CHAPTER – 1 Nutrition in Plants | CLASS 7TH |NCERT SCIENCE IMPORTANT QUESTIONS & MCQS | EDUGROWN

Answer: (d) All of these

Answer: (a) heterotrophs

Answer: (b) photosynthesis

Answer: (c) Leaves

Answer: (a) stomata

Answer: (c) Solar energy

Answer: (d) chlorophyll

Answer: (b) take carbon dioxide and release oxygen

Answer: (а) solar energy is converted into chemical energy

Answer: (а) CO₂

Answer: (a) carbohydrates, oxygen

Answer: (b) Cuscuta

Answer: (a) Fungi

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

Answer: (a) Pitcher plant

Answer:

Answer: food

Answer: photosynthesis, autotrophs

Answer: Solar

Answer: Fungi/s aprotrophs

Answer: host

Answer: heterotrophs

Answer: Oxygen, carbon dioxide

Answer: Chlorophyll

Answer: True

Answer: True

Answer: False

Answer: False

Important Questions

Question 1.
Potato and ginger are both underground parts that store food. Where is the food prepared in these plants? [NCERT Exemplar]
Anwer:
In both the plants, shoot system and leaves are above ground. They prepare food through photosynthesis and transport it to the underground part for storage.

Question 2.
Plants prepare their food using a different mode of nutrition than us. What is it?
Answer:
The mode of nutrition in plant is autotrophic, i.e. they synthesise their own food.

Question 3.
Photosynthesis requires chlorophyll and a few other raw materials. Add the missing raw materials to the list given below:
Water, minerals, (a) …… (b) …….
Answer:
(a) Sunlight
(b) Carbon dioxide

Question 4.
The tiny openings present on the leaf surface. What are they called?
Answer:
Stomata are the tiny pores present on the surface of leaves through which gaseous exchange takes place in plants.

Question 5.
What is the function of guard cells of stomata?
Answer:
Guard cells help in controlling the opening and closing of stomata for gaseous exchange.

Question 6.
Which parts of the plant are called food factories of the plant?
Answer:
Leaves are referred to as food factories of plants. This is because, leaves synthesise food by the process of photosynthesis.

Question 7.
A carbohydrate is produced by plants as food source. It is constituted from which molecules?
Answer:
Carbohydrates are composed of carbon, hydrogen and oxygen.

Question 8.
Why do some plants feed on insects?
Answer:
Insectivorous plants grow in soil which lack nitrogen, therefore they eat insects to fulfill their need of nitrogen.

Question 9.
Define parasites.
Answer:
Parasites they are those organisms which grow on other plants or animals for their food, e.g. Cuscuta.

Question 10.
Name the bacteria that can fix atmospheric nitrogen.
Answer:
Rhizobium is the bacterium which can fix atmospheric nitrogen.

Question 11.
Except plants, why can’t other living organisms prepare their food using CO₂, water and minerals? [HOTS]
Answer:
Our body does not contain chlorophyll for absorbing solar energy which is necessary for preparing food using air, water, etc.

Question 12.
A leguminous plant can restore the soil’s concentration of mineral nutrients. Can you give examples of some such plants?
Answer:
Plants such as gram, pulses and beans are leguminous.

Question 13.
Algae are green in colour. Why?
Answer:
Algae contain chlorophyll which imparts green colour to them.

Question 14.
what do you understand by nutrition?
Answer:
The process of utilising nutrients like carbohydrates, proteins, fats, etc., to generate energy is called nutrition.

Question 15.
Fungus can be harmful and useful. Give an example showing both of these traits of fungus.
Answer:
Fungus produces antibiotics like penicillin used to treat diseases and fungus can also harm us by causing fungal infections on skin and hair.

Question 16.
A unique feature in leaves allows them to prepare the food while other parts of plants cannot. Write the possible reason for this. [HOTS]
Answer:
Leaves contain chlorophyll which is essential for food preparation and is absent in other parts of plant.

Question 17.
Algae and fungi form a unique association sharing benefits from each other. What is the name of association between them?
Answer:
Lichens.

Question 18.
In a plant, photosynthesis occurs in a part other than leaf. Name that plant and the part where photosynthesis occurs.
Answer:
Cactus, the part where photosynthesis occurs are stem and branches which are green.

Question 19.
Why is Cuscuta, categorised as a parasite?
Answer:
Cuscuta derives its nutrition using an association where it deprives its host of all valuable nutrients and absorbs them itself. Hence, it is called a parasitic plant.

Question 20.
Plant cannot use the nitrogen present in the soil directly. Why?
Answer:
Plants can use nitrogen only in soluble form while in soil nitrogen is present in inorganic form.

Question 21.
Why are insectivorous plants called partial heterotrophs?
Answer:
Insectivorous plants are autotrophs, i.e. they prepare their own food. They are partial heterotrophs as they eat insects for obtaining nitrogen.

Question 22.
What is the stored food form in sunflower seeds?
Answer:
In sunflower seeds, glucose is stored in the form of oils (fats).

