(c) 800 to 1000
(d) 700 to 1750

Answer

Answer: (d) 700 to 1750


Question 6.
Which type of people collected Manuscripts?
(a) Poor people
(b) Wealthy people
(c) Local people
(d) None of these

Answer

 


Question 7.
Where were the manuscripts placed?
(a) At home
(b) In libraries
(c) In archives
(d) Both (b) and (c)

Answer

Answer: (d) Both (b) and (c)


Question 8.
Ziyauddin Barani wrote his Chronicle first in
(a) 13th century
(b) 12th century
(c) 14th century
(d) 15th century

Answer

Answer: (c) 14th century


Question 9.
In which centuries was the term ‘Kshatriya’ applied more generally to a group of warriors?
(a) Between the eighth and fourteenth centuries
(b) Between the nineteenth and twentieth centuries
(c) Between the fourteenth and fifteenth centuries
(d) None of the above

Answer

Answer: (a) Between the eighth and fourteenth centuries


Question 10.
Which language was spoken during 14th century in present Bengal region?
(a) Awadhi
(b) Gauri
(c) Telangani
(d) Lahori

Answer

Answer: (b) Gauri


Question 11.
Which is the holy book of Muslims?
(a) Gita
(b) Adi-Puran
(c) Quran
(d) Ramayana

Answer

Answer: (c) Quran


Question 12.
Who had accepted the authority of the early Muslim leaders?
(a) Sunnis
(b) Shias
(c) Khalifas
(d) None of these

Answer

Answer: (a) Sunnis


Question 13.
Prosperity in the subcontinent attract trading companies of which region?
(a) European
(b) Australian
(c) Russian
(d) None of these

Answer

Answer: (a) European


Match the contents of Column A with that of Column B:

Column AColumn B
1. Chronicler(a) dense and difficult
2. Poet(b) Al-Idrisi
3. Nastaliq style(c) Minhjaj-i-Siraj
4. Shikaste style(d) cursive and easy
5. Cartographer(e) Amir Khusrau
Answer

Answer:

Column AColumn B
1. Chronicler(c) Minhjaj-i-Siraj
2. Poet(e) Amir Khusrau
3. Nastaliq style(a) dense and difficult
4. Shikaste style(d) cursive and easy
5. Cartographer(b) Al-Idrisi

Fill in the blanks with appropriate words:

1. ………… provide a lot of information to the historians.

Answer

Answer: Manuscripts


2. Rules and regulations of jatis were enforced by …………

Answer

Answer: Jati Panchayat


3. Knowledge of ………… earned Brahmanas a lot of respect.

Answer

Answer: Sanskrit


4. The Muslims had two divisions the ………… and the …………

Answer

Answer: Shias, Sunnis


5. ………… had controlled an empire from Bengal in the east to Ghazni in the west.

Answer

Answer: Balban


State whether the given statements are true or false:

1. Science of cartography differed between 12th and 13th century.

Answer

Answer: True


2. We have many original manuscripts to get information.

Answer

Answer: False


3. Between 8th and 14th century the term Kshatriya was used for group of Brahmanas.

Answer

Answer: False


4. Status of a jati remained same from region to region.

Answer

Answer: False


4. Muslims had two schools of law hanafi and shafi’i.

Answer

Answer: True

Question 1.
What is the difference between the two maps of India made in 1154 and 1720?
Answer:
Al-Idrisi an Arab cartographer made a map in 1154 CE. French cartographer made the map of same area in 1720’s. The two had certain differences:

  • Al-Idrisi’s map had south India in place of north India. Sri Lanka was at the top.
  • Place names are marked in Arabic. Kanauj is spelt as Qanauj and is shown in Uttar Pradesh.
  • French cartographer’s map was made about 600 years later. There were many changes by the time.
  • This map is more familiar. Coastal areas are more detailed.
  • This map was used by the European sailors and merchants on their voyages.

Question 2.
What precautions historians should follow while reading the maps?
Answer:
Historians reading the maps, documents or texts from the past should be sensitive about the contends. They should keep in mind the different historical background. Equally important is the fact that the science of cartography differ from period to period.

New and Old Terminologies

Question 1.
Does the information given in historical records change over the years?
Answer:
Historical records exists in a variety of languages. These languages changed over time. For example, Medieval Persian is different from modem Persian in grammar, vocabulary and even meaning of words.

Question 2.
How has the term ‘Hindustan’ changed over the centimes?
Answer:
The meaning of the term ‘Hindustan’ has changed over the centuries in the following manner:

  • In the thirteenth century Minhaj-i-Siraj used the term ‘Hindustan’. He meant areas of Punjab, Haryana and the lands between Ganga and Yamuna. He used this term in a political sense that were a part of the dominions of the Delhi Sultanate. The term never included South India.
  • In the sixteenth century poet Babur used the term ‘Hindustan’ to describe the geography, the fauna and the culture of the inhabitants of the subcontinent.
  • In fourteenth century poet Amir Khusrau used the term ‘Hind’ in the same sense as Babur did in the sixteenth century.
  • ‘Hindustan’ did not carry the political and national meanings as the term ‘India’ does today.

Question 3.
How are historians to be careful about the term they use as they go on changing with time?
Answer:
Historians are to be careful about the terms they use because their meanings go on changing with change in time.

Example:
We take a simple term ‘Foreigner’.

  • It is used today to mean a person who is not an Indian.
  • In the medieval period a ‘foreigner’ was any stranger who was not a part of that society or culture.
  • In Hindi the term pardesi is used to describe such a person and in persian, ajnabi.
  • A city-dweller regarded a forest-dweller as a ‘foreigner’ but two peasants living in the same village were not foreigners to each other, though they belonged to different religions or caste backgrounds.

Historians and Their Sources

Question 1.
What are the sources used by the historians to study the past?
Answer:
Historians use variety of sources to study the past. It depends upon the period of their study and nature of study. They use those resources that provide some continuity. Historians still rely on coins, inscriptions, architecture and textual records.
There appeared some discontinuity as well. The variety of textual records increased from 700 to 1750. They slowly replaced other types of available sources. During this period paper gradually became cheaper and easily available.

Question 2.
What was the result of easy availability of paper in the 14th century?
Answer:

  • People used paper to write holy texts, chronicles of rulers, letters and teachings of saints, petitions and judicial records and in preparing accounts and taxes.
  • Manuscripts were collected by wealthy people, rulers, monasteries and temples.
  • They were placed in libraries and archives.
  • They provided a lot of detailed information to historians.
  • Manuscripts were difficult to use.

Question 3.
What was the result of non-availability of printing press in the 13th and 14th centuries?
Answer:
Historians faced a lot of difficulties while using manuscripts because:

  • There was no printing press in the 13th and 14th centuries. Scribes in those days made manuscripts by hand.
  • To copy was not an easy exercise. Scribes could not read the handwriting of the other writers.
  • They were forced to guess. So there were small but significant differences in the copy of the scribed.
  • These small words or sentences here and there grew over centuries of copying.
  • The manuscripts of the same text became a great extent different from the original.

Question 4.
Describe the problem of dearth of original manuscripts of the authors.
Answer:
There is a serious problem because we rarely find the original manuscripts of the authors today.

  • We are totally dependent upon the copies made by later scribes.
  • The result is that historians have to read different manuscript versions of the same text to guess what the author had originally written.
  • On several occasions authors revised their chronicles at different times.
  • The fourteenth century chronicler Ziyauddin Barani wrote his chronicle first in 1356 and another version came two years later.
  • The two versions differ from each other.
  • Historians did not know about the existence of the first version until 1960s.
  • It remained lost in large library collections.

New Social and Political Groups

Question 1.
How is the study of the thousand years between 700 and 1750 a huge challenge to historians?
Answer:
The study of the thousand years between 700 and 1750 is a huge challenge to historians because of

  • Scale and variety of developments that occurred during this period.
  • At various moments in this period new technologies made their appearance.
  • All the innovations, new technologies and crops came along with people. They brought other ideas with them as well.
  • In this way, this was a period of economic, political, social and cultural changes.

Question 2.
What were the new technological advancement between 700 and 1750?
Answer:
Some of the technological changes associated with this period are:

  • Persian wheel in irrigation.
  • Spinning wheel.
  • Fire-arms in combat.

Question 3.
Which are the; other new things happening during this period?
Answer:
During this period many things were happening like:

  • New foods and beverages like potatoes, com, chillies, tea and coffee arrived in the subcontinent.
  • Groups of people travelled long distances in search of new opportunities.
  • The subcontinent held immense wealth and many possibilities for people to get a fortune.

Question 4.
What does the word ‘Rajputs’ stand for?
Answer:
‘Rajputs’ word has been derived from Rajaputra’ the son of a ruler. Between the eighth and the fourteenth centuries the term was applied more generally to a body of warriors who claimed Kshatriya caste status. The term included not just rulers and chieftains but also soldiers and commanders.

They served in the armies of different monarchs all over the subcontinent. A chivalric code of conduct, including extreme valour and a great sense of loyalty were the qualities attributed to Rajputs by their poets and bards.

Question 5.
Name the various groups that became important between 700-1750.
Answer:
The various groups that became politically important between 700 and 1750 were Rajputs, Sikhs, Marathas, Jats, Ahoms, Kayasthas etc.

Question 6.
What nugor changes occurred between 700 and 1750 A.D.?
Answer:

  • Throughout the period between 700 and 1750 there was a gradual clearing of forests and the extension of agriculture. This was a change faster and more complete in some areas than in others.
  • Changes in their habitat forced many forest-dwellers to migrate.
  •  Others started tilling the land and became peasants.

Regional markets, chieftains, priests, monasteries and temples began to influence them.

  • They became part of large complex societies.
  • They were required to’ pay taxes and offer goods and services to local lords.

As a result, significant economic and social differences emerged among the peasants.

  • Some possessed more productive land.
  • Others kept cattle,
  • Yet others combined artisanal work with agricultural activity during the lean season.

Question 7.
How were the people grouped into jatis?
Answer:
As society became more uneven people were grouped into jatis or sub-castes and ranked on the basis of their backgrounds and their occupations.
Ranks were not fixed permanently:

  • They varied according to the power, influence and resources controlled by members of the jati.
  • The status of the same jati could vary from area to area.

Question 8.
How were the jatis regulated?
Answer:
The affairs of jatis were regulated in the following way:

  • Jatis formed their own rules and regulations.
  • There was an assembly of elders called jati panchayat.
  • It enforced the rules and regulations.
  • Jatis were also directed to follow the rules of the village.
  • Several villages were governed by a chieftain.

Question 9.
What is the contribution of the medieval period to the Indian history?
Answer:
Medieval period (due to its contribution) is considered very important in the Indian history. We can mention its contribution in following points:

  1. Many modem languages, which we speak nowadays in India, developed at this time.
  2. Some of the food items we eat and the clothes we wear became popular during this age.
  3. The history of many of our current religious faiths (such as Islam, Sikhism, etc.) can be traced back to this period.

Region and Empire

Question 1.
What was the extent of Balban’s empire?
Answer:
Ghiyasuddin Balban (1266-1287) claimed himself to be the ruler of vast empire. It stretched from Bengal (Gauda) in the east to Ghazni (Gajjana) in Afghanistan in the west. It included all of south India.

People from different regions-Gauda, Andhra, Kerala, Karnataka, Maharashtra and Gujarat fled before his armies came. Historians regard this as exaggerated claims. It is a question of debate why rulers kept claiming about their conquests.

Question 2.
Explain the features of regions by 700 A.D.
Answer:

  • By 700 A.D. regions already possessed distinct geographical dimensions.
  • They had their own language and cultural characteristics.
  • They were also associated with specific ruling dynasties.
  • Thfere was considerable conflict between these states.
  • Occasionally dynasties like the Cholas, Khiljis, Tughluqs and Mughals were able to build an empire that was pan-regional, covering various regions. These empires were not equally stable or successful.

Question 3.
What did the decline of the Mughal Empire lead to in the 18th century?
Answer:

  • When the Mughal Empire declined in the eighteenth century, it led to the re-emergence of regional states.
  • Years of imperial, pan-regional rule had altered the character of the regions.
  • Across most of the subcontinent the regions were left with the legacies of the big and small states that ruled over them.
  • This was clear in the emergence of many distinct and shared traditions: in the way of governance, the management of the economy, elite cultures, and language.
  • Through the thousand years between 700 and 1750 A.D. the character of the different regions did not grow in isolation.
  • They felt the impact of larger pan-regional forces of integration without losing their own character.

Old and New Religions

Question 1.
What developments have taken place in religious traditions during this period?
Answer:
During the thousand years there were many developments in religious traditions. People’s belief in divine was personal and collective. Collective belief was in supernatural agency-religion. It was connected to social and economic aspects of local communities. With the changes in social aspects the religious beliefs also changed.

Question 2.
Describe the major development in Hindu religious traditions during the period 700 to 1750 A.D.
Answer:

  • The thousand years of history between 700 and 1750 A.D. witnessed major developments in religious traditions.
  • It was during this period that important changes occurred in Hinduism.
  •  The worship of new deities.
  • The construction of temples by royalty.
  • Their knowledge of Sanskrit texts earned the Brahmanas a lot of respect in society and support of new rulers or patrons searching for prestige.
  • One of the major developments was the emergence of the idea of Bhakti.
  • It was of a loving, personal deity that devotees could reach without the aid of priests or elaborate rituals.

Question 3.
Which new religion came to India during the period between 700 and 1750 A.D.?
Answer:
The period between 700 and 1750 A.D. was the period when new religions appeared in the subcontinent.
Merchants and migrants first brought the teachings of the holy Quran to India in the seventh century. Many rulers were patrons of Islam, Jurists and theologians.

  • Muslims regard the Quran as their holy book.
  • They accept the sovereignty of the one God or Allah.
  • Islam was interpreted in a variety of ways by its followers:
  • Shia Muslims believed that the prophet’s son-in-law, Ali, was the legitimate leader of the Muslim community.
  • Sunni Muslims accepted the authority of the early leaders (Khalifas) of the community, and the succeeding Khalifas.
  • There were other important differences between the various schools of law and in theology and mystic traditions.
  • The schools of law are Hanafi and Shafi’i, mainly in India.

Thinking about Time and Historical Periods

Question 1.
How do historians divide the history of India into three periods? What are the drawbacks of this division?
Answer:
According to historians time reflects changes in social and economic organisation, in transformation of ideas and beliefs. They do not see it as clock or calender.

The study of time is made somewhat easier by dividing the past into large segments. They are called periods. The periods possess shared characteristics.

In the middle of the nineteenth century British historians divided the history of India into three periods.

  • They are ‘Hindu’, ‘Muslim’ and ‘British’.
  • This division was based on the idea that the religion of rulers was the only important historical change, and that there were no other significant developments in result of the economy, society or culture.
  • Such a division also ignored the rich diversity of the subcontinent. Few historians follow this periodisation today. Most look to economic and social factors to characterise the major elements of different moments of the past.

Question 2.
What is included in the study of history?
Answer:
Early history included study of different societies—hunter gatherers, early farmers, people in towns and villages, early empires and kingdoms.

The medieval history is more about peasant societies, rise of regional or imperial states, the growth of Hinduism and Islam as religions. It also includes the arrival of European trading companies.

Question 3.
Why there is a problem in studying a long period of history as one unit?
Answer:
Thousand years of history is full of change. 16th and 17th centuries were different from 8th or 11th centuries. Therefore entire period cannot be described as one unit.

Modem period is associated with material and intellectual progress. But, this does not mean the medieval period had no development at all. All this creates confusion, hence periodisation was required.

During these thousand years the societies of subcontinent were developed and economies too prospered. This attracted interest of European trading companies.

 

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CHAPTER – 18 Wastewater Story | CLASS 7TH | NCERT SCIENCE IMPORTANT QUESTIONS & MCQS | EDUGROWN

SCIENCE IMPORTANT QUESTIONS & MCQS FOR CLASS 7th

Get Chapter Wise MCQ Questions for Class 7 Science with Answers prepared here according to the latest CBSE syllabus and NCERT curriculum. Students can practice CBSE Class 7 Science MCQs Multiple Choice Questions with Answers to score good marks in the examination.  Students can also visit the most accurate and elaborate NCERT Solutions for Class 7Science. Every question of the textbook has been answered here.

