1. Which among the following is a unicellular organism that reproduces by budding:

(a) Hydra

(b) Planaria

(c) Yeast

(d) Spirogyra

Answer. (c) Spirogyra

Answer : Yeast is a unicellular organism which reproduces by budding. Spirogyra reproduces by fragmentation; planaria reproduces by regeneration and; hydra (a multicellular organism) reproduces by budding.

2. Which among the following does not reproduce by spore formation:

(a) Penicillium fungus

(b) Yeast fungus

(c) Mucor fungus

(d) Rhizopus fungus

Answer. (b) Yeast fungus

In spore formation method structures called sporangia produces tiny cells called spores. when the spores come in contact with a moist surface , it develops into new individual. example – rhizopus , mucor , penicilium etc. AMOEBA , PARAMAECIUM , PLASMODIUM , YEAST , HYDRA SPYROGYRA ARE NOT PRODUCED BY SPORE FORMATION.

3. The rapid spreading of bread mould on slices of bread are due to:

(i) Presence of large number of spores in air

(ii) Presence of large number of thread-like branched hyphae

(iii) Presence of moisture and nutrients

(iv) Formation of round shaped sporangia

(a) (i) and (iii)

(b) (ii) and (iv)

(c) (i) and (ii)

(d) (iii) and (iv)

Answer. (a) (i) and (iii)

4. The asexual reproduction in the Spirogyra involves:

(a) Breaking up of filaments into smaller bits

(b) Division of a cell into many cells

(c) Division of a cell into two cells

(d) Formation of a large number of buds

Answer. (b) Division of a cell into many cells

Explanation: In spirogyra, asexual reproduction takes place through the process of fragmentation. Spirogyra, a filamentous alga, breaks down its filament into smaller parts, which will grow completely to form a new organism.

5. Reason for the greater similarities among the offsprings produced by asexual reproduction, is:

(i) Asexual reproduction involves only one parent

(ii) Asexual reproduction involves two parents

(iii) Asexual reproduction involves gametes

(iv) Asexual reproduction does not involve gametes

(a) (i) and (ii)

(b) (i) and (iii)

(c) (ii) and (iv)

(d) (i) and (iv)

Answer. (d) (i) and (iv)

6. The process of the division of cell into several cells during reproduction in Plasmodium is termed as:

(a) Fragmentation

(b) Budding

(c) Multiple fission

(d) Binary fission

Answer. (c) Multiple fission

Binary fission is a form of asexual reproduction and cell division where the cell divides into two separate cells.
Budding is a form of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site.
Fragmentation is a form of asexual reproduction in which an organism is split into fragments.
Multiple fission is the process where the nucleus divides into a number of daughter nuclei followed by the division of the cell body into an equal number of parts. This kind of division takes place in Plasmodium.
Thus, the correct answer is option (C), ‘Multiple fission’

7. The number of chromosomes in parents and offsprings of a particular species remains constant due to:

(a) Doubling of chromosomes after zygote formation

(b) Halving of chromosomes during gamete formation

(c) Doubling of chromosomes after gamete formation

(d) Halving of chromosomes after gamete formation

Answer. (b) Halving of chromosomes during gamete formation

Answer: (b) The number of chromosomes in parents and offsprings of a particular species remains constant due to halving of chromosome during gamete formation. The gametes are special type of cells which contain only half the amount of DNA as compared to normal cells of an organism.

8. A Planaria worm is cut horizontally in the middle into two halves P and Q such that the part P contains the whole head of the worm. Another Planaria worm is cut vertically into two halves R and S in such a way that both the cut pieces R and S contain half head each. Which of the cut pieces of the two Planaria worms could regenerate to form the complete respective worms?

(a) Only P

(b) Only R and S

(c) P, Rand S

(d) P, Q, R and S

Answer. (d) P, Q, R and S

In Planaria, each body piece can regenerate into a full, new organism.

9. The number of chromosomes in both parents and offsprings of a particular species remains constant because:
(a) Chromosomes get doubled after zygote formation

(b) Chromosomes get doubled after gamete formation

(c) Chromosomes get halved during gamete formation

(d) Chromosomes get halved after gamete formation

Answer. (c) Chromosomes get halved during gamete formation

Explanation: The number of chromosomes in parents and offsprings of a particular species remains constant due to the halving of chromosomes under the meiosis process during gamete formation.

10. The figure given alongside shows the human male reproductive organs. Which structures make sperms and seminal fluid?

(a) V makes sperms and X makes seminal fluid

(b) W makes sperms and Y makes seminal fluid

(c) X makes sperms and W makes seminal fluid

(d) Y makes sperms and V makes seminal fluid

Answer. (d) Y makes sperms and V makes seminal fluid

Y represents the testes that produce sperms and V represents the prostate gland that produces seminal fluid.

11. An organism capable of reproducing by two asexual reproduction methods one similar to the reproduction in yeast and the other similar to the reproduction in Planaria is:

(a) Spirogyra

(b) Hydra

(c) Bryophyllum

(d) Paramecium

Answer. (b) Hydra

Hydra can reproduce by the method of budding similar to yeast, and also by regeneration as in the case of Planaria.

12. Among the following select the statements that are true regarding the sexual reproduction in flowering plants?

(i) Fertilisation is a compulsory event

(ii) It always results in the formation of zygote

(iii) Offsprings formed are clones

(iv) It requires two types of gametes

(a) (i) nad (iv)

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

(c) (i), (ii) and (iv)

(d) (ii), (iii) and (iv)

Answer. (c) (i), (ii) and (iv)

13. Which among the following are not the functions of testes at puberty?

(i) Formation of germ cells

(ii) Secretion of testosterone

(iii) Development of placenta

(iv) Secretion of estrogen

(a) (i) and (ii)

(b) (i) and (iii)

(c) (ii) and (iv)

(d) (iii) and (iv)

Answer. (d) (iii) and (iv)

14. Which out of the following processes does not lead to the formation of clones:

(a) Fertilisation

(b) Fission

(c) Tissue culture

(d) Fragmentation

Answer. (a) Fertilisation

Fertilisation is the fusion of two gametes in a sexual reproduction. It produces genetically different offsprings and does not lead to the formation of clones.

15. The ratio of number of chromosomes in a human zygote and a human sperm is:

(a) 2 : 1

(b) 3 : 1

(c) 1 : 2

(d) 1 : 3

Answer. (a) 2 : 1

Therefore, 23 chromosomes (sperm cell, n) + 23 chromosomes (egg cell, n) = 46 chromosomes (zygote); or 23 pair of chromosomes (zygote, 2n). The answer is 2:1

Important Link

Quick Revision Notes : How do Organisms Reproduce

NCERT Solution : How do Organisms Reproduce

IMPORTANT QUESTION : How do Organisms Reproduce

Click here for Free Video Lectures