Question 23.
What do you understand by saprotrophic mode of nutrition?
Answer:
The mode of nutrition in which organisms take their nutrients from dead and decaying matter is called saprotrophic mode of nutrition.

Question 24.
A mutually beneficial relationship that occurs between two plants. It is known by what name? Give an example.
Answer:
Symbiosis is the mutually benefitting association between two plants, e.g. lichens.

Question 25.
For testing the presence of starch in leaves, a boiled leaf is used. Why?
Answer:
Boiling the leaf remove chlorophyll/green colour from the leaves.

Question 26.
Mosquitoes, bed bugs, lice and leeches suck our blood. Can they be called as parasites? [HOTS]
Answer:
Yes, these animals/insects are parasites as they harm the hosts while they suck blood.

Question 27.
Insectivorous plants have one or the other specialised organs to catch their prey. What is that organ?
Answer:
Leaves of insectivorous plants catches the prey.

Question 28.
Farmers spread manure of fertilisers in the field or in gardens, etc. Why are these added to the soil?
Answer:
Plants absorb mineral nutrients from soil. Thus, declining their concentration in soil fertilisers and manures enhance or add these essential nutrients back in soil.

Question 29.
A cell is formed of many sub-components. Identify different constituents of the cell. Are animal and plant cells similar?
Answer:
A cell contains nucleus, cytoplasm, vacuole, cell organelles like chloroplast, mitochondria, etc. No, animal cells are different from plant cells.

Question 30.
A goat eats away all the leaves of a small plant (balsam). However, in a few days, new leaves could be seen sprouting in the plant again. How did the plant survive without leaves? [NCERT Exemplar; HOTS]
Answer:
The plant of balsam survived on the food stored in the stem and roots.

Nutrition in Plants Class 7 Science Extra Questions Short Answer Type

Question 1.
Different modes of nutrition has been observed in plants. What are they? Give example of each.
Answer:
Plants show two major modes of nutrition, i.e.
(i) Autotrophs are those which can synthesise their own food.
(ii) Heterotrophs are those which are dependent on other plants and animals for their food. They are of following types:
(a) Parasites, e.g. Cuscuta
(b) Saprotrophs, e.g. fungi.

Question 2.
Sunlight, chlorophyll, carbon dioxide, water and minerals are raw materials essential for photosynthesis. Do you know where they are available? Fill in the blanks with the appropriate raw materials.
(a) Available in the plant: ………
(b) Available in the soil: ………
(c) Available in the air: ………
(d) Available during day : ……… [NCERT Exemplar]
Answer:
(a) Available in the plant: chlorophyll
(b) Available in the soil : water, minerals
(c) Available in the air : carbon dioxide
(d) Available during day : sunlight

Question 3.
Plants are considered an essential part of earth as they keep a check on lot of process occurring all over. What would happen if all the green plants are wiped from earth? [HOTS]
Answer:
Green plants are the source of energy for all the living organisms so that they can perform their normal functions. If all green plants and trees disappear, all the organism depending on them for food and shelter will also die.

The lack of gaseous exchange will lead to increase in amount of CO₂, causing death in humans and other animals also. The cycle of life will gradually disappear.

Question 4.
Autotrophs and heterotrophs are two different organisms with distinct modes of nutrition state. How are they different from each other?
Answer:
The difference between autotrophs and heterotrophs are as follows:

Question 5.
Wheat dough if left in the open, after a few days, starts to emit a foul smell and becomes unfit for use. Give reason. [NCERT Exemplar; HOTS]
Answer:
Carbohydrates in wheat dough encourage the growth of yeast and other saprophytic fungi which breakdown carbohydrates into simpler compounds like CO₂ and alcohol and emit a foul smell.

Question 6.
What are the various raw materials for photosynthesis?
Answer:
Plants utilise carbon dioxide from air and water and minerals are derived from soil (through roots) as raw material for photosynthesis. Besides these chlorophyll present in green leaf is necessary for the process and sunlight is the source of energy which is converted into chemical energy during the process of photosynthesis.

Question 7.
Observe the given figure and label the following terms given in the box. Stomatal opening, guard cell

Question 8.
Nitrogen is an essential nutrient for plants growth. But farmers who cultivate pulses as crops like green gram, bengal gram, black gram, etc., do not apply nitrogenous fertilisers during t cultivation. Why? [NCERT Exemplar; HOTS]
Answer:
Roots of pulses (leguminous plants) have a symbiotic association with a bacterium called Rhizobium. This bacteria convert gaseous nitrogen of air into water soluble nitrogen compounds and give them to the leguminous plants for their growth. Hence, farmers need not use nitrogenous fertilisers.

Question 9.
Pooja is worried about her new shoes which she wore on special occassions that they were spoiled by fungus during rainy season. Is she right to worry, if yes, then tell why does fungi suddenly appears during the rainy season? [HOTS]
Answer:
Yes, the fungi reproduces by spores which are generally present in the air and grow on any article that are left in hot and humid weather for a long time. During rainy season they land on wet and warm things and begin to germinate and grow.