Chapter - 18 Wastewater Story

Question 1.
Which one of the following is a quality of wastewater?
(a) Foul smell
(b) Bad taste
(c) Dirty look
(d) All of these

Answer

Answer: (d) All of these


Question 2.
Period 2005-2015 is being celebrated as the international decade for action on
(a) water for life
(b) education for all
(c) global war
(d) terrorism

Answer

Answer: (a) water for life


Question 3.
In sewerage manholes are located at every
(a) 20-25 m
(b) 50-60 m
(c) 90-100 m
(d) 100-110 m

Answer

Answer: (b) 50-60 m


Question 4.
Which one of the following is a step in wastewater treatment?
(a) Aeration
(b) Filtration
(c) Chlorination
(d) All of these

Answer

Answer: (d) All of these


Question 5.
Sludge in separate tanks is decomposed to get biogas by
(a) yeasts
(b) aerobic bacteria
(c) anaerobic bacteria
(d) none of these

Answer

Answer: (c) anaerobic bacteria


Question 6.
Which one of the following is used in vermi-processing toilet?
(a) Earthworm
(b) Cockroach
(c) Both of these
(d) None of these

Answer

Answer: (a) Earthworm


Question 7.
Sewage is mainly a
(a) liquid waste
(b) Solid waste
(c) gaseous waste
(d) Mixture of solid and gas

Answer

Answer: (a) liquid waste


Question 8.
Which of the following is/are products of wastewater treatment?
(a) Biogas
(b) Sludge
(c) Both Biogas and sludge
(d) Aerator

Answer

Answer: (c) Both Biogas and sludge


Question 9.
Open drain system is a breeding place for which of the following:
(a) Files
(b) Mosquitoes
(c) Organisms which cause diseases
(d) All of these

Answer

Answer: (d) All of these


Question 10.
Which of the following is not a source of waste water?
(a) Sewers
(b) Homes
(c) Industries
(d) Hospitals

Answer

Answer: (a) Sewers


Match the following:

Column AColumn B
(i) Sewerage(a) Decompose sludge
(ii) Bar screens(b) Used in vermi-processing toilet
(iii) Anaerobic bacteria(c) Remove large objects from wastewater
(iv) Cooking oil and fats(d) Disinfect water
(v) Earthworm(e) Block the pipes
(vi) Chlorine and ozone(f) Transport system that carries sewage
Answer

Answer:

Column AColumn B
(i) Sewerage(f) Transport system that carries sewage
(ii) Bar screens(c) Remove large objects from wastewater
(iii) Anaerobic bacteria(a) Decompose sludge
(iv) Cooking oil and fats(e) Block the pipes
(v) Earthworm(b) Used in vermi-processing toilet
(vi) Chlorine and ozone(d) Disinfect water

Fill in the blanks:

1. ………………… is generated in homes, industries, agricultural field and in other human activities. This is called …………………

Answer

Answer: Wastewater, sewage


2. Sewage is a liquid waste which causes ………………… and ………………… pollution.

Answer

Answer: water, soil


3. Wastewater is treated in ………………… treatment plant.

Answer

Answer: wastewater/sewage


4. Byproducts of wastewater treatment are ………………… and …………………

Answer

Answer: sludge, biogas


5. Open drain system is a breeding place for flies, mosquitoes and organisms which cause …………………

Answer

Answer: diseases


6. Dried sludge is used as …………………

Answer

Answer: manures


Choose the true and false statements from the following:

1. Wastewater cannot be reused.

Answer

Answer: False


2. Treatment plants reduce pollutants in wastewater to a level where nature can take care of it.

Answer

Answer: True


3. Poor sanitation and contaminated drinking water is the cause of a large number of diseases.

Answer

Answer: True

Question 1.
Wastewater is fit for human consumption or not. Give reason to support your answer.
Answer:
No, because it is dirty and has many diseases causing organisms like cholera, typhoid, etc.

Question 2.
Name two chemicals used to disinfect wastewater.
Answer:
Chlorine and ozone.

Question 3.
Special type of toilets has been designed in aeroplanes, name it.
Answer:
Vacuum toilets.

Question 4.
Name the toilets used in areas with limited water supply.
Answer:
Vermi-processing toilets.

Question 5.
Name the type of toilets which are most suitable for holding an outdoor music festival in a park.
Answer:
Chemical toilets.

Question 6.
Name two things that can be made from sludge extracted during treatment of sewage.
Answer:
Biogas and manure.

Question 7.
The Eucalyptus trees are planted along sewage ponds. Give reason. [HOTS]
Answer:
The Eucalyptus trees are planted along sewage ponds because these trees absorb all surplus wastewater rapidly and release pure water vapour into the atmosphere.

Question 8.
One can avoid the addition of the load in WWTP. Justify.
Answer:
By following proper sanitation and house-keeping practices, by creating less waste at an individual level, we can avoid the addition of the load in wastewater treatment plant.

Question 9.
Name two inorganic impurities present in sewage. [NCERT Exemplar]
Answer:
Inorganic impurities present in sewage are nitrates and phosphates.

Question 10.
Mention the use of dried sludge.
Answer:
It is used as manure, thus returning organic matter and nutrients to the soil.

Question 11.
In which type of toilets, human excreta is treated by earthworm?
Answer:
Vermi-processing toilets.

Question 12.
Give some examples of onsite sewage disposal systems.
Answer:
Chemical toilets, septic tanks, composting pits, etc.

Question 13.
Sewage contains some organic impurities in it. Name them.
Answer:
Human faeces, animal wastes, oil, urea pesticides, herbicides, fruits and vegetables are the organic impurities present in sewage.

Question 14.
Mention the common process of cleaning of wastewater.
Answer:
Sewage treatment.

Question 15.
World Water Day is celebrated on
Answer:
22 March.

Question 16.
Mention the period proclaimed as the International Decade for action on Water for Life.
Answer:
2005-2015 is the period proclaimed as the International Decade for action on Water for Life.

Question 17.
Name the three processes involved in treatment of wastewater.
Answer:
Treatment of wastewater involves physical, chemical and biological processes for removing different types of contaminants.

Question 18.
Explain sewers and sewage.
Answer:
Sewers are the pipes acting as a transport system that carries sewage from point of origin to the point of disposal. The wastewater released from homes, industries, hospitals, offices and other uses is called sewage.

Question 19.
The used water should not be wasted. Do you agree? Justify.
Answer:
The used water should not be wasted but it should be cleaned.

Question 20.
Bleaching powder is mixed in water, why? Think and give appropriate reason for it. [HOTS]
Answer:
Bleaching powder is mixed in water to make it safe for drinking because it kills the harmful germs present in water.

Question 21.
Natural water is the purest form of water. Explain why or why not.
Answer:
Natural water is not pure always. It is because all types of water except rainwater contain salts dissolved in it. These salts make the water impure.

Question 22.
Mention the role of effluent treatment plants in cities.
Answer:
The effluent treatment plants filter out undissolved materials form water.

Question 23.
Protozoa is causative organism of which waterborne disease?
Answer:
Dysentry.

Question 24.
In the chemical process of water treatment, water is treated with some chemicals. Describe chlorination in light of it. [HOTS]
Answer:
Chlorination is the process of adding chlorine (chemical) in water to make it safe for drinking.

Question 25.
Sanitation can be improved. Explain, what step should be taken to improve it.
Answer:
Low cost onsite sewage disposal system must be encouraged to improve sanitation.

Question 26.
Give the percentage of water being activated in sludge.
Answer:
About 97% of water is being activated in sludge.

Question 27.
Animal waste, oil and urea are some of the organic impurities present in sewage. Name two more organic impurities present in sewage. [NCERT Exemplar]
Answer:
Fruits and vegetable wastes, pesticides and herbicides are organic impurities present in sewage other than animal wastes, oil and urea.

Wastewater Story Class 7 Science Extra Questions Short Answer Type Questions

Question 1.
Open drain is a big concern now-a-days. Justify.
Answer:
Open drain is a big concern for the society now-a-days because they create unhygienic conditions. It provides favourable conditions to flies, mosquitoes and other insects to breed and spread a number of diseases.

Question 2.
Explain, how sewage is disposed of in an aeroplane.
Answer:
Aeroplanes have their closed waste sewage tanks in them, which suck the wastewater and collect it in their tanks.
Once the aeroplane lands on the ground, the crew disposed of the sewage properly into airport sewage facility.

Question 3.
Sewage also contains some nutrients Comment.
Answer:
Sewage is a complex mixture which contains suspended solids, organic and inorganic impurities, nutrients, saprotrophic and disease causing bacteria and other microbes.
The nutrients present in sewage are phosphorus and nitrogen.

Question 4.
Suggest two alternative arrangements for sewage disposal where there is no sewerage system.
Answer:
The two alternative arrangements for sewage disposal, where there is no sewerage system are as below

  • Septic tanks
  • Composting pits.

Question 5.
Recall and enlist some better house keeping practices.
Answer:
We must minimise and manage waste at our houses before its disposal in the following manner:

  • Cooking oil and fats should not be thrown down the drain. They can harden and block the pipes. In an open drain the fats clog the soil pores reducing its effectiveness in filtering water. Throw oil and fats in the dustbin.
  • Used tealeaves, solid food remains, soft toys, cotton, sanitary towels, etc., should also be thrown in the dustbin. These wastes choke the drains. They do not allow free flow of oxygen. This hampers the degradation process.
  • The chemicals like paints, solvents, insecticides, medicines and motor oils should 1 State the role of screen bars in wastewater treatments, not be thrown in drains as they kill helpful 2 Chlorination makes water fit for human consumption. How? microbes which digest the organic waste.

Question 6.
Water in a river is cleaned naturally. Do you agree? Think and explain. [HOTS]
Answer:
Yes, river water is cleaned naturally by a process that is similar to wastewater treatment plant.
As muddy water when flows through grass or weeds on its way to a stream, mud and solid particles get filtered out. At the bottom of a lake or stream, microorganism brings chemical changes in the water. The natural filtration process removes pollution from the roundwater throughout the process making it clean and fit for drinking.

Question 7.
The terms sewage, sewers and sewerage are interlinked with each other. Can you explain, how? [NCERT Exemplar]
Answer:
The terms like sewage, sewers and sewerage are interlinked with each other because sewage is a mixture of wastewater coming out of homes and other places. Sewers are pipes which carry sewage and sewerage is a network of sewage carrying pipes.

Question 8.
Describe onsite disposal systems.
Answer:
Some organisations offer hygienic onsite human waste disposal technology. These toilets do not require scavenging. Excreta from the toilet seats flow through covered drains into a biogas plant. The biogas produced is used as a source of energy.

Question 9.
A sewage treatment plant involves few steps in its working.
Aeration tank, grit and sand removal tank, second sedimentation tank, bar screen, first sedimentation tank.
(a) Arrange all the above steps in the correct order in which they occur in the sewage treatment plant.
(b) Which step gives most of the sludge? [HOTS]
Answer:
(a) Bar screen, grit and sand removal tank, first sedimentation tank, aeration tank, second sedimentation tank.
(b) First sedimentation tank.

Question 10.
Give reasons for each of the following.
(a) We should not throw used tea leaves into sink.
(b) We should not throw cooking oil and fats down the drain. [NCERT Exemplar]
Answer:
(a) We should not throw used tea leaves into sink because it may choke the drain-pipe of the sink.
(b) We should not throw cooking oil and fats down the drain as it can harden and block the drain-pipes.

Question 11.
Given below is a jumbled sequence of the processes involved in a wastewater treatment plant. Arrange them in their correct sequence.
(a) Sludge is scraped out and skimmer removes floating grease.
(b) Water is made to settle in a large tank with a slope in the middle.
(c) Large objects like plastic bags are removed by passing wastewater through bar screens.
(d) Sand, grit and pebbles are made to settle by decreasing the speed of incoming wastewater.
(e) Wastewater enters a grit and sand removal tank. {NCERT Exemplar]
Answer:
The correct sequence of wastewater treatment in treatment plant is
(c) Large objects like plastic bags are removed by passing wastewater through bar screens.
(e) Wastewater enters a grit and sand removal tank.
(d) Sand, grit and pebbles are made to settle by decreasing the speed of incoming wastewater.
(b) Water is made to settle in a large tank with a slope in the middle.
(a) Sludge is scraped out and skimmer removes the floating grease.

Question 12.
Can we contribute in sanitation at public places? Explain.
Answer:
Yes, we all have a role to play in keeping our environment clean and healthy. All of us can contribute in maintaining sanitation at public places. We should not scatter litter anywhere. If there is no dustbin in sight, we should carry the litter home and throw it in the dustbin.

Question 13.
Three statements are provided here which define the terms, i.e. sludge, sewage and wastewater.
Pick out the correct definition for each of these terms.
(a) The settled solids that are removed in wastewater treatment with a scraper.
(b) Water from kitchen used for washing dishes.
(c) Wastewater released from homes, industries, hospitals and other public buildings. [NCERT Exemplar]
Answer:
(a) The settled solids that are removed in wastewater treatment with a scraper is sludge.
(b) Water from kitchen which is used for washing dishes is wastewater.
(c) Wastewater released from homes, industries, hospitals and other public buildings is sewage.

Question 14.
A man travelling in a train threw an empty packet of food on the platform. Do you think this is a proper waste disposal method? Elaborate. [NCERT Extmplar; HOTS]
Answer:
No, one must always put the waste in a nearby dustbin or carry it home and dispose it in dustbins there.
Waste, not properly disposed may enter into the drains and choke them. It also makes public places dirty and unhygienic.

Question 15.
With reference to the treatment of polluted water at home by aeration, filtration, chlorination processes answer the following questions.
(a) What changes did we observe in the appearance of liquid after aeration? Did aeration change the odour?
(b) What is removed by the sand filter?
(c) Does chlorine change the colour of treated water?
(d) Do chlorine have an odour?
Answer:
(a) Aerated water contains some suspended impurities and the foul odour of the polluted water disappears completely after aeration.
(b) Sand filter removes tiny suspended impurities.
(c) Chlorine makes the water clear and colourless.
(d) Yes, chlorine have a peculiar odour which is not worse than wastewater.

Question 16.
Observe the given figure and answer the following:
(a) What does this figure show?
(b) State the functions of each part of the figure? [HOTS]
Wastewater Story Class 7 Extra Questions Science Chapter 18 1
Answer:
(a) This figure shows the supply of drinking water, its processing and its source as well. Functions of each part of the figure.
(b)

  • River It is the source of water.
  • Pumping station Pump the water to collect it in reservoir.
  • Sedimentation tank Impurities are settle in the bottom of tank.
  • Sand and gravel and sand filter Remove the dirt from the water.
  • Chlorinating tank Chlorine is mixed in water to disinfect the eater and to kill the germs.
  • To overhead tank Purified water is stored in this tank for supply to the households for drinking.

Question 17.
Complete .the table given below of the contaminant survey.

Types of sewagePoint of originSubstances which contaminateAny other remark
Sullage waterKitchen  
Foul wasteToilets  
Trade wasteIndustrial and commercial organisations  

Answer:
Given below is the table of contaminant survey explaining types of sewage with their point of origin an contaminate in them.

Type of sewagePoint of originSubstances which contaminateAny other remark
Sullage waterKitchenCooking oils, fats, etc.May choke drains
Foul wasteToiletsFaeces and urineCause diseases like dysentery, cholera, etc
Trade wasteIndustrial and commercial organisationsChemicals like paints, solvents, motor oil, etc.Causes water and soil pollution

Wastewater Story Class 7 Science Extra Questions Long Answer Type Questions

Question 1.
Explain the different types of inorganic and organic impurities generally present in sewage.
Answer:
It is wastewater released by homes, industries agricultural fields and other human activities. It also includes rainwater that has run down the street during a storm or heavy rain and it is a liquid waste. Most of its water has dissolved and suspended impurities called contaminants.
Composition of Sewage
The following components make the sewage:

  • The organic impurities present in sewage are human faeces, animal wastes (like animal dung), urea (as urine), oil, fruits and vegetable wastes, pesticides, herbicides, etc.
  • The inorganic impurities present in sewage are nitrates, phosphates and metals.
  • The nutrients present in sewage are nitrogen and phosphorus.
  • The bacteria present in sewage include those bacteria which cause water-borne diseases such as cholera and typhoid.
  • The other microbes present in sewage are Protozoa which cause a water-borne disease called dysentery.

Question 2.
Describe septic tank. How does it function?
Answer:
Low cost outside sewage disposal system have been developed to take care of places where there is no sewage system, e.g. rural areas, isolated buildings. These are described below:
(i) Septic tanks Septic tank is a low cost onsite sewage disposal system. Septic tanks are suitable where there is no sewerage made. These tanks need cleaning every four to six months.

A septic tank usually consists of a big, covered underground tank made of concrete having an inlet pipe at one end and on outlet pipe at the other end. The toilet seat is connected to the inlet pipe of the septic tank. The human excreta from the toilet seat enters into the septic tank through the inlet pipe. The solid part of excreta keeps on collecting at the bottom of the septic tank in the form of a sludge whereas watery waste remains above it.

The anaerobic bacteria breakdown most of the solid organic matter present in human excreta due to which the volume of solid waste is reduced too much. The digested solid waste keeps on depositing at the bottom of septic tank. The watery waste is also cleaned by anaerobic bacteria. The excess water goes out of the septic tank through the outlet pipe and get absorbed in soil.

(ii) Composting pits These are self sustained human waste disposal units which is not connected to a sewer line or a septic tank. A composting toilet breaks down and dehydrate human waste to compost.

(iii) Chemical toilets These toilets have limited storage capacity for human waste and need to be emptied periodically. These are the toilets which use chemically treated reservoir located just below the toilet seats. The chemicals reduce the foul smell coming out of human excrete and carry out partial disinfection of human waste.

Question 3.
Discuss vermi-processing toilets. Name the useful product obtained from such toilets.
Answer:
In the vermi-processing toilet, the human excreta is treated by earthworms in a pit. The earthworms gradually eat up all the organic matter present in human excreta, decompose it and pass out from their body in the form of warm casting (also called vermi cakes).
The useful product obtained from a vermi-processing toilet is vermi cakes which is kind of high quality manure.

Question 4.
One day Sachin had gone to his uncle who lives in a village. He saw there a large number of people defecate in an open area because proper toilet facilities are not there. He wondered about the groundwater contamination, as he studied in his class that this act may cause water-borne diseases. He convinced village people to make toilets to avoid such an out break of water-borne diseases.
(a) Name two water-borne diseases.
(b) Explain vermi-composting toilets.
(c) What values are shown by Sachin? [Value Based Question]
Answer:
(a) Typhoid and cholera.
(b) In vermi-composting toilets, human excreta is treated by earthworms in a pit.
(c) He is intelligent and concious about health.

