NCERT Solutions for Class 7 Science Chapter 12 Reproduction in Plants

1. Fill in the blanks:

(a) Production of new individuals from the vegetative part of parent is called_____________.

Answer: vegetative reproduction

(b) A flower may have either male or female reproductive parts. Such a flower is called_____________.

Answer: unisexual

(c) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as _____________.

Answer: pollination

(d) The fusion of male and female gametes is termed as _____________.

Answer: fertilisation

(e) Seed dispersal takes place by means of _____________,_____________ and _____________.

Answer: wind, water, animals

2. Describe the different methods of asexual reproduction. Give examples.

Answer: Asexual reproduction is carried out by following methods –

• Vegetative reproduction: In vegetative reproduction, reproduction is carried out from vegetative parts like stem, roots, buds and leaves. This type of reproduction is found in ginger, potato, bryophyllum, etc.
• Budding: Generation of new organism through bulb like outgrowth called bud, and this process is called budding. The bud grows on the parent body, and after complete growth it detaches from the parent body, thereby, forming new individual. This type of reproduction is generally found in yeast.
• Fragmentation: In this type of reproduction, parent breaks into two or more fragment, which ultimately develops to form new individual. It is found in spirogyra and algae.
• Spore formation: spores are tiny rounded structures protected by thick wall. When spores comes in contact with moisture they germinate to form new individual.

3. Explain what you understand by sexual reproduction.

Answer: Sexual reproduction occurs when male and female gamete fuse with each other. It requires two parents. In plants, this functioning is generally carried out by flower. Flowers produce seeds, which germinate new into new individual. New individual formed is similar to that of parents.

4. State the main difference between asexual and sexual reproduction.

Answer:

Asexual reproduction	Sexual reproduction
One parent is required for reproduction	Two parents are required for reproduction
New plants formed are identical to parent	New plants formed are not identical to parents
Reproductive parts are not required	Reproductive part in plant is necessary. Flower is reproductive parts containing sexual organs.
Process of fertilization is absent	Fertilization takes place to form zygote
Formation of seeds is not needed	Seed formation is needed
Asexual reproduction is found in potato, spirogyra, yeast, etc	Sexual reproduction is found in Hibiscus, sunflower, etc

5. Sketch the reproductive parts of a flower.

Answer:

6. Explain the difference between self-pollination and cross-pollination.

Answer:

Self Pollination	Cross Pollination
Pollen is transferred from stamen to pistil in same flower	Pollen is transferred from stamen of one flower to pistil of another flower of same plant or different plant of same type
Found in bisexual flowers	Found in unisexual as well as bisexual flowers
E.g. wheat, rice, etc	E.g. coconut, ladyfinger, tomato, etc

7. How does the process of fertilisation take place in flowers?

Answer: After the arrival of pollen on stigma, it germinates forming a pollen tube. Pollen tube reaches ovary of pistil through style. Pollen tube releases male gametes at ovule. Here, fertilisation occurs forming zygote. Zygote divides and redivides, thereby forming embryo in the seed.

8. Describe the various ways by which seeds are dispersed.

Answer: Dispersal of seeds takes place through various medium like wind, water, animals and explosion. Seeds of smaller in size gets dispersed by wind. In general, these seeds have wings or hairs present on it, for example seed of drumstick and sunflower. Plants living near water or inside water have seeds, which floats on water or gets carried away through water. For example, coconuts floats and gets dispersed using water. Seed dispersal by animals takes place, when animals eat fruits, and excrete seeds. Many times seeds, clings to animals body and gets carried away with them. E.g. xanthium. Bursting of fruits leads to dispersal of seeds. This is explosion medium of dispersal. By this methods seeds spreads at long distance from the plant.

9. Match items in Column I with those in Column II:

Column I	Column II
(a) Bud	(i) Maple
(b) Eyes	(ii) Spirogyra
(c) Fragmentation	(iii) Yeast
(d) Wings	(iv) Bread mould
(e) Spores	(v) Potato
	(vi) Rose

Answer:

Column I	Column II
(a) Bud	(iii) Yeast
(b) Eyes	(v) Potato
(c) Fragmentation	(ii) Spirogyra
(d) Wings	(i) Maple
(e) Spores	(iv) Bread mould

10. Tick the correct answer:

(a) The reproductive part of a plant is the – (i) leaf (ii) stem (iii) root (iv) flower

Answer: (iv) flower

(b) The process of fusion of the male and the female gametes is called – (i) fertilisation (ii) pollination (iii) reproduction (iv) seed formation

Answer: (i) fertilisation

(c) Mature ovary forms the – (i) seed (ii) stame (iii) pistil (iv) fruit

Answer: (iv) fruit

(d) A spore producing organism is – (i) rose (ii) bread mould (iii) potato (iv) ginger

Answer: (ii) bread mould

(e) Bryophyllum can reproduce by its – (i) stem (ii) leaves (iii) roots (iv) flower

Answer: (ii) leaves

Check other lessons NCERT Solutions for Class 7

Download free NCERT textbook class 7 Science – Chapter 12 Reproduction in Plants