Question 10.
In what unique manner does a pitcher plant derive its nutrition?
Answer:
Nepenthes or pitcher plant modifies its leaf axis into a long tubular pitcher to form a pitfall trap. Inside the pitcher sticky liquid is present. When any insect comes in contact with the leaf, the lid present on it is closed and insect is trapped. The liquid contains digestive enzymes which slowly digest the trapped insects.

Question 11.
Water and minerals are absorbed by the roots and then transported to leaves. How?
Answer:
Water and minerals are transported to the leaves by the vessels which run like pipes throughout the root, stem, branches and the leaves. These vessels are xylem and phloem, forming a continuous path or passage for the nutrients to make them reach the leaf.

Question 12.
Some plants have deep red, violet or brown coloured leaves. Can these leaves perform the photosynthesis process? [HOTS]
Answer:
Yes, plants having deep red, violet or brown coloured leaves can also carry out photosynthesis because they contain chlorophyll. But their green colour of chlorophyll is masked by the large amount of all other coloured pigments.

Question 13.
If plant has a requirement for nitrogen, then from where will they obtain it?
Answer:
Soil contains nitrogen in the form that is not usable by plants. Bacteria like Rhizobium converts nitrogen into soluble form that can be easily used by plants. So, if plant has a requirement for nitrogen, then it will obtain that which the help of bacteria.

Question 14.
In the absence of photosynthesis, life would be impossible on earth. Is it true or false?
Answer:
True, because photosynthesis is important for the existence of life on the earth. Photosynthesis is important process as it is provides food to all living organisms and maintains CO₂ – O₂ balance of nature.

Nutrition in Plants Class 7 Science Extra Questions Long Answer Type

Question 1.
Describe the process by which plants prepare their food using different raw materials.
Answer:
The process by which green plants can prepare their own food is called photosynthesis. Green plants possess chlorophyll in their leaf and utilises carbon dioxide (from air) water, minerals (from soil, through root) as raw material and sunlight as source of energy and convert light energy into chemical energy. The food thus synthesised is in the form of starch (carbohydrate). The overall reaction for photosynthesis can be given as follows:

Question 2.
Describe the method for replinishing the soils with minerals and other essential constituents used by plants growing in those soil by farmers.
Answer:
Replenishment of Nutrients in Soil

Crops require a lot of nitrogen to make proteins. After the harvest, the soil becomes deficient in nitrogen. Plants cannot use the nitrogen gas available in atmosphere directly. Action of certain bacteria can convert this nitrogen into form readily used by plants. Rhizobium bacteria live in the root nodules of leguminous plants. These bacteria take nitrogen gas from the atmosphere and convert it into water soluble nitrogen compounds making it available to the leguminous plants for their growth.

In return, leguminous plants provide food and shelter to the bacteria as Rhizobium cannot prepare its food. They, thus have a symbiotic relationship. This association is very important for the farmers, as they do not need to add nitrogen fertilisers to the soil in which leguminous plants are grown.

Question 3.
Harish went to visit his grandfather in village where he saw that his grandfather’s field of wheat are infected with fungus but no one is aware of this. Harish rushed to his grandfather’s side and told him that the field have been infected with fungi. He should use an antifungal agent in his fields to stop this infection.
(a) What is fungus?
(b) Can fungus only cause diseases or can it be helpful also?
(c) What values are shown by Harish? [Value Based Question]
Answer:
(a) Fungus are saprophytic organisms usually present as spores in atmosphere which can germinate on any substrate in optimal conditions.
(b) Fungus are also useful in that they produce many antibiotics which can cure different types of infections like penicillin.
(c) Harish is sincere, curious and knowledgeable with a keen sense of applying it where necessary.

Question 4.
Wild animals like tiger, wolf, lion and leopard do not eat plants. Does this mean that they can survive without plants? Can you provide a suitable explanation? [HOTS]
Answer:
Animals like tiger, wolf, lion and leopard are carnivores and do not eat plants. They hunt and eat herbivorous animals like deer, gaur, bison, zebra, giraffe, etc., which are dependent on plants for food.

If there are no plants, herbivorous animals will not survive and ultimately animals like tiger, wolf, lion and leopard will have nothing to eat.

Question 5.
Asha went to visit her grandfather in his village. He was having a serious discussion with his fellow members regarding the productivity level of crops for present year. They all were worried about how to increase the productivity of crop Asha listened to this and then suggested to the group that the reason may be decreased level of minerals in soil.
She told her grandfather to plant crops like pulses, gram, beans, etc., for a year then follow with regular crops. This will increase the crop productivity?
(a) What will you name the process suggested by Asha? Why is there decrease in crop productivity?
(b) What are noted benefits of this process? Will the results be as what Asha expressed?
(c) What values are shown by Asha? [Value Based Question]
Answer:
(a) This process is known as crop rotation. All the plants/crops grown in soil use the minerals present in soil for their own use. This continuous usage depletes the concentration of mineral in soil.
(b) After growing leguminous plants, the mineral content of soil is restored and enriched to new level. Yes, the benefit of leguminous plant is the re-enrichment of soil minerals.
(c) Asha is observant, sincere and interested in applying her knowledge to situation