Question 5.
There are many alternative sewage disposal systems which have been developed as per needs of the community, persons, occasions, etc.. Few situations/specifications of the sewage need are given below. Write the name of sewage which can be used in the following conditions.
(a) A toilet which can provide high quality manure.
(b) The toilet which is used in aeroplane during flight.
(c) A toilet which can be used in some out door gathering.
(d) A toilet used in limited water supply.
(e) A toilet which contaminates water of hand pump installed nearby. [HOTS]
Answer:
(a) Vermi-composting toilets
(b) Vacuum toilets
(c) Chemical toilets
(d) Composting toilets
(e) Septic tank toilets

Question 6.
Think and suggest some ways to minimise waste and pollutants at their source, taking your home as an example.
Answer:
We can minimise waste and pollutants entering the water and create less wastewater by taking following few steps at home:

  • By not throwing used tea leaves, solid food remains, etc., in the drain. We should throw it in the dustbin.
  • By not throwing chemicals like medicines, paints, insecticides, etc., in the drain as they increase the pollution load of the sewage.

Question 7.
Trisha has seen huge garbage dumps outside the school campus which are not being regularly disposed of by municipality of the area. She discussed the problem with her biology teacher and decided to organise a rally to spread awareness among local people.
Next day she delivered this information in the assembly and convinced the school mates to join her. She also explained them about the importance of sanitation at public places which she had recently studied in biology.
(a) In your views, who is responsible to maintain sanitation at public places?
(b) What would happen, if all the wastes produced at public places are not disposed of regularly?
(c) What are the valuesS shown by Trisha? [Value Based Question]
Answer:
(a) In my opinion, municipality is responsible to maintain sanitation at public places.
(b) If all the wastes produced at public places are not disposed of regularly and properly epidemics could break out.
(c) Responsibility, sensitivity and awareness towards public hygiene.

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CHAPTER – 17 Forests: Our Lifeline | CLASS 7TH | NCERT SCIENCE IMPORTANT QUESTIONS & MCQS | EDUGROWN

SCIENCE IMPORTANT QUESTIONS & MCQS FOR CLASS 7th

Get Chapter Wise MCQ Questions for Class 7 Science with Answers prepared here according to the latest CBSE syllabus and NCERT curriculum. Students can practice CBSE Class 7 Science MCQs Multiple Choice Questions with Answers to score good marks in the examination.  Students can also visit the most accurate and elaborate NCERT Solutions for Class 7Science. Every question of the textbook has been answered here.

Chapter - 17 Forests: Our Lifeline

Question 1.
Which one of the following is not a wild animal?
(a) Bear
(b) Bison
(c) Jackal
(d) Goat

Answer

Answer: (d) Goat


Question 2.
Which one of the following is an animal product?
(a) Gum
(b) Catechu
(c) Honey
(d) Rubber

Answer

Answer: (c) Honey


Question 3.
Roof of the forest made by the branches of the tall trees is called
(a) canopy
(b) crown
(c) understoreys
(d) none of these

Answer

Answer: (a) canopy


Question 4.
Understoreys are formed due to
(a) different types of crowns
(b) different sizes of crown
(c) different heights of trees
(d) all of these

Answer

Answer: (d) all of these


Question 5.
Decomposers convert the dead plant and animal tissues into
(a) clay
(b) humus
(c) inorganic debris
(d) soil

Answer

Answer: (b) humus


Question 6.
Arrange the following components of a food chain in proper sequence – grass, frog, eagle, insects, snake.
(a) Grass → insects → frog → snake → eagle.
(b) Grass → snake → insects → frog → eagle.
(c) Grass → snake → eagle → insects → frog.
(d) All are possible

Answer

Answer: (a) Grass → insects → frog → snake → eagle.


Question 7.
Sequence that represents the series of eating and being eaten is called
(a) food series
(b) food chain
(c) food web
(d) food hub

Answer

Answer: (b) food chain


Question 8.
Which one of the following is a role of forests?
(a) Provide food, shelter, water and medicines
(b) Prevent soil erosion
(c) Prevent flood
(d) All the above

Answer

Answer: (d) All the above


Question 9.
Which among the following forest animals is the smallest?
(a) Fox
(b) Boar
(c) Bison
(d) Porcupine

Answer

Answer: (d) Porcupine


Question 10.
Which of the following is not the name of a tree?
(a) Teak
(b) Sal
(c) Porcupine
(d) Kachnar

Answer

Answer: (c) Porcupine


Match the following:

Column AColumn B
(i) Micro-organisms act upon the dead plant to produce(a) vulture
(ii) Scavenger(b) canopy
(iii) Help in maintaining the supply of nutrients to growing plants(c) food web
(iv) Roof of the forest made by the branches of tall trees(d) forest protect
(v) Number of food chain(e) autotrophs
(vi) Soil erosion(f) purifier of air and water
(vii) Green plants(g) saprotrophs
(viii) A forest acts as(h) humus
Answer

Answer:

Column AColumn B
(i) Micro-organisms act upon the dead plant to produce(h) humus
(ii) Scavenger(a) vulture
(iii) Help in maintaining the supply of nutrients to growing plants(g) saprotrophs
(iv) Roof of the forest made by the branches of tall trees(b) canopy
(v) Number of food chain(c) food web
(vi) Soil erosion(d) forest protect
(vii) Green plants(e) autotrophs
(viii) A forest acts as(f) purifier of air and water

Fill in the blanks:

1. In a forest, trees form the uppermost layer, followed by ………………. The ………………. form the lowest layer of vegetation.

Answer

Answer: shrubs, herbs


2. Different layers of vegetation provide ………………. and ………………. for animals.

Answer

Answer: food, shelter


3. The forest keeps on ………………. and ………………. and can ……………….

Answer

Answer: growing, changing, regenerate


4. Forests protect the ………………. from erosion.

Answer

Answer: soil


5. ………………. helps forests to grow and regenerate.

Answer

Answer: Soil


6. Branchy part of a tree above the stem is known as the ………………. of the tree.

Answer

Answer: crown


7. Plants release ………………. through the process of photosynthesis.

Answer

Answer: oxygen


8. Microorganisms convert dead animal and plant tissues into a dark-coloured substance called ………………. .

Answer

Answer: humus


Choose the true and false statements from the following:

1. We get various useful products from the forests surrounding us.

Answer

Answer: True


2. Forest is a system comprising various plants, animals and microorganisms.

Answer

Answer: True


3. Forests must be cleared to make the human life safe and comfortable.

Answer

Answer: False


4. Different layers of vegetation provide food and shelter for animals, birds and insects.

Answer

Answer: True


5. Plants release carbon dioxide in the process of photosynthesis.

Answer

Answer: False


6. The various components of the forest are interdependent on one another.

Answer

Answer: True


7. In the forest there is interaction between soil, water, air, and living organisms.

Answer

Answer: True


8. Forests are the lifeline for the forest-dwelling communities.

Answer

Answer: True


9. Forests are the result of hard working of ancient people who have planted most of the forests.

Answer

Answer: False


10. Forests influence climate, water cycle and air quality.

Answer

Answer: True

Question 1.
List some animals which live in deeper areas of the forest.
Answer:
Boars, bisons, jackals, porcupines, elephants, etc., live in the deeper areas of the forest.

Question 2.
Paheli while moving in a forest observed that there was no noise pollution, though lots of heavy vehicles were passing from the nearby highway. Explain why. [NCERT Exemplar; HOTS]
Answer:
Paheli observed that there is no noise pollution in a forest even though there are lots of heavy vehicles passing from the nearby highway. It is because trees present in the forest absorb the noise.

Question 3.
Give the reason behind variations found in the forests of different regions.
Answer:
The variation in the type of plants and animals is found in different forests because of the climatic conditions of that particular area.

Question 4.
Paheli wrote a food chain in the following way:
Frog → Eagle → Insects → Grass → Snake
The chain is not in the correct order. Help her to write the food chain correctly. [NCERT Exemplar]
Answer:
The correct food chain is
Grass → Insects → Frog → Snake → Eagle

Question 5.
Are there similar kind of trees in every forests?
Answer:
No, due to different climatic conditions, there are variations in the types of trees and other plants. From forest to forest.

Question 6.
State the consequence when one food chain is disturbed in an ecosystem.
Answer:
Since, all food chains are interlinked disturbance in one food chain will affect the other food chain in a forest.

Question 7.
What is a canopy?
Answer:
The uppermost branches and leaves of tall trees act like a roof over forest ground, this is called a canopy.

Question 8.
While going inside a forest, it becomes darker. Why?
Answer:
In a forest, big trees, shrubs and other plants are found. They trap solar radiation for photosynthesis.
So, the sunlight does not reach at the forest floor, thus making it dark.

Question 9.
A bunch of seedlings were seen sprouting on a heap of animal dropping in a forest. How do you think is the seedling benefited from the animal dung? [NCERT Exemplar; HOTS]
Answer:
The seedling was being benefited from the animal dung as the decaying animal dung provided nutrients to the growing seedlings.

Question 10.
Consider the following organisms:
Grass, birds, frog, crow, tiger, vulture, toadstool, deer. Which of these
(i) can eat the dead animals
(ii) can form a three step food chain?
Answer:
(i) Crow, vulture
(ii) Grass → Deer → Tiger

Question 11.
Give names of any four birds which you expect to see in a forest. [NCERT Exemplar]
Answer:
The four birds which we expect to see in a forest are jungle crow, hornbill, myna and koel.

Question 12 .
Draw any simple food chain in a pond.
Answer:
A typical food chain in a pond is
Algae → Small fishes → Large fishes

Question 13.
Name any four useful products other than wood, which we get from forests. [NCERT Exemplar]
Answer:
Four useful products other than wood which we get from forests are gum, spices, fodder for animals and medicinal plants.

Question 14.
Deforestation may lead to floods. Why? [NCERT Exemplar]
Answer:
Deforestation leads to floods as lesser number of trees will be available due to deforestation. In the absence of trees, the soil will not hold water leading to floods.

Question 15.
All the needs of animals living in a forest are fulfilled. Justify this statement in a few sentences. [NCERT Exemplar; HOTS]
Answer:
Forest provides homae (shelter), food and water to the animals living there. Thus, all the needs of animals living in a forest are fulfilled.

Forests: Our Lifeline Class 7 Science Extra Questions Short Answer Type Questions

Question 1.
Forests are valuable resources. Explain.
Answer:
Forest products play vital role in socio-economic development. We get food (cereals, pulses, fruits), fire wood, fibre, construction material, industrial products (tannins, lubricants, dyes, resins, perfumes) and products of medicinal importance. It is also the home of diverse wildlife which maintains the ecosystem. Thus, forests are valuable resources.

Question 2.
Plants help in maintaining O2-CO2 cycle. Explain it in the light of photosynthesis and respiration.
Answer:
Photosynthesis is the process during which CO2 is used by the plants and O2 is released as a products. This O2 is used by the animals for their respiration and CO2 is released during it which is again used for photosynthesis by plants. In this way, O2-CO2 cycle is balanced by plants.

Question 3.
Forests are called green lungs. Why?
Answer:
The forests provide us oxygen to breathe. If we rapidly cutting down forests means we are cutting down the oxygen supply to us. That is why they are called green lungs.

Question 4.
Two friends shared their experiences of their vacation trip to two different forests. Do you think they would have seen the same type of plants and animals during their respective trips? Give reason. [HOTS]
Answer:
No, they would not have seen the same type of plants and animals. This is so because climatic conditions in the two forests would vary leading to variations in the types of plants and animals.

Question 5.
Write differences between decomposers and scavengers.
Answer:
Difference between decomposers and scavengers is

DecomposerScavenger
These are the microbes which break dead organic matter into simple molecules to be used by plants again.These animals eat the body of dead animals and are called cleaning agent of forests, e.g. jackal, fox, vultures, etc.

Question 6.
What would happen if forests disappear?

Question 7.
Plants are known as the producers of a food chain. Give reason.
Answer:
Plants are known as the producers of a food chain. It is because green plants (autotrophs) make their own food from carbon dioxide and water in the presence of sunlight and chlorophyll by a process called photosynthesis and provide food to all living organisms which live in the forest.

Question 8.
Life would be impossible without plants. Explain, how.
Answer:
All green plants are producers. They make food by the process of photosynthesis using water C02 and sunlight. All forms of animals depend on plants for food. So, if there no plants, no food will be there. Plants are give oxygen also during photosynthesis, and there would be no oxygen in absence of plant. These two basic needs make plants important for us and we cannot think of life without plants.

Question 9.
Y and Z are two types of organism which are found in the forests. Y eats up dead animals while Z breakdown the body of the dead animals into simpler substances.
(a) What is the general name of organism Y?
(b) Write one example of Y type organism.
(c) What is general name of organism Z?
(d) Write one example of Z type organism. (HOTS]
Answer:
(a) Scavenger
(b) Vulture
(c) Decomposers
(d) Fungi (mushroom)

Question 10.
What happens when an animal dies in the forest?
Answer:
The body of the dead animal is eaten up by scavengers like vultures, jackals, hyanas, etc.
These animals do the functions of cleaning in the forest. This also shows that nothing goes waste in the forests.

Question 11 .
Give any four factors which are responsible for the destruction of forests. [NCERT Exemplar)
Answer:
The four factors which are responsible for the destruction of forests are

  • Construction of roads.
  • Construction of buildings.
  • Industrial development.
  • Increasing demand of wood.

Question 12.
Is it possible to construct a food chain without a producer? State the reason to support your answer.
Answer:
No, in any food chain, producers are always at the beginning. It is the producer which provides food to all living organisms. In a food chain, if producer is absent, then there will be no flow of energy. So, we can say that it is not possible to construct a food chain without a producer.

Question 13.
How can a pipal sapling would have grown on a side wall of some old buildings?
Answer:
Animals disperse the seeds of certain plants with the help of their droppings. Therefore, pipal seed would have come to the wall by a bird dropping . On coming in contact with water and suitable nutrient medium, it would have grown into pipal sapling.

Question 14.
If one component of the forest is removed, what would be its affect on the ecosystem?
Answer:
Every component of forest depend on other. If we remove one, the other will be affected, e.g. if we remove top carnivores (lion/tiger) in a forest, herbivores will increase and if they increase they will end up eating all plants, so ecosystem will get disturbed.

Question 15.
State the role of scavengers in cleaning of our environment.
Answer:
Scavengers eat the dead animals and act as the cleaning agents of our environment. Some of these animals (scavengers) are vultures, crows, jackals, hyena, some insects, etc.

Question 16.
Crown is different from canopy. Explain how.
Answer:
The part of the tree with branches is known as the crown. When the crown of tall trees in the forests forms a roof-like covering over the others plants, it is known as a canopy.

Question 17.
“You conserve forest, you conserve soil”. Do you agree? Justify. [HOTS]
Answer:
Yes, forests bind soil with root and prevent soil erosion. They also maintain fertility of soil and check So, it can be said that conserving forest results in conservation of soil.

Question 18.
Deforestation can increase the earth’s temperature. Is it true? Give reason.
Answer:
Yes, if there are no tress and plants, there will be no photosynthesis. So, no CO2 of the atmosphere will be used. This will increase the level of CO2, resulting in the increase of earth’s temperature.

Question 19.
Explain how root system of plants help in the prevention of flood?
Answer:
The root system helps water to seep down in the ground. It helps to maintain the water table throughout the year. Roots of trees normally bind the soil together and stop the erosion of soil.

Question 20.
Sketch a diagram to show how plants maintain the balance between carbon dioxide and oxygen in the atmosphere?
Answer:
Forests Our Lifeline Class 7 Extra Questions Science Chapter 17 1

Forests: Our Lifeline Class 7 Science Extra Questions Long Answer Type Questions

Question 1.
People say that nothing goes waste in a forest. Can you explain how? [NCERT Exemplar; HOTS]
Answer:
Nothing goes waste in a forest because of the following reasons

  • Dry leaves and remains of dead animals are converted to a dark coloured substance called humus. This provides nutrients to the plants.
  • Dead animals become food for vultures, crows, jackals and insects.
  • Broken branches of trees are used as fuel by the people living in the vicinity of the forest.

Question 2.
“Forest is a dynamic entity, full of life and vitality”. Explain briefly. [HOTS]
Answer:
Forests harbour great variety of plants and animals. Plants provide food to herbivores. Larger number of herbivores means increased availability of food for a variety of carnivores. Wide variety of animals helps forest to regenerate.

Decomposers and scavengers are cleaning agents. So, every entity in the forest plays a key and vital role making it a dynamic living entity, full of life and vitality.

Question 3.
Write the major steps by which we can conserve the forest.
Answer:
Forests maintain balance in nature. There conservation is the need of the hour. We should take the following steps to conserve the forests

(i) Planned harvesting An efficient way to get wood from forests for our requirements is to cut only some of the trees in an area. The uncut trees prevent erosion. Fruits of these trees produce seeds so that new trees can grow. This way the forest cover is maintained.

(ii) Afforestation This is the practice of renewing a forest by planting seedlings or small trees. These days, in our country, planned afforestation is being done not only by the government but also by private organisations for commercial purposes. Selective cutting of trees in these plantations provides wood for construction and also keeps the forest cover intact.

(iii) Protection from fire Huge forest areas are destroyed by fire every year. Fire may occur due to the carelessness of people or due to lightning during a storm or by friction between dry stems and dry branches of trees.
Forest fires are controlled by spraying fire extinguishing solutions from aircrafts or by changing the direction of wind by using strong blowers.

Question 4.
Figure shows a part of a forest.
Forests Our Lifeline Class 7 Extra Questions Science Chapter 17 2
Write any three activities going on in the forest on the basis of this figure. [NCERT Exemplar]
Answer:
The three activities going on in the forest on the basis of the given figure are

  • Oxygen is given out by plant leaves.
  • Carbon dioxide is consumed by the plants to prepare their food by the process of photosynthesis.
  • Nutrients are being added to the soil by the action of decomposers.

Question 5.
Cycling of papers help in the conservation of the forests. Justify.
Answer:
The papers are made from wood pulp. We derive wood by cutting down trees. If we recycling existing quantity of paper in the market and will not let it decompose, we can stop cutting of forest trees for new raw materials required for paper making.
It takes years to grow a tree and cutting a tree takes only few minutes.
So, we should give a serious thought before cutting a single tree even and should encourage recycling of papers every where in our country and in the world.

Question 6.
Sachin lives in a village, this village is surrounded by a forest. One day he noticed that in nearby pond sedimentation is increased so much that water has become muddy, streams are drying up. There is scarcity of fuel wood. He soon realised that he has to raise the issue of forest protection from cutting down trees, etc. Soon he involved the nearby village people and made an organisation to take an initiative.
Now, answer the following questions
(a) What changes might have Sachin noticed in his area?
(b) Give the porbable reason for such changes mentioned above.
(c) What are the values shown by Sachin? [Value Based Question]
Answer:
(a) Sachin noticed the disturbance in the water cycle in his area like stream drying up. Pond water getting muddy, less availability of fuel wood, etc.
(b) Deforestation.
(c) Love for nature and environmental consciousness.

Question 7.
A snake charmer came to the society and smelled the presence of a cobra near the guardroom. The head of the society agreed to allow the man to search, catch and take away the snake with him. Little Krishi who was seeing all this disagreed. He explained the people that it might disturb the food chain in the environment. Now, answer the following questions
(a) Describe food chain.
(b) Construct a food chain involving snake at one of its level.
(c) What are the values shown by Krishi? [Value Based Question]
Answer:
(a) The sequence of living organisms in which one organism eats another is called a food chain.
Forests Our Lifeline Class 7 Extra Questions Science Chapter 17 3
(c) Scientific attitude, obligation to maintain the ecosystem of nature.

 

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CHAPTER – 16 Water: A Precious Resource | CLASS 7TH | NCERT SCIENCE IMPORTANT QUESTIONS & MCQS | EDUGROWN

SCIENCE IMPORTANT QUESTIONS & MCQS FOR CLASS 7th

Get Chapter Wise MCQ Questions for Class 7 Science with Answers prepared here according to the latest CBSE syllabus and NCERT curriculum. Students can practice CBSE Class 7 Science MCQs Multiple Choice Questions with Answers to score good marks in the examination.  Students can also visit the most accurate and elaborate NCERT Solutions for Class 7Science. Every question of the textbook has been answered here.

Chapter -16 Water: A Precious Resource

Question 1.
On which day the world water day is celebrated?
(a) 23rd March
(b) 22nd March
(c) 21st March
(d) None of these

Answer

Answer: (b) 22nd March


Question 2.
Which year was observed as International Year of Fresh Water?
(a) 2003
(b) 2004
(c) 2006
(d) 2002

Answer

Answer: (a) 2003


Question 3.
Which of the following does not show water shortage?
(a) Taps running dry
(b) Long queue for getting water
(c) Marches and protests for demand of water
(d) A family gets three buckets of water per person per day

Answer

Answer: (d) A family gets three buckets of water per person per day


Question 4.
Seas and oceans are full of water on earth. However, a very small percentage of water present on earth is available for us. This percentage is roughly
(a) 0.006%
(b) 0.06%
(c) 0.6%
(d) 6%

Answer

Answer: (a) 0.006%


Question 5.
Which of the following is a way to use water economically?
(a) construction of bawris
(b) Rainwater harvesting
(c) Drip irrigation
(d) Infiltration

Answer

Answer: (c) Drip irrigation


Question 6.
On which of the following day is World Water Day observed
(a) 22 March
(b) 14 November
(c) 2 October
(d) 21 December

Answer

Answer: (a) 22 March


Question 7.
The amount of water recommended by the United Nations for drinking, washing, cooking and maintaining proper hygiene per person per day is a minimum of
(a) 5 litres
(b) 15 litres
(c) 30 litres
(d) 50 litres

Answer

Answer: (d) 50 litres


Question 8.
“Every Drop Counts” is a slogan related to
(a) counting of drops of any liquid
(b) counting of water drops
(c) importance of water
(d) importance of counting

Answer

Answer: (c) importance of water


Question 9.
Water cycle does not involve which of the following?
(a) Evaporation
(b) Condensation
(c) Formation of clouds
(d) Rainwater harvesting

Answer

Answer: (d) Rainwater harvesting


Question 10.
Which of the following inhibits the seepage of rainwater into ground?
(a) A pukka floor
(b) playground
(c) Grass lawn
(d) Forest land

Answer

Answer: (a) A pukka floor


Match the following:

Column AColumn B
(i) Solid(а) Water under water table
(ii) Liquid(b) Traditional way of collecting water
(iii) Gas(c) Water between the hard rocks
(iv) Groundwater(d) Ice, snow
(v) Aquifer(e) Water in ponds, rivers, oceans
(vi) Bawri(f) Water vapour
Answer

Answer:

Column AColumn B
(i) Solid(d) Ice, snow
(ii) Liquid(e) Water in ponds, rivers, oceans
(iii) Gas(f) Water vapour
(iv) Groundwater(а) Water under water table
(v) Aquifer(c) Water between the hard rocks
(vi) Bawri(b) Traditional way of collecting water

Fill in the blanks:

1. Water on the earth has been maintained for millions of years by various processes which make ………………..

Answer

Answer: water cycle


2. the ……………….. form of water is the water vapour.

Answer

Answer: gaseous


3. The ……………….. in the soil indicates the presence of under groundwater.

Answer

Answer: moisture


4. The process of ……………….. of water into the ground is called infiltration.

Answer

Answer: seeping


5. Water in the ……………….. can be easily pumped out with the help of tube wells or handpumps.

Answer

Answer: aquifer


6. ……………….. was the traditional way of collecting water.

Answer

Answer: Bawri


Choose the true and false statements from the following:

1. The water that is fit for use is called fresh water.

Answer

Answer: True


2. The water table varies from place to place and it may even change at a given place.

Answer

Answer: True


3. The water found above the water table is called groundwater.

Answer

Answer: False


4. Drip irrigation has a disadvantage that it is associated with huge loss of water.

Answer

Answer: False


5. Water is essential for all living beings.

Answer

Answer: True


6. Plants wilt and ultimately dry up if they are not watered for a few days.

Answer

Answer: True

Question 1.
Suggest one traditional way of storing water from ancient time.
Answer:
In ancient times, people used to make Bawris to store water.

Question 2.
What is the source of water in each of the following? [NCERT Exemplar]
(a) Wells
(b) Ground
(c) Atmosphere
Answer:
(a) The source of water in wells is groundwater.
(b) The source of water on ground is rain.
(c) The source of water in atmosphere is evaporation.

Question 3.
The earthTooks blue from space. Explain why? [HOTS]
Answer:
The major surface area (71%) of the earth is covered with water. This imparts blue colour to the earth.

Question 4.
Some slogans has been given for the conservation of water. What does the slogan ‘Jal hai to kal hai’ means?
Answer:
This means if you have water, you can think of future, i.e. no life is possible without water.

Question 5.
Reservoir of dam helps us to manage water. How?
Answer:
The reservoir of dam or river can release water at our will. We can divert the flow of water at desired places where it is really needed and we can manage water resource effectively.

Question 6.
The excessive use of water leads to a severe problem. Write the problem.
Answer:
The excessive use of water leads to water scarcity in an area.

Question 7.
How much of the earth’s surface is covered with water?
Answer:
About two-third of the earth’s surface is covered with water.

Question 8.
Mention the year which is celebrated as international year of freshwater?
Answer:
The year 2003 was celebrated as International year of freshwater.

Question 9.
State the consequences, if plants do not get enough water.
Answer:
The plants will wilt and ultimately dry up in lack of water.

Question 10.
Mention the source of groundwater.
Answer:
Rainwater and water from the other sources like rivers, ponds, etc are the source of groundwater.

Question 11.
From where do the workers get water for construction?
Answer:
Workers get water from the underground water.

Question 12.
Can we keep on drawing water from under the ground? How will it affect the water table?
Answer:
No, we cannot keep on drawing water.
It causes the depletion of water table.

Question 13.
State the percentage of actual amount of water available for human use.
Answer:
The actual amount of water available for human use is very little, i.e. approx 0.0006 % of all water found on the earth.

Question 14.
If wells dug to get groundwater, then it dry up after sometime, what initiative should be taken to get water from it again? [HOTS]
Answer:
In the above condition, the groundwater get recharged through the process of infiltration. It replenishes the groundwater.

Question 15.
Water circulates through the water cycle in the three forms. Name them.
Answer:
Water circulates through the water cycle in the three forms, i.e. solid, liquid and gas.

Question 16.
As our population increases, we need more water for drinking, washing and other purposes. Does this affect the water table? Explain.
Answer:
Yes, rising population leads to an increase in consumption and at the same time, a decrease in the seepage of water into the . ground leads to the depletion of water table.

Question 17.
The substance Wis necessary for the normal growth and development of all types of plants and animals. An acute scarcity of substance Whas an ill effect on plants which can hinder the natural process Xin plants causing a severe shortage of /leading to famine. It may also lead the shortage of Zwhich is essential for breathing and respiration. What could W, X, Yand Zbe? [HOTS]
Answer:
W- Water, X- Photosynthesis
Y-Food, Z-Oxygen

Water: A Precious Resource Class 7 Science Extra Questions Short Answer Type Questions

Question 1.
Explain how the traditional use of groundwater is different from the present use.
Answer:
Traditionally in ancient times, people made bawris to collect rainwater in the old buildings. We still use these structures and are reviving them to harness rainwater.

Question 2.
Planting trees help groundwater conservation. Explain how.
Answer:
Plants lose water in the form of water vapour by the process of transpiration. So, forests contribute a lot of water vapours formation which make clouds.
Thus, plants help to revive water cycle.

Question 3.
List the reasons for lowering of water table in cities.
Answer:
Water drawn from underground water gets replenished by seepage of rainwater. The water table does not get affected as long as we draw the same amount of water as is replenished by natural resources like rain.

However, there are number of factors which cause depletion of water table at a very fast rate which is really a matter of concern for everyone of us. Increase in population, industrial and agricultural activities are some common factors affecting water table. Scanty rainfall, deforestation and decrease in the effective area for seepage of water may also deplete the water table.

Question 4.
Complete the given table. (NCERT Exemplar]

 Form of waterProcess by which formedLocation where found
(a)Liquid  
(b)Solid  
(c)Gaseous  

Answer:
The complete table is given below:

 Form of waterProcess by which formedLocation where found
(a)LiquidCondensation and meltingWaterbodies like rivers, lakes, etc.
(b)SolidFreezingCold regions like high mountains, poles, etc.
(c)GaseousEvaporationAtmosphere

Question 5.
Place the following statements in a proper order to form a meaningful paragraph.
(a) Which in turn decreases the seepage of rainwater into the ground.
(b) This decreases the open areas like parks and playgrounds.
(c) Increasing population create demand for construction of houses, shops, offices, roads and pavements.
(d) This results in depletion of water table and creates scarcity of more water. INCERT Exemplar]
Answer:
Increasing population create demand for construction of houses, shops, offices, roads and pavements (c). This decreases the open areas like parks and playgrounds (b) which inturn decreases the seepage of rainwater into the ground (a). This results in depletion of water table and creates scarcity of more water (d).

Question 6.
Given below are three states of water in a beaker. These states are inter-convertible. Name the process forward and backforth labelled A, B, C, D, which cause these conversions. [HOTS]
Water A Precious Resource Class 7 Extra Questions Science Chapter 16 1
Answer:
A-Melting, 6-Boiling, C- Freezing,
D- Condensation

Question 7.
The water bearing layer of the earth called P is made up of two components O and R, in which R water collect under the ground. The top level of layer Pis called S. When too many tubewells are used in an area, the level of S in that area goes down. What are P, Q, R and S? [HOTS]
Answer:
P- Aquifer, Q- Soil, R- Permeable rocks,
S -Water table

Question 8.
How can you observe the three forms of water (a) in nature and (b) at home? INCERT Exemplar]
Answer:
The three forms of water

  • in nature are snow (solid), water (liquid) and water vapour (gas).
  • at home are ice (solid), water (liquid) and steam (gas).

Question 9.
Name some industries familiar to you. Make a list of the products obtained from these and used in our daily life. Discuss how the growing industrial activity is responsible for depletion of water table?
Answer:
Following industries and their products pollute the water:

  • Leather industries, e.g. shoes and other products.
  • Chemical factories, e.g. fertilisers, different insect repellant sprays, etc.
  • Petrochemical industries, e.g. petroleum and different fuels.
  • Oil industries.

All the above industries release pollutants such as asbestos, lead, mercury, nitrates, sulphur, etc in different rivers, lakes and ponds which are polluting the water and hence is responsible for depletion of water table.

Question 10.
Mention three causes of water scarcity in our country.
Answer:
The three causes of water scarcity in our country are

  • Rapid urbanisation.
  • Increased number of industries.
  • Population explosion.

Question 11.
Certain pattern of the rainfall in our country leads to scarcity of water. Explain that pattern. Which part of the country gets rainfall twice a year?
Answer:
We face shortage of water mainly because water is not evenly distributed by the nature on the earth. Some places such as North East India get so much rains, so that it gets flooded almost every year. On the other hand, Thar desert in Rajasthan may get rains rarely in the monsoon season. This uneven pattern of rains causes water scarcity in India at some places.

Question 12.
A number of problems can be faced due to shortage of water. List some of them.
Answer:
The number of problems that can be faced due to shortage of water are as follows

  • Less amount of pure drinking water will be available.
  • Lack of equal distribution of water.
  • Drought.

Question 13.
From where do the following usually get water? In which form is water present in them?
(a) Clouds
(b) Plants
(c) Mountain tops
(d) Aquifer
(e) Animals (NCERT Exemplar]
Answer:

 Source of waterForm of water
CloudsLandLiquid form (droplet of water)
PlantsSoilLiquid form
Mountain topsAtmosphereSolid form
AquiferRainUnderground water
AnimalsWaterbodiesLiquid

Question 14.
Some definitions are given which can be corrected by changing one word. Correct them.
(a) Aquifer is groundwater stored between layers of hard rock above the water table.
(b) The process of evaporation of water in the ground is called infiltration.
(c) The evaporation of water from oceans and its arrival back into oceans is called vapour cycle. (NCERT Exemplar]
Answer:
(a) Aquifer is groundwater stored between layers of hard rock below the water table.
(b) The process of seeping of water in the ground is called infiltration.
(c) The evaporation of water from oceans and its arrival back into oceans is called water cycle.

Question 15.
Deforestation can be considered as a reason for depletion of the water table. Comment.
Answer:
Large scale deforestation has occurred to accommodate the growing population, to grow food for them and to provide space for industries. Vegetation slows down the flow of rainwater on land and increases the absorption of water by the soil.
Cutting down of trees and destroying vegetation, therefore interferes with the natural process by which seeping takes place and the groundwater is recharged.
It finally results in the depletion of the water table.

Question 16.
Give the main causes of water scarcity in our country.
Answer:
The main causes of water scarcity in our country are

  • Rapid urbanisation.
  • Increased number of industries.
  • Population explosion.

Water: A Precious Resource Class 7 Science Extra Questions Long Answer Type Questions

Question 1.
Sachin lives in an area where on and off water scarcity is there. He gave a thought to the problem and planned to get a solution. He decided to harvest rainwater in his village. He made efforts to convince the people of his area, built some drainage system and water tanks where rainwater could be collected.
(a) Name few structures he might have built.
(b) Name the process of water cycle, Sachin will use for harvesting water.
(c) Write the methods, Sachin will tell the people to use water wisely. (Value Based Question]
Answer:
(a) Sachin has build up cemented drainage channels in the elevated area and tanks where these channels will collect water.
(b) Sachin is planning to harvest rainwater.
(c) Sachin will educate people to use water judicially in the following way
(i) Use mug for brushing, shaving and bathing.
(ii) Water plants with drip irrigation.
(iii) Use and reuse water in home activities.

Question 2.
Two figures ‘a’ and ‘b’ are given below. Both are revealing two different human activities which are the cause of depletion of water table. Identify the two acts and explain how are these causing the depletion of water resource. [HOTS]
Water A Precious Resource Class 7 Extra Questions Science Chapter 16 2
Answer:
(a) Large scale construction
(b) Deforestation
Large scale construction It is main cause of water table lowering because it utilises large amount of water at the time of construction. Most of the time, it is digged water table.

Secondary, when ground surface becomes cemented. It does not allow seepage of rainwater into deeper layers, so rainwater goes waste as run off water and cannot replenish the water table of that particular place.

Deforestation Plants transfer huge amount of water in the form of water vapours. So, when forests are cut down, we interrupt in the process of water cycle of that area. So, no rain occurs at that place and it gradually turns into desert area.

Question 3.
Shishir returned from school and found his mother busy in the kitchen. He noticed that she is making his favourite dosa. Shishir rushed to his mother as he was feeling hungry and found that the tap in the kitchen was leaking. He told his mother to replace it as leaking taps lead to the wastage of water. His mother smiled and ensured him to do the same.
(a) What is water management?
(b) Why should we save water?
(c) What values are shown by Shishir? [Value Based Question]
Answer:
(a) Minimum wastage of water is called water management.
(b) We should save water to prevent water crisis.
(c) Shishir is sincere, responsible and has capability of applying knowledge practically.

Question 4.
What is groundwater? What are the sources of water which are fed by groundwater?
Answer:
The wells, tubewells and handpumps are main sources of water for many people. The water in these sources is the groundwater. It is upper level of underground water which occupies all the spaces in the soil and rocks and form a water table as shown in the figure below:
Water A Precious Resource Class 7 Extra Questions Science Chapter 16 3
The upper limit of groundwater is called water table. It represents the depth of water filled area at a given place. The water table rises and falls depending upon the amount of rainwater that seeps into the groundwater and how much groundwater is drawn out for irrigation and industry. The seeping down of rainwater into the groundwater is called infiltration. The groundwater, thus gets recharged by this process.

At some places, the groundwater is stored between layers of hard rock below the water table. This is aquifer which contains the groundwater usable by tubewells and handpumps. These sources however, have limited sources of water and may get exhausted if used excessively.

Question 5.
Water is very precious for all the living beings.
What will happen in future, if we do not save water now? [NCERT Exemplar]
Answer:
Water is needed for various life activities. If we continue the misuse of water and do not conserve it, the groundwater level will be depleted. This may result into various consequences like

  • Lowering of the water table Excessive pumping can lower the groundwater table.
  • Reduced surface water supply Groundwater and surface water are connected. When groundwater is overused, the lakes, streams and rivers connected to groundwater, can also have little supply.
  • Loss of plants from land We fully depend on the plants for food directly or indirectly. Plants need water to prepare their food. If there will be scarcity of water on earth, the plants will be unable to prepare their food. This inturn will lead to the end of the life because world without plants means no food, no oxygen, not enough rain and other innumerable problems.
    Therefore, it is true that water is a precious resource.

Question 6.
All the rain that falls over an area is not utilised. Do you agree? Explain.
Answer:
Precipitation (rain) is a natural process and is a part of natural water cycle. It replenishes all the natural resources of water like ponds, lakes, river and finally oceans and seas too.
When we say utilisation of rainwater, we mean that rain in a particular area.
Yes, it is not properly utilised as most of the water is run off as surface water to the rivers and goes to oceans.
We can harness/harvest this water to local waterbodies like ponds, lakes and groundwater by proper planning as it is being done in some districts of Rajasthan successfully.

Read More

CHAPTER – 15 Light | CLASS 7TH | NCERT SCIENCE IMPORTANT QUESTIONS & MCQS | EDUGROWN

SCIENCE IMPORTANT QUESTIONS & MCQS FOR CLASS 7th

Get Chapter Wise MCQ Questions for Class 7 Science with Answers prepared here according to the latest CBSE syllabus and NCERT curriculum. Students can practice CBSE Class 7 Science MCQs Multiple Choice Questions with Answers to score good marks in the examination.  Students can also visit the most accurate and elaborate NCERT Solutions for Class 7Science. Every question of the textbook has been answered here.

Chapter - 15 Light

Question 1.
The path of the light is
(a) always a straight line
(b) a curved line
(c) a zig-zag line
(d) depends on the medium

Answer

Answer: (a) always a straight line


Question 2.
Which one shows lateral inversion?
(a) Plane mirror
(b) Convex mirror
(c) Concave mirror
(d) All of these

Answer

Answer: (a) Plane mirror


Question 3.
Image formed by a plane mirror is
(a) virtual and erect
(b) real and erect
(c) virtual and inverted
(d) real and inverted

Answer

Answer: (a) virtual and erect


Question 4.
Boojho and Paheli were given one mirror each by their teacher. Boojho found his image to be erect and of the same size whereas Paheli found her image erect and smaller in size. This means that the mirrors of Boojho and Paheli are, respectively
(a) plane mirror and concave mirror
(b) concave mirror and convex mirror
(c) plane mirror and convex mirror
(d) convex mirror and plane mirror

Answer

Answer: (c) plane mirror and convex mirror


Question 5.
Which of the following can be used to form a real image?
(a) Concave mirror only
(b) Plane mirror only
(c) Convex mirror only
(d) Both concave and convex mirrors

Answer

Answer: (a) Concave mirror only


Question 6.
If an object is placed at a distance of 0.5 m in front of a plane mirror, the distance between the object and the image formed by the mirror will be
(a) 2 m
(b) 1 m
(c) 0.5 m
(d) 0.25 m

Answer

Answer: (b) 1 m


Question 7.
You are provided with a concave mirror, a convex mirror, a concave lens and a convex lens. To obtain an enlarged image of an object you can use either
(a) concave mirror or convex mirror
(b) concave mirror or convex lens
(c) concave mirror or concave lens
(d) concave lens or convex lens

Answer

Answer: (b) concave mirror or convex lens


Question 8.
An erect and enlarged image can be formed by
(a) only a convex mirror
(b) only a concave mirror
(c) only a plane mirror
(d) both convex and concave mirror

Answer

Answer: (b) only a concave mirror


Question 9.
You are provided with a convex mirror, a concave mirror, a convex lens and a concave lens. You can get an inverted image from
(a) both concave lens and convex lens
(b) both concave mirror and convex mirror
(c) both convex mirror and convex lens
(d) both convex mirror and concave lens

Answer

Answer: (c) both convex mirror and convex lens


Question 10.
An image formed by a lens is erect. Such an image could be formed by a
(a) convex lens provided the image is smaller than object.


(b) concave lens provided the image is smaller than object.


(c) concave lens provided the image is larger than object.
(d) concave lens provided the image is of the same size.

Answer

Answer: (b) concave lens provided the image is smaller than object.


Match the following:

Column AColumn B
(i) Concave lens(a) Lateral inversion
(ii) Always virtual image(b) Reflecting surface is bulged out
(iii) Changing position of image(c) Concave mirror
(iv) Wax paper(d) Seven colours
(v) Image obtained on screen(e) Real image
(vi) Convex mirror(f) Translucent
(vii) Used by dentists(g) Thinner in the middle
(viii) White light composed(h) Concave lens
Answer

Answer:

Column AColumn B
(i) Concave lens(g) Thinner in the middle
(ii) Always virtual image(h) Concave lens
(iii) Changing position of image(a) Lateral inversion
(iv) Wax paper(f) Translucent
(v) Image obtained on screen(e) Real image
(vi) Convex mirror(b) Reflecting surface is bulged out
(vii) Used by dentists(c) Concave mirror
(viii) White light composed(d) Seven colours

Fill in the blanks:

1. Uneven surfaces show ………………….. reflection.

Answer

Answer: irregular


2. Incident ray, the reflected ray ………………….. and lie in the same …………………..

Answer

Answer: normal,plane


3. Laws of ………………….. is applicable in playing back shots in the carroms.

Answer

Answer: reflection


4. Changing of right side to left is called …………………..

Answer

Answer: lateral inversion


5. The inner surface of a steel spoon acts as a ………………….. mirror.

Answer

Answer: concave


6. The outer surface of a flat steel plate acts as a ………………….. mirror.

Answer

Answer: plane


7. The outer shining surface of a round bottom steel bowl acts as a ………………….. mirror.

Answer

Answer: convex


8. The inner surface of the reflector of a torch acts as a ………………….. mirror.

Answer

Answer: concave


Choose the true and false statements from the following:

1. Concave mirror is converging in nature.

Answer

Answer: True


2. Convex mirror is diverging in nature.

Answer

Answer: True


3. Plane mirror forms virtual image.

Answer

Answer: True


4. Concave mirror has a virtual focus.

Answer

Answer: False


5. Spherical mirrors do not obey laws of reflection.

Answer

Answer: False


6. During lateral inversion, the image becomes inverted.

Answer

Answer: False


7. Angle between incident ray and reflected ray is double that of the angle of incidence.

Answer

Answer: True

Question 1.
Briefly mention whether mirror change the direction of light.
Answer:
Yes, when a ray of light is incident on the mirror surface, then the mirror changes the direction of light.

Question 2.
The image formed by a lens is always virtual, erect and smaller in size for an object kept at different positions in front of it. Identify the nature of the lens. (NCERT Exemplar]
Answer:
Such types of lenses which always form virtual, erect and smaller image in spite of the different positions of an object are called concave lens.

Question 3.
Observe the given figures carefully.
Light Class 7 Extra Questions Science Chapter 15 1
The given figures show the path of light through lenses of two different types represented by rectangular boxes A and B. What is the nature of lenses A and B ? [NCERT Examplar]
Answer:
Since, in first case light rays are converging towards a point, so the lens A will be convex and in case of lens 8, light rays diverge or spread out. So, the lens will be concave lens.

Question 4.
Name the colours include in the composition of sunlight.
Answer:
As we know that sunlight consists of mixture of seven colours (i.e. VIBGYOR).

Question 5.
In the formation of a rainbow, what acts as tiny prisms?
Answer:
In the formation of a rainbow, the raindrops suspended in the atmosphere acts as tiny prism.

Question 6.
Briefly mention what makes things visible to us.
Answer:
When a light ray falls on an object, then reflected light ray which comes from the object when A falls on our eys, allows us to see things around us.

Question 7.
Name the type of lens which diverges a beam of parallel rays of light.
Answer:
The lens which diverges a beam of parallel rays of light is a concave lens.

Question 8.
Is the image formed by a plane mirror is always upright?
Answer:
Yes, the image formed by the plane mirror is always upright.

Question 9.
Explain why are concave and convex mirrors called spherical mirrors.
Answer:
Concave and convex mirrors are the parts of sphere whose one side is polished or silvered. So, they are called spherical mirrors.

Question 10.
Is it possible to obtain the image on the screen when the candle is too closed to the concave mirror?
Answer:
No, when the candle is too closed to the concave mirror.

Question 11.
Can you get a real image at any distance of the object from the convex mirror?
Answer:
No, we cannot get a real image for any position of an object from the mirror because convex mirror always forms virtual, erect and diminished image in spite of the position of object.

Question 12.
Can you name the mirrors used as side mirrors in scooters?
Answer:
Yes, in the side mirror of scooters, convex mirror is used to have a wider field of view of the traffic.

Question 13.
Explain why concave mirror is known as a converging mirror.
Answer:
Concave mirror is known as a converging mirror because it converges a beam of parallel rays of light (reflecting from it) at one point.

Question 14.
Name the phenomenon that is involved in the formation of image of an object by a concave mirror.
Answer:
Reflection of light is the name of a phenomenon which is involved in the formation of image of an object by a concave mirror.

Question 15.
Mention the type of image formed on a cinema screen.
Answer:
Real image is an image which is formed on a cinema screen.

Question 16.
As we know that an image is formed by the actual intersection of rays and can be obtained on the screen. So, state whether it is real or virtual image.
Answer:
Since, after the actual intersection of rays, the image obtained on the screen is always real image.

Question 17.
State in brief about the term lens.
Answer:
A transparent material which is bounded by both or one spherical surface is known as a lens.

Question 18.
Name the phenomenon that is involved in the formation of image of an object by a convex lens.
Answer:
Refraction of light is the name of a phenomenon which is involved in the formation of image of an object by a convex lens.

Question 19.
Give the form of energy that produces the sensation of vision.
Answer:
Light energy is the form of energy which produces the sensation of vision.

Question 20.
What type of mirror is used as a side mirror in a scooter? Why is this type of mirror chosen? [NCERT Exemplar]
Answer:
Convex mirror is used as a side mirror in a scooter because it can form images of objects spread over a larger area.
So, this helps the driver to view the traffic over a large area behind them.

Question 21.
Briefly mention how many types of lens are there. Explain each of them.
Answer:
There are two types of lenses.
The lens which is thinner in the middle than at the edges is called a concave lens while the lens
which is thicker in the middle than at the edges is called a convex lens.

Question 22.
Consider if one half of a convex lens is covered with a black paper, then state whether this lens produces a complete image of the object.
Answer:
If one half of a convex lens is covered with a black paper, then yes, the convex lens will produce the complete image of the object.

Question 23.
Briefly tell that how many reflected rays can be obtained from a single incident ray in respect of a plane mirror.
Answer:
For a single incident ray, there will be only one reflected ray that can be obtained in respect of a plane mirror.

Question 24.
State in brief what we can demonstrate by rotating Newton’s colour disc very fastly.
Answer:
By rotating Newton’s colour disc, we can demonstrate that when seven colours are mixed together, then a white colour is formed.

Question 25.
Mention the name of lens whioh can converge the sun’s rays to a point and burn a hole in the piece of paper. (HOTS]
Answer:
Convex lens is a lens which can converge the sun’s rays to a point and burn a hole in the piece of paper.

Question 26.
An erect and enlarged image of an object is formed on a screen. Explain how this could be possible.
Answer:
An erect and enlarged image of an object is formed only by the concave mirror or convex lens when object is inverted and placed between F and 2F.

Light Class 7 Science Extra Questions Short Answer Type Questions

Question 1.
The distance between an object and a convex lens is changing. It is noticed that the size of the image formed on a screen is decreasing. Is the object moving in a direction towards the lens or away from it? (NCERT Examplar; HOTS]
Answer:
In case of convex lens, when we move the object far away from the lens, the size of image decreases and ultimately, when object is at infinity, it will form a point image at focus.

Question 2.
Two different types of lenses are placed on a sheet of newspaper. How will you identify them without touching? [HOTS]
Answer:
On identifying the letters of newspaper, we can differentiate the two types of lenses.
If image is large or magnified, then the lens is a convex lens and if the image is smaller or diminished in size for all the positions of object, then the lens is concave .

Question 3.
Briefly state the characteristics of image formed by a plane mirror.
Answer:
Characteristics of the Images Formed by a Plane Mirror
Now, we will describe the various characteristics of the images formed in a plane mirror by taking the example of the image of the candle.

  • When we see the mirror, the image of candle appears to be formed behind the mirror.
  • Now, pW a vertical screen behind the plane mirror (where the image of candle appears to be situated), then we will notice that the image of candle cannot be formed on the screen. Even if the screen is placed in front of the plane mirror, then the image of candle cannot be formed on the screen. Since, the image of candle formed in the plane mirror cannot be formed on a screen, which means that the image of candle in the plane mirror is a virtual image.
  • If we see the figure, then we will find that the length and breadth of the image of the candle and its flame to be the same as that of the original candle and its flame. The image of candle in the plane mirror is of the same size as the original candle.
  • Also if we see the figure, then we will find that the candle has a flame at the top and the image of candle also has a flame at the top. So, the top of candle remains at the top in the image. In the same way, the bottom of candle remains at the bottom in an image. Such an image is called an erect image (or upright image). Therefore, the image formed by a plane mirror is erect.

Question 4.
The side mirror of a scooter got broken. The mechanic replaced it with a plane mirror. Mention any inconvenience that the driver of the scooter will face while using it. [NCERT Examplar; HOTS]
Answer:
As we know that the side mirror of a scooter must be of convex mirror so that we can view a wide range of traffic spread over a large area. But if plane mirror is used, we are not able to see large area of traffic which may be difficult for driving vehicle and can cause accident.

Question 5.
We need a shiny surface for reflection. Explain why.
Answer:
Since, the extent of reflection depends upon the shine and smoothness of the surface. So, greater the shining and smoothness of the surface, greater will be the reflection. So, this is a reason why we require a shiny surface for reflection.

Question 6.
Differentiate between a plane mirror, concave mirror and a convex mirror without touching them.
Answer:
These mirrors can be differentiated by bringing our face close to each mirror turn by turn. Since, a plane mirror will produce an image of the same size as our face while a concave mirror will produce a magnified image and our face will look much bigger and on other sides, a convex mirror will produce a diminished image and our face will look much smaller like a small child.

Question 7.
The concave reflecting surface of a torch got rusted. What effect would this have on the beam of light from the torch? [NCERT Exemplar]
Answer:
If the reflecting surface of a torch got rusted, it produces diffused light with lower intensity and the objects are not clearly visible in this diffused and lower intensity of light.

Question 8.
Mention the type of image
(a) which can be formed on the screen.
(b) which cannot be formed on the screen.
Answer:
(a) The image which can be formed on the screen is real image.
(b) The image which cannot be formed on the screen is virtual image.

Question 9.
Mention any two letters of English alphabet whose image formed in a plane mirror appears exactly similar to the letters.
Answer:
Since, image formed by the plane mirror shows lateral inversion, i.e. left seems to right or vice-versa. But in the case of alphabets A and H, these letters show the same image in the plane mirror.

Question 10.
A shopkeeper wanted to fix a mirror which will give a maximum view of his shop. What type of mirror should he use? Give reason.
[NCERT Exemplar; HOTS]
Answer:
If a shopkeeper wanted to fix a mirror which will give him maximum view of his shop, he should use convex mirror.
In case of convex mirror, it will give a wider field of view, i.e. it can collect light from a large area spread over them.

Question 11.
State the correct sequence (1-7) of colours in the spectrum formed by the prisms A and B shown in the figure.
Light Class 7 Extra Questions Science Chapter 15 2
Answer:
When a white light is passed through a prism, it disperses into its seven constituent colours.
Light Class 7 Extra Questions Science Chapter 15 3

Question 12.
Suppose we wish to obtain the real image of a distant tree. Explain two possible ways in which we can do it. [NCERT Exemplar]
Answer:

  • In first case, we will use a concave mirror, as we know that concave mirror can form real image, i.e. image on screen. The image of distant tree will be at focus in case of concave mirror.
  • In second case, we can use a convex lens as it forms real image of a distant object at focus, i. e. image of distant tree in case of convex lens will be formed at focus.

Question 13.
Explain the term lateral inversion.
Answer:
When an image is formed by the mirror in such a way that the left side of image is object’s right side and right side of image is object’s left side. So, this process of change in the sides of the object as well as of image is known as lateral inversion.

Question 14.
State the characteristics of images formed by a concave mirror.
Answer:
The characteristics of image formed by a concave mirror are:

  • The image formed by a concave mirror is not always the same size as the object. It can be either larger or smaller depending on the distance of the object to the mirror.
  • The image formed by a concave mirror is inverted when the object is kept far from the mirror. So, when it is brought very close to the concave mirror, then an erect and enlarged image is formed.

Question 15.
Boojho made light from a laser torch to fall on a prism. Will he be able to observe a band of seven colours? Explain with a reason. [NCERT Exemplar; HOTS]
Answer:
No, he will not observe band of seven colours because laser light consists of monochromatic light of single colour.
But seven colours of bands are only observed, when a white light is passed through a prism and dispersion takes place.

Question 16.
Briefly explain why in ambulance words are written laterally inverted. [HOTS]
Answer:
In case of mirror, the image formed by it is laterally inverted, i.e. left seems to be right and right seems to be left. So, in ambulance there is emergency for patients to reach hospital and by viewing in rear mirror, it can be easily identified of a vehicle and everyone give him a way.

Question 17.
Assume, a person is standing in front of a plane mirror. The distance between the mirror and his image is 6 m. If the person moves 2 m towards the plane mirror, what would be the distance between the person and his image? [HOTS]
Answer:
Since, the image is 6m away from the plane mirror. So, it means that the object is also 6m away from the mirror.
Light Class 7 Extra Questions Science Chapter 15 4
[Because OP = PI]
So, when the person moves 2 m towards the plane mirror, then the distance between the person and the plane mirror will be equal to (6 m – 2 m) = 4 m, this means that distance between the image and the mirror will be 4m.
Light Class 7 Extra Questions Science Chapter 15 5
The distance between the person and his image = PO’+ PI’= 4 + 4 = 8m

Light Class 7 Science Extra Questions Long Answer Type Questions

Question 1.
Explain with the help of an activity that when seven colours are mixed together, then white colour is formed.
Answer:
Firstly, take a circular cardboard disc of about 10 cm diameter, then divide this disc into seven equal segments and paint the seven colours of white light (red, orange, yellow, green, blue, indigo and violet) on these segments (as shown in figure given ). Instead of painting the segments, we can also paste seven coloured papers on these segments. So, this disc painted with the seven colours of spectrum is called Newton’s disc. Now, make a small hole at the centre of the disc.
Light Class 7 Extra Questions Science Chapter 15 6
Fix the disc loosely on the tip of a refill of a ball pen. Be confirm that the disc can rotate freely. Now, rotate the disc quickly in day light. So, when the disc is rotated very fast, then all the seven colours mix together due to which the disc appears to be white (see figure). Therefore, the rapid rotation of Newton’s colour disc tells us that mixing of seven colours of the spectrum can give us white light.

Question 2.
It was observed that when the distance between an object and a lens decreases, the size of the image increases. What is the nature of this lens? If you keep on decreasing the distance between the object and the lens, will you still able to obtain the image on the screen? Explain. [NCERT Exemplar; HOTS]
Answer:
On decreasing the distance between the object and lens, the size of the image increases, the nature of the lens will be convex type.
If the distance between object and lens is less than the focus of the lens, then it forms a virtual image and this image cannot be obtained on a screen but formed on the same side of the object.

Question 3.
Give the definition dispersion of light. Also, explain why does it take place? Draw a diagram to show the dispersion of white light by a glass prism.
Answer:
In the year 1665, Newton discovered by his experiments with glass prisms that white light (like sunlight) consists of a mixture of lights of seven colours. Newton found that if a beam of white light is passed through a glass prism, then the white light splits to form a band of seven colours on a white screen . The band of seven colours formed on a white screen, when a beam of white light is passed through a glass prism, is known as spectrum of white light. The seven colours of the spectrum are Red, Orange, Yellow, Green, Blue, Indigo and Violet .
Light Class 7 Extra Questions Science Chapter 15 7
So, dispersion of light is phenomenon of splitting up of white light into seven colours on passing through a transparent medium like a glass prism. The formation of spectrum of seven colours indicates that white light is a mixture of seven colours. White light can be sunlight. So, now we can say that the sunlight consists of seven colours.
We can mix these colours to get white light. This can be done by using Newton’s disc, let us try this.

Question 4.
You are given three mirrors of different types.
How will you identify each one of them? [NCERT Exemplar]
Answer:
We can identify the mirrors by forming image of an object.

  • Plane mirror In case of plane mirror, image will be virtual, erect and of same size as that of object.
  • Concave mirror In case of concave mirror, image may be real, virtual and magnified or diminished.
  • Convex mirror In case of convex mirror, image formed will always be virtual, erect and diminished.

Question 5.
Namit was driving a car and suddenly became aware of a loud sound coming from behind. He looked through his rear view mirror and saw an ambulance. He recalled reading that such emergency vehicles often have their name written in the mirror (AMBULANCE) or writing, i. e. Light Class 7 Extra Questions Science Chapter 15 8
He quickly made way for the ambulance, murmuring a quick prayer for the speedy recovery of the patient inside the ambulance.
(a) Name the type of mirror which is used as a rear view mirror and why?
(b) Mention values did Namit exhibit. (Value Based Question]
Answer:
(a) Convex mirror is a mirror which is used as a rearview mirror. It is used to get a wide view of traffic behind.
(b) The values exhibit by Namit here is courtesy concerned for other, sympathy, knowledgeable.

Question 6.
One day, Ramesh’s friend was performing their respective experiments given by their teacher. While sitting in the practical lab instead of performing experiment, Ramesh was playing with his meter scale. All the sudden, he held the scale in his hand and started moving in front of tubelight, then he observed the seven colours of white light. After sometimes, he got scolded by his lab teacher for not performing the experiment.
(a) Give the name of phenomenon that leads to the formation of band of seven colours.
(b) Name the constituent colours of white light.
(c) Mention the values shown by Ramesh here. (Value Based Question]
Answer:
(a) Dispersion of white light is the name of phenomenon which leads to the formation of band of seven colours.
(b) There are seven constituent colours of white light, they are Violet, Indigo, Blue, Green, Yellow, Orange, Red (i.e. VIBGYOR).
(c) Ramesh seems to be quite innovative with respect to the scientific methods and also very eager to learn science regarding phenomena.

Question 7.
Last Sunday Girish’s mother, Priyanka was preparing the dinner in her kitchen for Girish and his father. Both of them were feeling so much hungry and they sat ideally on their respective chairs and having empty plates and spoons on their dinning table. They were shouting like a 5 years old child that they wanted the dinner so much eagerly in order to fulfil their stomach. At the sometime, Girish’s mother served the cooked food to both of them and the moment, when Girish was just about to eat the rice with the help of spoon, he noticed that the spoon has such a shining surface that it reflected the light rays incident on it.
(a) Explain the importance of shining surface in the reflection of light.
(b) Name the type of spherical mirror represented by the shining steel spoon.
(c) Mention the values shown by Priyanka here towards her family. [Value Based Question]
Answer:
(a) As we know that the extent of reflection depends upon the shining of surface. So, greater the shining of the surface, more will be the reflection.
(b) Both convex and concave mirrors are represented by the shining steel spoon.
(c) The values shown by Priyanka here is concern and a satisfaction that she gets after serving the cooked food to her son and her husband.

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CHAPTER – 14 Electric Current and Its Effects | CLASS 7TH | NCERT SCIENCE IMPORTANT QUESTIONS & MCQS | EDUGROWN

SCIENCE IMPORTANT QUESTIONS & MCQS FOR CLASS 7th

Get Chapter Wise MCQ Questions for Class 7 Science with Answers prepared here according to the latest CBSE syllabus and NCERT curriculum. Students can practice CBSE Class 7 Science MCQs Multiple Choice Questions with Answers to score good marks in the examination.  Students can also visit the most accurate and elaborate NCERT Solutions for Class 7Science. Every question of the textbook has been answered here.

Chapter - 14 Electric Current and Its Effects

Question 1.
In making a battery
(a) positive terminal of one cell is connected to the negative terminal of the next cell
(b) positive terminal of one cell is connected to the positive terminal of the next cell
(c) negative terminal of one cell is connected to the negative terminal of the next cell
(d) none of the above

Answer

Answer: (a) positive terminal of one cell is connected to the negative terminal of the next cell


Question 2.
Where can the key or switch be placed in the circuit?
(a) Left side of the battery
(b) Right side of the battery
(c) Can be placed anywhere in the circuit
(d) Near the positive terminal of the bulb

Answer

Answer: (c) Can be placed anywhere in the circuit


Question 3.
Which one of the following is based on the heating effect of current?
(a) Geyser
(b) Hair dryer
(c) Immersion rod
(d) All of these

Answer

Answer: (d) All of these


Question 4.
The coil of wire contained in an electric heater is known as
(a) component
(b) element
(c) circuit
(d) spring

Answer

Answer: (b) element


Question 5.
The amount of heat produced in a wire depends on
(a) material
(b) length
(c) thickness
(d) all of these

Answer

Answer: (d) all of these


Question 6.
Which mark is necessary on electric appliances?
(a) AGMARK
(b) ISI
(c) FICCI
(d) KSK

Answer

Answer: (b) ISI


Question 7.
When an electric current flows through a copper wire AB as shown in Figure, the wire
MCQ Questions for Class 7 Science Chapter 14 Electric Current and Its Effects with Answers 1
(a) deflects a magnetic needle placed near it
(b) becomes red hot
(c) gives electric shock
(d) behaves like a fuse

Answer

Answer: (a) deflects a magnetic needle placed near it


Question 8.
Choose the statement which is not correct in the case of an electric fuse.
(a) Fuses are inserted in electric circuits of all buildings.


(b) There is a maximum limit on the current which can safely flow through the electric circuits.


(c) There is a minimum limit on the current which can safely flow in the electric circuits.
(d) If a proper fuse is inserted in a circuit it will blow off if current exceeds the safe limit.

Answer

Answer: (c) There is a minimum limit on the current which can safely flow in the electric circuits.


Question 9.
When a switch is in OFF position.
(i) circuit starting from the positive terminal of the cell stops at the switch.
(ii) circuit is open.
(iii) no current flows through it.
(iv) current flows after some time.
Choose the combination of correct answer from the following:
(a) all are correct
(b) (ii) and (iii) are correct
(c) only (iv) is correct
(d) only (i) and (ii) are correct

Answer

Answer: (b) (ii) and (iii) are correct


Question 10.
Which of the following precautions need not be taken while using electric gadgets / appliances/circuit?
(a) We should never touch a lighted electric bulb connected to the mains.


(b) We should never experiment with the electric supply from the mains or a generator or an inverter.
(c) We should never use just any wire or strip of metal in place of a fuse.
(d) We should never turn the switch in ON position.

Answer

Answer: (d) We should never turn the switch in ON position.


Match the following:

Column AColumn B
(i) Switch(a) Coil of wire which heats up when electricity current is supplied
(ii) Battery(b) Blows off, if the current exceeds safe limit
(iii) Element(c) Consumes less energy than a bulb
(iv) Filament(d) Mark that ensures that the electric appliance is safe to handle
(v) Fuse(e) Supplies current to the circuit
(vi) MCBs(f) Turns the circuit ON and OFF
(vii) CFL(g) Turn OFF if current exceeds safe limit
(viii) ISI(h) Wire in the bulb which glows
Answer

Answer:

Column AColumn B
(i) Switch(f) Turns the circuit ON and OFF
(ii) Battery(e) Supplies current to the circuit
(iii) Element(a) Coil of wire which heats up when electricity current is supplied
(iv) Filament(h) Wire in the bulb which glows
(v) Fuse(b) Blows off, if the current exceeds safe limit
(vi) MCBs(g) Turn OFF if current exceeds safe limit
(vii) CFL(c) Consumes less energy than a bulb
(viii) ISI(d) Mark that ensures that the electric appliance is safe to handle

Fill in the blanks:

1. Our body is a ………………….. of electricity.

Answer

Answer: conductor


2. An electric cell produces electricity from the ………………….. in it.

Answer

Answer: chemicals stored


3. In an electric circuit a fuse is a ………………….. to prevent possible fire.

Answer

Answer: safety device


4. A combination of two or more cells is called a ………………….. .

Answer

Answer: battery


5. The coil of wire in an electric heater is called an ………………….. .

Answer

Answer: element


6. A ………………….. is a safety device which prevents damages to electrical circuits and possible fires.

Answer

Answer: fuse


7. The wire gets ………………….. when an electric current passes through it.

Answer

Answer: hot


8. We must look for ………………….. mark on electrical appliances.

Answer

Answer: ISI


9. When electric current passes through a wire, it behaves like a magnet. It is the ………………….. effect of current.

Answer

Answer: magnetic


10. Crane has a strong ………………….. attached to it.

Answer

Answer: electromagnet


Choose the true and false statements from the following:

1. It is convenient to represent electric components by symbols.

Answer

Answer: True


2. A connecting wire is symbolized by a zig-zag line in the circuit diagram.

Answer

Answer: False


3. When an electric current flows through a wire, the wire gets heated.

Answer

Answer: True


4. The key or switch can be placed anywhere in the circuit.

Answer

Answer: True


5. The amount of heat produced in a wire depends on its material, length and thickness.

Answer

Answer: True


6. CFLs consume more electricity than ordinary bulbs.

Answer

Answer: False


7. For different requirements, the wires of different materials, different lengths and thicknesses are used.

Answer

Answer: True


8. A fuse is used to save energy in electrical circuits.

Answer

Answer: False


9. MCBs are the switches which automatically turn off when current in a circuit exceeds the safe limit.

Answer

Answer: True


10. When an electric current flows through a wire, it behaves like a magnet.

Answer

Answer: True

Question 1.
Mention the name of the two devices that work on the basis of magnetic effects of current.
Answer:
The devices that work on the basis of magnetic effects of current are loudspeaker and electric bell.

Question 2.
Name the device used these days in place of eiectric fuses in electrical circuits.
Answer:
The device used in these days in place of electric fuse is MCB (Miniature Circuit Breaker).

Question 3.
State the property of a conducting wire is utilised in making electric fuse. INCERT Exemplar]
Answer:
Electric fuse wire is made up of special material which has low melting point. As if high amount of current is passed, it melts to disconnect the electric circuit and prevent us from causing any damage.

Question 4.
Explain why are CFLs (Compact Fluorescent Lamps) preferred over electric bulbs. [NCERT Exemplar; HOTS]
Answer:
Compact fluorescent lamps are preferred over electric bulbs because electric bulbs use more power of electricity and it also losses electrical energy in the form of heat but it is not so in compact fluorescent lamps.

Question 5.
Name the type of mark for which we should look at an electrical appliance before buying, [HOTS]
Answer:
ISI mark is a mark for which we should look at an electrical appliance before buying.

Question 6.
Briefly mention which part of the symbol of battery shows positive and negative terminals?
Answer:
Electric Current and Its Effects Class 7 Extra Questions Science Chapter 14 1
The positive terminal is represented by longer vertical line while negative terminal is represented by shorter vertical line.

Question 7.
Briefly state the effects of electricity.
Answer:
The three effects of electricity are

  • Chemical effect
  • Heating effect
  • Magnetic effect

Question 8.
When does a circuit is said to be overloaded?
Answer:
It is overloaded by connecting too many devices to it. When too many devices get connected, then a circuit is said to be overloaded.

Question 9.
Why is an electric fuse required in all electrical appliance? [NCERT Exemplar]
Answer:
Electric fuse is required in all electrical appliances to prevent damage from excessive current flow and during short circuit.

Question 10.
Give the name any two electrical appliances in which electromagnets are used.
Answer:
Electric fan and electrical motor are the electrical appliances in which electromagnets are used.

Question 11.
Paheli does not have a night lamp in her room. She covered the bulb of her room with a towel in the night to get dim light. Has she taken the right step? Give one reason to justify your answer. [NCERT Exemplar; HOTS]
Answer:
No, she has not taken the right step. Because due to excessive heat of bulb, the towel may burn and it also results in the wastage of electrical energy.

Question 12.
The nails attract the pins. Comment.
Answer:
When the current is passed through the wire wound on the nail, it behave as electromagnet. Due to this reason, the nails attract the pins.

Question 13.
Name the scientist who discovered the magnetic effect of electric current.
Answer:
The scientist who discovered the magnetic effect of electric current is Hans Christian Oersted.

Question 14.
If the filament of the bulb is broken, would the circuit be complete? Would the bulb still glow?
Answer:
If the filament of the bulb is broken, the circuit will not be complete.
So, the bulb will not glow.

Question 15.
Name some electric appliances where the heating effect of the electric current is used.
Answer:
Some of the electric appliances where the heating effect of the electric current is used are electric heater, geyser, micro-oven, room heater, boiler, etc.

Question 16.
If the current through the coil stops flowing. Will the coil remain an electromagnet?
Answer:
When the current through the coil stops flowing, the coil does not remain an electromagnet.

Question 17.
State whether the bulb glows when the circuit is opened.
Answer:
No, the bulb does not glow when the circuit is opened. The bulb glows only when the circuit is closed.

Question 18.
What happens to the current in a circuit at the time of short circuit?
Answer:
The value of the current in a circuit increases heavily at the time of short circuit.

Question 19.
We should not touch the lighted bulb. Explain, why.
Answer:
The lighted bulb connected to main supply should not be touched by our hand directly, as a lighted bulb can be very hot and can burn our hand as well.

Electric Current and Its Effects Class 7 Science Extra Questions Short Answer Type Questions

Question 1.
Name two electric devices for each where
(a) heating effect of current is used and
(b) magnetic effect of current is used. [NCERT Exemplar]
Answer:
(a) Heating effect of current is used in electric heater and geyser.
(b) Magnetic effect of current is used in electric bell and cranes to lift heavy magnetic materials from one place to other.

Question 2.
Why do we cover plug pinholes which are within the reach of children with cellotape or a plastic cover when not in use? [NCERT Exemplar; HOTS]
Answer:
We do cover plug pinholes which are within the reach of children with cellotape or plastic cover to avoid electric shocks. If unconsciously, a child puts his finger in the electric socket, the shock may be fatal.

Question 3.
Can we use the same fuse in a geyser and a television set? Explain. [NCERT Exemplar; HOTS]
Answer:
No, we cannot use same fuse in a geyser and in a television set because the fuse used in every appliances has some limit to withstand the current flows through it. So, different appliances have different fuses.

Question 4.
If cells are placed side by side. Then, how are the terminals of the cells connected?
Answer:
If cells are placed side by side, then with the help of some connecting wires, the positive terminal of one cell is connected to the negative terminal of other to produce a combined power of all cells which can be called a battery.

Question 5.
Explain how a battery can be constructed.
Answer:
As we know that a battery is a combination of two or more cells and it can be constructed by placing cells property on cell holder in such a way that the positive terminal of one cell is connected to the negative terminal of other.
A piece of wire is connected to each of the two metal clips on the cells holder.

Question 6.
Distinguish between an open circuit and a closed circuit.
Answer:
Difference between an open circuit and a closed circuit

Open (Electric) circuitClosed (Electric) circuit
An open electric circuit is or electric path which begins from the positive terminal of a battery or cell, gets broken at some point.A closed circuit is an electric path which begins from the positive terminal of a cell or battery and terminates at its negative terminal without any break.

Question 7.
Boojho made an electromagnet by winding 50 turns of wire over an iron screw. Paheli also made an electromagnet by winding 100 turns over a similar iron screw. Which electromagnet will attract more pins? Give reason. [NCERT Exemplar; HOTS]
Answer:
Since the magnetic effect directly depends on the number of turns of the coil. As, Paheli’s coil has more number of turns than Boojho. So, her electromagnet is stronger than Boojho.
So, electromagnet of Paheli attracts more pins as compared to Boojho.

Question 8.
Does the electric current have other effect except heating? Name it.
Answer:
Yes, electric current have other effect except heating, i.e. magnetic effect of current.
When electric current is passed through a coil, there is a magnetic field developed around the coil or wire, if magnetic compass is placed near by, it deflects the magnetic needle.

Question 9.
Explain the following.
(a) Copper and aluminium wires are usually employed for electricity transmission. Explain the reason.
(b) Explain how does the resistance of a wire vary with its length.
(c) The tungsten is used almost exclusively for filament of electric lamp. Comment.
Answer:
(a) Due to the low resistance and strength of aluminium and coppers, both these metals are usually employed for the transmission of electricity.
(b) There is always an increase in the length of the wire with the increase in its resistance.
(c) Since tungsten has high melting point and high resistance. So, that is why, the tungsten is used exclusively for filament of electric lamp.

Question 10.
If we connect more cells in the circuit, then what will happen?
Answer:
If we connect more of cells in the circuit, then the nail will attract more pins. It is due to the reason that the current flowing through the wire wound on the nail will get increase which in turn will increase the strength of the electromagnet.

Question 11.
Electromagnets are better than permanent magnets. Explain why.
Answer:
An electromagnet can be switched OFF or switched ON as desired and this is not possible in the permanent magnets. That is why the electromagnets are better than the permanent magnets.

Question 12.
If the current flows through wire, does the wire behave like a magnet?
Answer:
When the current flows through any wire, a magnetic field is developed around that wire or coil and it behaves like magnet. It can be analysed by placing a magnetic compass around the wire, it will show deflection of the needle.

Question 13.
If current is passed through a coil, does the pins cling to the coil?
Answer:
When an electric current is passed through a coil, it gets magnetised due to phenomena of magnetic effect of current. When magnetic materials such as pins are placed near to it. It gets attracted by the coil or we can say that pins cling to the coil.

Question 14.
Batteries used in tractors, trucks and inverters are also made from cells. Then why it is called a battery? [HOTS]
Answer:
The cell is the unit of battery when more than one cell are combined together, it forms a battery. In trucks, tractors and inverters, cells are internally arranged and we need not to connect it externally, so we called it as batteries.

Electric Current and Its Effects Class 7 Science Extra Questions Long Answer Type Questions

Question 1.
One day, Pinki was ironing the clothes in her room. After half an iron of ironing, the light went off and Pinki went outside to the lobby of her house to check it there was any problem in the household circuit. At the same time, she listened the voice of her 4 years old daughter from the same room where she was ironing the clothes. Her daughter was about to touch the hot electric iron but at the same moment, Pinki entered in the room and pushed her daughter back from that place.
(a) On which effect of electric current, does the electric iron works?
(b) Mention the values showed by Pinki here. [Value Based Question]
Answer:
(a) The electric iron works on the basis of heating effect of electric current.
(b) The values showed by Pinki here is a great concern and love towards her own 4 years old daughter.

Question 2.
Explain with the help of a diagram, how does the magnetic effect of electric current help in the working of an electric bell.
Answer:
In order to ring the bell first of all we press the push button switch in order to ring the bell. So, when we press the switch, then the electric circuit of the bell is completed and a current passes through the coil of the electromagnet and it gets magnetised. The electromagnet attracts the iron armature towards itself.

So, as the armature moves towards the poles of the electromagnet, the clapper attached to it strikes the gong and produces a ringing sound. It implies that the bell rings.

When the armature moves towards the magnet, its contact with the contact screw is broken. Due to this, the electric circuit breaks and no current flows in the electromagnet coil. The electromagnet loses its magnetism for a moment and the armature is no longer attracted by it. The flat spring brings back the iron armature to its original position and the clapper also moves away from the gong.
Electric Current and Its Effects Class 7 Extra Questions Science Chapter 14 2
As soon as the armature comes back and touches the contact screw the circuit is completed and current starts flowing in the electromagnet coil again. The electromagnet attracts the iron armature once again and the clapper strikes the gong again producing a ringing sound.

So, this process of ‘make and break’ of the electric circuit continues as long as we are pressing the switch. Due to this, the armature vibrates forwards and backwards rapidly each time making the clapper strike the gong. Thus, the clapper strikes the gong rapidly producing almost continuous sound.

Question 3.
State one measure to avoid overloading in an electrical circuit. Also mention the name given to a situation in which the live and the neutral wires accidently come in contact. Describe the role of a safety device in this situation.
Answer:
Overloading can be avoided if too many appliances are not connected to a single socket. Short circuiting is a name given to a situation in which the live and the neutral wires accidently come in contact.

Electric fuse is a safety device. When a short circuit takes place or when overloading takes place, then the current becomes large and heats the fuse wire too much and thus, it gets melted and circuit breaks which prevents the damage of the wiring and electrical appliances.

Question 4.
Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness both of them connected with wires as shown in the circuit given in figure. The current flowing in both the circuits is the same.
(a) Will the heat produced in both the cases be equal? Explain.
(b) Will the heat produced be the same, if the wires taken by them are of equal lengths but of different thickness? Explain.
Electric Current and Its Effects Class 7 Extra Questions Science Chapter 14 3
Answer:
(a) No, the amount of heat produced in both the wires will be different because amount of heat produced in a wire on passing electric current depends on the length of wire and here length is different for both the wires.
(b) No, the amount of heat produced in the wire of same length but different thickness cannot be same because amount of heat produced in a wire also depends on the thickness of the wire.

Question 5.
Last Sunday, Pulpit was playing videotape in his room. While playing, the electricity of his house went off due to which he could not able to see anything around him. Then anyhow, he managed to get his mobile in his hand and with the help of its light, he went outside of his room to check if there was any problem in the electric circuit board of his house.
At the same time, his father suggested him to maintain the distance from the circuit board and decided to call some electrician to check the problem.
(a) Explain, what happens when live wire and neutral wire touches each other directly?
(b) State the values here showed by Pulkit’s father. [Value Bated Question]
Answer:
(a) When live and neutral wire touches each other directly then it leads to short circuit in which the large amount of current flows through the household wiring and this large current may heat the wires to a dangerously high temperature and a fire may be started.
(b) Pulkit’s father seems very sensible in taking the decisions and he showed a very great concern towards his son

 

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CHAPTER – 13 Motion and Time | CLASS 7TH | NCERT SCIENCE IMPORTANT QUESTIONS & MCQS | EDUGROWN

SCIENCE IMPORTANT QUESTIONS & MCQS FOR CLASS 7th

Get Chapter Wise MCQ Questions for Class 7 Science with Answers prepared here according to the latest CBSE syllabus and NCERT curriculum. Students can practice CBSE Class 7 Science MCQs Multiple Choice Questions with Answers to score good marks in the examination.  Students can also visit the most accurate and elaborate NCERT Solutions for Class 7Science. Every question of the textbook has been answered here.

Chapter - 13 Motion and Time

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CHAPTER – 12 Reproduction in Plants | CLASS 7TH | NCERT SCIENCE IMPORTANT QUESTIONS & MCQS | EDUGROWN

SCIENCE IMPORTANT QUESTIONS & MCQS FOR CLASS 7th

Get Chapter Wise MCQ Questions for Class 7 Science with Answers prepared here according to the latest CBSE syllabus and NCERT curriculum. Students can practice CBSE Class 7 Science MCQs Multiple Choice Questions with Answers to score good marks in the examination.  Students can also visit the most accurate and elaborate NCERT Solutions for Class 7Science. Every question of the textbook has been answered here.

Chapter - 12 Reproduction in Plants

MCQs

Question 1.
Vegetative propagation in potato takes place by
(a) leaves
(b) stem
(c) root
(d) seed

Answer

Answer: (b) stem


Question 2.
In which of the following plants buds are present on the margins of leaves?
(a) Bryophyllum
(b) Touch me not
(c) Chandan
(d) Coriander

Answer

Answer: (a) Bryophyllum


Question 3.
In yeasts reproduction occurs by
(a) fragmentation
(b) binary fission
(c) budding
(d) spore formation

Answer

Answer: (c) budding


Question 4.
Which of the following parts of a plant take part in sexual reproduction?
(i) Flower
(ii) Seed
(iii) Fruit
(iv) Branch
Choose the correct answer from below:
(a) (i) and (ii)
(b) (i), (ii) and (iii)
(c) (iii) and (iv)
(d) (ii), (iii) and (iv)

Answer

Answer: (b) (i), (ii) and (iii)


Question 5.
Lila observed that a pond with clear water was covered up with a green algae within a week. By which method of reproduction did the algae spread so rapidly ?
(a) Budding
(b) Sexual reproduction
(c) Fragmentation
(d) Pollination

Answer

Answer: (c) Fragmentation


Question 6.
Seeds of drumstick and maple are carried to long distances by wind because they possess
(a) winged seeds
(b) large and hairy seeds
(c) long and ridged fruits
(d) spiny seeds

Answer

Answer: (a) winged seeds


Question 7.
The ‘eye of the potato plant is what
(a) the root is to any plant
(b) the bud is to a flower
(c) the bud is to Bryophyllum leaf
(d) the anther is to stamen

Answer

Answer: (c) the bud is to Bryophyllum leaf


Question 8.
The ovaries of different flowers may contain
(a) only one ovule
(b) many ovules
(c) one to many ovules
(d) only two ovules

Answer

Answer: (c) one to many ovules


Question 9.
Which of the following statements is/are true for sexual reproduction in plants?
(i) Plants are obtained from seeds
(ii) Two plants are always essential
(iii) Fertilisation can occur only after pollination
(iv) Only insects are agents of pollination
Choose from the options given below:
(a) (i) and (ii)
(b) (i) only
(c) (i) and (ii)
(d) (i) and (iv)

Answer

Answer: (a) (i) and (ii)


Question 10.
Pollination refers to the:
(a) transfer of pollen from anther to ovary
(b) transfer of male gametes from anther to stigma
(c) transfer of pollen from anther to stigma
(d) transfer of pollen from anther to ovule

Answer

Answer: (c) transfer of pollen from anther to stigma


Match the following:

Column AColumn B
(i) Bread mould(a) Cutting
(ii) Yeast(b) Leaves
(iii) Potato(c) Fragmentation
(iv) Bose(d) Detached body part
(v) Sweet potato(e) Spores
(vi) Bryophyllum(f) Eye
(vii) Cactus(g) Roots
(viii) Spirogyra(h) Budding
Answer

Answer:

Column AColumn B
(i) Bread mould(e) Spores
(ii) Yeast(h) Budding
(iii) Potato(f) Eye
(iv) Bose(a) Cutting
(v) Sweet potato(g) Roots
(vi) Bryophyllum(b) Leaves
(vii) Cactus(d) Detached body part
(viii) Spirogyra(c) Fragmentation

Fill in the blanks:

1. In …………………. reproduction, one individual can produce many individuals from its body parts.

Answer

Answer: asexual


2. Both stamen and carpel are present in …………………. flowers.

Answer

Answer: bisexual


3. Budding is a type of …………………. reproduction.

Answer

Answer: asexual


4. The process of …………………. ensures continuity of life on the earth.

Answer

Answer: reproduction


5. …………………. are the reproductive parts of a plant.

Answer

Answer: Flowers


6. Buds in potato are also called ………………….

Answer

Answer: eyes


7. Plants produce seeds as a result of …………………. reproduction.

Answer

Answer: sexual


8. The small bulb like projection coming out from the yeast cell is called a ………………….

Answer

Answer: bud


9. The …………………. develops into an embryo.

Answer

Answer: zygote


10. The fruits are ripened ………………….

Answer

Answer: ovary


Choose the true and false statements from the following:

1. Two individuals are needed for a sexual reproduction.

Answer

Answer: True


2. Seed is the only structure which develops into new plant.

Answer

Answer: False


3. Plants such as cacti produce new plants when their parts get detached from the main plant body.

Answer

Answer: True


4. Plants produced by vegetative propagation take less time to grow and bear flower and fruit.

Answer

Answer: True


5. The spores are asexual reproductive bodies.

Answer

Answer: True


6. Anther contains female gametes called eggs.

Answer

Answer: False


7. The fruit is ripened ovary.

Answer

Answer: True


8. Seed dispersal in coconut is aided by winds.

Answer

Answer: False


9. Fusion of male and female gametes is called pollination.

Answer

Answer: False


10. A bisexual flower has both male and female reproductive parts.

Answer

Answer: True

Question 1.
Why is the process of reproduction necessary?
Answer:
The process of reproduction is necessary for the perpetuation and preservation of species and to increase the number of members of species.

Question 2.
If the filament of Spirogyra is broken into fragments. What will you observe?
Answer:
If the filament of Spirogyra are broken into fragments, then each fragment will develop into a new plant.

Question 3.
Fungus, moss and fern reproduce by a common method of asexual reproduction. Name the method. [NCERT Exemplar]
Answer:
Fungus, moss and fern reproduce by the common method of spore formation which is a type of asexual reproduction.

Question 4.
A flower consists of different parts. Name these parts of a flower.
Answer:
The four main parts of a flower are
(i) Sepals
(ii) Petals
(iii) Stamen
(iv) Pistil

Question 5.
Mention the mode of reproduction in the following plants
(a) Spirogyra
(b) Yeast
(c) Money plants
Answer:
(a) Spirogyra – fragmentation
(b) Yeast – budding
(c) Money plant – Vegetative propagation

Question 6.
Pick the odd one out from the following on the basis of mode of reproduction and give reason for it, Sugarcane, Potato, Rice, Rose. [NCERT Exemplar]
Answer:
The odd one out is rice.
In the above given pairs as rice reproduces by sexual reproduction and sugarcane, potato and rose reproduces vegetatively.

Question 7.
Give one difference between unisexual and bisexual flower.
Answer:
Unisexual flowers are those which contain either male or female reproductive part and bisexual flower has both reproductive parts (i.e. male and female) on the same flower.

Question 8.
Flowers are colourful and fragrant. Give reason supporting the statement. [HOTS]
Answer:
Flowers are so colourful because they absorb and reflect light energy. Fragrance results from production of volatile chemicals which evaporate.

Question 9.
Boojho had the following parts of a rose plant-a leaf, roots, a branch, a flower, a bud and pollen grains. Which of them can be used to grow a new rose plant? [NCERT Exemplar]
Answer:
Branch can be used to grow a new rose plant. As, rose reproduces by vegetative propagation, i.e. stem cutting method.

Question 10.
Formation of new but similar individuals from parents is characteristic feature of which process?
Answer:
Reproduction is the process of production of new similar organisms from their parents.

Question 11.
Name two plants where vegetative reproduction takes place by roots.
Answer:
Sweet potato and dahlia develops new plants through their roots by the process of vegetative reproduction.

Question 12.
A yellow powdery substance is present in the anther which participates in reproduction process. Name this substance.
Answer:
Pollen grains.

Question 13.
In which part of flower does fertilisation occur?
Answer:
Ovary is the part where male and female gametes fuse together.

Question 14.
Bryophyllum leaves reproduce using which mode of reproduction?
Answer:
Asexually by vegetative propagation.

Question 15.
Which type of pollination does the given figure indicate?
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 1
Answer:
The given figure shows self-pollination, as the pollen grains from anther of flower are transferred to the stigma of same flower.

Question 16.
What are the bulb-like projections forming in yeasts?
Answer:
The bulb-like projections formed during reproduction are called buds.

Question 17.
‘Spores’ as a means of asexual reproduction are used by which plants?
Answer:
Spores are produced by fungi, ferns and mosses during unfavourable conditions.

Question 18.
Write the male and female reproductive parts present on the flowers.
Answer:
The male reproductive part is stamen and the female reproductive part is pistil.

Question 19.
Pollen grains are present inside anthers for long time yet they do not die. Why?
Answer:
Pollen grains have a tough protective coat which presents them from drying up.

Question 20.
Name two plants in which pollination occurs by water.
Answer:
Vallisneria and Hydrilla.

Question 21.
Fruit is the ripened ovary of a flower. Explain.
Answer:
After fertilisation, the ovary of a flower develops and becomes a fruit with seeds present inside.

Question 22.
Banana is a fruit without seeds. Give reason.
Answer:
Banana forms from one parent only. There is no seed production.

Reproduction in Plants Class 7 Science Extra Questions Short Answer Type Questions

Question 1.
When you keep food items like bread and fruits outside for a long time especially during the rainy season, you will observe a cottony growth on them. [NCERT Exemplar; HOTS]
(a) What is this growth called?
(b) How does the growth take place?
Answer:
(a) When food items like bread and fruits are kept outside for a long time especially during rainy season, a cottony growth of bread mould, a fungus is observed.
(b) This growth of fungus takes place by spores present in air, which when comes in the contact with moisture in bread germinates and grow to produce new cells.

Question 2.
Collect some flower of different plants like papaya, rose, mustard, lady’s finger, Petunia, cucumber, corn, pea, etc. Group them under following heads.
(a) Which of these plants have unisexual flowers?
(b) Which of these plants have bisexual flower?
(c) What is the other name of unisexual and bisexual flower? [HOTS]
Answer:
(a) Unisexual flowers are papaya, cucumber, com.
(b) Bisexual flowers are rose, mustard, lady’s finger, Petunia, pea.
(c) Unisexual flowers are also called as incomplete flower while bisexual flowers are called hermaphrodite or complete flowers.

Question 3.
In the figure given below, label the part marked (i), (ii) and (iii). [NCERT Exemplar]
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 2
Answer:
The parts in the given figure are labelled as follows
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 3

Question 4.
Coconut is a large and heavy fruit. How is it adapted for dispersal by water? [NCERT Exemplar]
Answer:
The seeds of some plants that have an outer fibrous or spongy covering are dispersed through water. They have the ability to float in the water and drift along with its flow, e.g. seeds of water lily, lotus, chestnut (singhara) and coconut are dispersed through water. The coconut fruits have a fibrous outer coat which enables them to float in water and carried away by flowing water to far off places.

Question 5.
What is a bud? Which organism reproduce by budding? Given the diagrammatic representation of budding in a plant.
Answer:
Buds are small bulb-like projections of yeast cell.
These are asexual reproducing bodies of yeast.
Diagrammatic representation of budding in yeast Refer to figure on page 178.

Question 6.
Group the seeds given in figure (i) to (iii) according to their means of dispersion.
(a) Seed dispersed by wind.
(b) Seed dispersed by water.
(c) Seed dispersed by animal. [NCERT Exemplar]
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 4
Answer:
The seeds and their means of dispersal can be given as follows:
(a) The seed of maple is dispersed by wind. It has winged seed which are light in weight.
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 5
(b) Seed of aak or madar has hairy outgrowth which makes it lighter and can be dispersed by wind.
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 6
(c) Seed of Xanthium have numerous spines on them which gets attached to the fur of animals. Hence, these are dispersed by animals.
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 7
None of the seed given in the figure is dispersed by water

Question 7.
How does male gamete present in pollen grain reaches female gamete present in ovule?
Answer:
After pollination, the pollen grains fall on the surface of stigma and germinate to form a long tube, reaching the ovules inside the ovary, the egg or female gamete is present in the ovule.
The outer surface of pollen grains rupture and male gametes are released to fuse with egg.

Question 8.
How do the plants like sugarcane, potato and rose reproduce when they cannot produce seeds?
Answer:
Sugarcane and rose are propagated by stem cutting that is a method of vegetative propagation, in which stem is capable of growing into a mature independent plants that are identical to their parents.

Potato is an underground modified stem having bud called eyes, which sprout and develop into a new identical plant.
Thus, the plants which cannot produce seeds, can be propagated vegetatively with the help of vegetative parts such as stem, roots, buds and leaves.

Question 9.
Mention the benefits of seed dispersal.
Answer:
Benefits of Seed Dispersals

  • Seed dispersal avoids overcrowding of young plants around their parent plants.
  • It helps in preventing competition between the plants and its own seedlings for sunlight, water and minerals.
  • One of the benefits of seed dispersal is that it enables the plant to grow into new habitats for wider distribution and provides them with better chance of survival.

Question 10.
What is meant by the term fertilisation? List the stepwise manner leading to formation of an embryo.
Answer:
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 8
The process in which the male gamete fuses with female gamete to form a new cell (called zygote) is called fertilisation.
When the pollens are deposited on the stigma of the pistil, it begins to germinate. After sometime, a long pollen tube is developed from the pollen grain which passes through the style towards the female gametes in the ovary. The male gametes move down the pollen tube and the tube enters the ovule present inside the ovary.

The tip of pollen tube bursts and the male gamete comes out of the pollen tube. Inside the ovary, the male gametes fuse with the female gametes present in the ovule to form a fertilised egg cell which is called zygote.
The zygote develops into an embryo which is a part of a seed that develops into a new plant.

Question 11.
A student was given a flower. He was asked to pick the different whorls of flower by the forcep. He pulled each part of the flower and laid them on the chart paper in a sequence and named them W, X, Y, Z (from outer to inner whorl). He was unable to name them.
Help the student to name the different parts of a flower. Also help him to tell which part produces male gamete and female gametes. [HOTS]
Answer:
The four whorls of the flower are outermost whorl ‘W’ is green part which is called sepal. Inside sepal the next whorl is X which is coloured and attractive part of the flower called petals. The Y is the inner whorl of flower called stamen. It is the male reproductive part of flower. It consist of two parts, i.e. anther and filament. The anther contains male gametes called pollen grain. The whorl ‘Z’ is the innermost part of the flower called pistil. It is the female reproductive part of flower. It consist of three parts, i.e. stigma, style and ovary. The ovary produces ovule which contains the female gametes or egg cell.

Question 12.
One morning as Paheli strolled in her garden she noticed many small plants, which were not there a week ago. She wondered, where they had come from as nobody had planted them there. Explain the reason for the growth of these plants. [NCERT Exemplar; HOTS]
Answer:
The small plants which were not there in the garden a weak ago have grown up due to seed dispersal. The seeds from the tree may have fallen below or have been dispersed by wind or animals on the ground, which on germination developed into new small plants.

Question 13.
Place a piece of bread in a moist and warm place for few days. Observe it after few days. What will you see?
(a) Name the organism that grows on the bread piece?
(b) What are the thread-like projections called?
(c) What is the knob like structure present on the top of thin stem called?
(d) Which type of reproduction does this organism shows?
(e) From where does the spors comes to the bread piece? [HOTS]
Answer:
(a) When the bread piece is kept in a moist and warm place for few days, bread mould grows on the bread piece.
(b) The thread-like projections are called hyphae or mycelium.
(c) The thin stem having knob-like structure on the top is called sporangia or sporangium which contains hundred of minute spores.
(d) Bread mould shows asexual mode of reproduction.
(e) These spores are present in the air and when favourable conditions arrive, the grow into new plants.

Question 14.
Write how the following seeds are dispersed.
(a) Seeds with wings
(b) Small and light seeds.
(c) Seeds with spines/hooks.
Answer:
The mode of dispersal of the seeds having following properties are as follows:
(a) Seeds with wings-like seeds of drumstick and maple become light weighted and can be blown away by air. Thus, these are dispersed by wind.
(b) Small and light seeds like seeds of grasses and cotton (having hairy growth) are also dispersed through wind.
(c) Seeds of Xanthium, Urena have spines and hooks on them, these hooks or spines are attached to the fur of the animal body. When animals move to other places and rub their body with tree, etc., these seeds fall from their body and get dispersed.. Therefore, these are dispersed through animals.

Question 15.
Why is vegetative propagation a preferred method of asexual reproduction?
Answer:
The following advantages of vegetative reproduction makes it a preferred method

  • It takes less time to grow and bear flower and fruits than those produced from seeds.
  • The new plants are the exact copies of parent plant because they are produced from a single parent.

Question 16.
Insects are called agents of pollination. How do they aid in process of pollination?
Answer:
Flowers have nectars that attract insects. Insects suck these nectars as their food. When insects like bee, butterfly, etc., sit on the flower for sucking nectar, the sticky pollen grains get attached to their legs and wings. When these insects again sit on another flower, these pollen grains are transferred to the stigma of that flower from the body of the insects. In this way, insects help in pollination.

Question 17.
What is seed dispersal? What will happen if all the seeds of a plant were to fall at a same place and grow?
Answer:
Plant produces large number of seeds. When these seeds fall down they starts growing. The process by which the seeds are scattered to different place (far and wide from their parents) is called seed dispersal.
The seeds and fruits are dispersed away through various agencies like air, water and animals. Sometimes dispersal takes place by the explosion or bursting of fruits. If all the seeds of a plant were to fall at the same place and grow, there will be a severe competition for sunlight, water, mineral and space. As a result, the survival for the plants will be difficult and the plants who survive will not grow into a healthy plants.

Question 18.
Describe the structure of a flower.
Answer:
The main parts of a flower are
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 9
(i) Sepals These are the green leaf-like outermost circle of the flower. All the sepals are together referred to as calyx. The function of calyx is to protect the flower when it is in bud form.

(ii) Petals These are the colourful and most attractive part of flower. These lie inside the sepals. All the petals are together referred to as corolla. These are scented and attract insects for pollination.

(iii) Stamen It is a male reproductive organ of plant. These are the little stalks with swollen top and lies inside the ring of petals. The stamen is made up of two parts, i.e. filament and anther. The stalk of stamen is called filament and the swollen top of stamen is called anther.
Anther contains the pollen grain which have male gamete in it. Pollen grains are exposed when the anther ripens and splits. These appear as the yellow powder like substance which is sticky in nature. Flowers usually have a number of stamens in it.

(iv) Pistil It is the female reproductive part of a flower that lies in the centre of a flower. These are flask-shaped structure which is made up of three parts, i.e. stigma, style and ovary.
The top part of pistil is called stigma. It receives the pollen grains from the anther during pollination. The middle part of the pistil is tube-like structure called style which connects stigma to the ovary.

The swollen bottom part at the base of pistil is called ovary.
The ovary makes ovules and stores them. These ovules contain the female sex cells also called as egg cell. It is the female gamete of flower. Pistil is also called as carpel. The pistil is surrounded by several stamens.
The base of the flower on which all the parts of flower are attached is called receptacle.

Question 19.
Observe the given figure?
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 10
(a) Which plant is this? Give the name of the plant.
(b) What does it shows?
(c) From where the new plants are developing?
Answer:
(a) The given figure is of Bryophyllum leaf. It is also called as sprout leaf plant.
(b) It shows vegetative reproduction by leaves.
(c) The leaves of Bryophyllum develops some buds in its margin or edges which grow into new plants, when buried in the soil.

Question 20.
The process of layering is commonly used in jasmine for reproduction. Explain how this process of layering is performed in jasmine. [HOTS]
Answer:
Layering is a method of vegetative reproduction in branches. In this method, a mature branch of parent plant is bent down and covered with soil.
The tip of the branch is kept above the ground. After few days the roots are developed from the branch buried under the soil and develops into a new plant. This method is done in the plants that have long and slender branches, e.g. jasmine.

Reproduction in Plants Class 7 Science Extra Questions Long Answer Type Questions

Question 1.
In the figure of a flower given below, label the parts whose functions are given below and give their names.
(a) The part which contains pollen grains.
(b) The part where the female gamete is formed.
(c) The female reproductive part, where pollen grains germinate.
(d) The colourful part of flower which attracts insects[NCERT Exemplar]
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 11
Answer:
The various parts of a flower whose functions are mentioned above are labelled as follows :
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 12

Question 2.
Observe the following figure and answer the following questions.
(a) Which type of vegetative propagation has been shown in this figure?
(b) Name two plants where this method of vegetative reproduction takes place.
(c) Is this a sexual or asexual mode of reproduction?
(d) Label the part (A) and (B) in the given figure.
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 13
Answer:
(a) The given figure shows grafting method (vegetative reproduction).
(b) Mango and rose are the two plants where this method of vegetative takes place.
(c) It is asexual method of reproduction.
(d) (A) Scion (B) Stock

Question 3.
Explain the process of reproduction in plants, involving the fusion of cells from male and female parts of a flower.
Answer:
When the reproduction in an organism includes two types of gametes, i.e male and female from two different parents, it is called sexual reproduction. The sexual reproduction takes place by the fusion of male and female gametes by the process called fertilisation to form zygote.
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 14
Sexual reproduction [fertilisation) in plants The different steps that take place during sexual reproduction in plants are

  • The pollens are deposited on stigma and begins to germinate.
  • Pollen tube containing male gametes reaches to the ovary of flower.
  • The tip of the pollen tubes gets dissolved and male gametes comes out of the pollen tube.
  • Inside the ovary male gametes fuse with the female gamete or egg present in the ovule.
  • The fusion of both the gametes will result into a fertilised egg cell which is also called as zygote.

Question 4.
Name some fruit bearing plants. Now make a table and describe the method of seed dispersal in these fruits as well as the part which helps in the seed dispersal.
Answer:
The method of seed dispersal in the fruits and the parts which help in the seed dispersal:
Name of fruits bearing plants Agents through which seeds are dispersd Parts or seeds which helps in dispersal

Name of fruits bearing plantsAgents through which seeds are dispersdParts or seeds which helps in dispersal
DrumstickAir/windWinged seeds
SunflowerWindHairy seeds
GokhruAnimalSpines and Hooks
CoconutWaterFibrous coating
LotusWaterThalamus float in water
PoppyExplosionPericarp bursts
GrassWindminute, light weighted seeds

Question 5.
Observe the given figure and answer the following questions.
(a) Name the plant?
(b) Which type of reproduction is seen in this plant?
(c) Is ginger a root or stem?
(d) Label the part of this plant?
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 15
Answer:
(a) The given figure is of ginger tuber.
(b) Asexual reproduction is seen in this plant.
(c) Ginger is a stem.
(d) Various parts of this plant can be shown as follows:
Reproduction in Plants Class 7 Extra Questions Science Chapter 12 16

Question 6.
Ria went to a plant nursery with her mother. The gardner approached them and asked about their choice of plant. Ria’s mother wanted a flowering plant with fragrance. Gardner showed them a plant and told them that this variety has been prepared by a method of vegetative propagation of stems.
Ria grew curious and asked some questions to gardner.
(a) What is vegetative propagation?
(b) What are methods of producing new plants using stem?
(c) Name any two plants where this method of reproduction is used. Is this a asexual or sexual method?
(d) What values do you observe in Ria? [Value Based Question]
Answer:
(a) Vegetative propagation is the process of reproduction in which new plants are produced from different parts of old plants like stem, roots or leaves.
(b) Cutting and grafting method are two methods where stem is used for vegetative propagation.
(c) Mango and rose are two plants cultivated using vegetative propagation.
This is an asexual method of reproduction.
(d) Ria is curious, inquiring who wants to gain knowledge about process occurring around here.

Question 7.
Ravi was sitting in a garden with his family. His younger sister comes running with different types of flowers and starts to name their parts. She stops as she forgets some names and Ravi noticing this comes to help her.
His sister askes many questions related to flowers and Ravi answers her with all information he has.
(a) What is a flower and mention its function during reproduction?
(b) Flowers help in pollination and fertilisation. Yes/No? Give reason.
(c) Do all flowers have both male and female parts on them specify?
(d) What values are observed in Ravi and his sister? (Value Based Question]
Answer:
(a) A flower is the reproductive part of plant which helps in sexual reproduction.
A flower ensures the occurrence of process of fertilisation.
(b) Yes, flower aids in both pollination and fertilisation. Different colours and fragrance of flowers attract insects to them causing dispersal of pollen grain ensuring pollination.
Fertilisation occurs in the ovary of the flower after pollination of male and female parts.
(c) Number of some flowers can either have male or female parts on them, these flowers are called unisexual.
Some flowers have both, the male and female parts on them so they are called bisexual flowers.
(d) Ravi is aware, sincere, helpful as he helps others and knowledgeable while his sister is inquisitive, ready to acquire new knowledge and observant.

 

 

 

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