CBSE Science Class 7 Chapter 12 Reproduction in Plants -NCERT Exercise Solutions (Question-Answer) NCERT Exercise Solution (Question-Answer) is given below. Total 10 Questions, all are solved here.
Q1. 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 flower
(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_________________.
(d) The fusion of male and female gametes is termed as _________________.
(e) Seed dispersal takes place by means of ________ , __________ and _____________.
Answer: wind, water, animal
Q2. Describe the different methods of asexual reproduction. Give examples.
Answer: Different methods of asexual reproduction:
(i) Vegetative propagation: It is the method of reproduction in higher plants. In this method, a portion of the plant detaches from the parent plant and develops into an independent plant. Eg. Sugar cane, banana, rose, etc.
(ii) Budding: In budding, reproduction takes place by the formation of small bud-like projection from the body. The nucleus of the parent body divides into two and one of the nuclei moves into the bud. When the bud mature, it detaches from the parent and can exist independently. Eg. Hydra and yeast.
(iii) Spore formation: During unfavourable climatic conditions such as scarcity of water, food, heat or dryness, the plants produce spores. The spore is a small single-celled reproductive body which is covered by a thick and hard protective coating. This protective helps to survive in an unfavourable condition. When the condition become favourable, the thick coating breaks open and spores germinate to produce a new plant. Eg. Bead mould, fungi etc.
(iv) Fragmentation: Fragmentation is the process where a mature organism breaks up into small pieces. Each of these pieces can lead an independent life like a new individual. Eg. Algae
(v) Binary fission: In this process, a mature cell gives rise to two or more daughter cells. During this process, the nucleus divides first followed by the division of cytoplasm. Eg. Amoeba, paramecium, etc.
Q3. Explain what you understand by sexual reproduction.
Answer: In sexual reproduction, two-parent involve, males and females which produce male and female gametes. In plants, sexual reproduction takes place through the flower. The flower is the reproductive part of the plant.
Stamen is the male reproductive part of flower and pistil is the female reproductive parts of the flower.
The fusion of male and female reproductive cells forms a single cell called a zygote. The zygote gradually develops into a seed from which a new plant grows.
Through this process, new organisms are products which are almost similar to their parents.
Q4. State the main difference between asexual and sexual reproduction.
Answer: Difference between sexual and asexual reproduction:
|SEXUAL REPRODUCTION||ASEXUAL REPRODUCTION|
|Only one parent is involved.||It involves two parents i.e. male and female|
|It occurs in unisexual plant.||It occurs in bisexual plant.|
|Characteristics of only one parent is inherited.||Characteristics of both parents are inherited.|
|Fertilisation or gamete formation are not seen.||Fertilisation of gamete forms single cell called zygote.|
|Reproductive organs are not present.||Fully developed reproductive organs are present.|
Q5. Sketch the reproductive parts of a flower.
Answer: attach fig from book.
Q6. Explain the difference between self-pollination and cross-pollination.
Answer: Difference between self-pollination and cross pollination:
|SELF POLLINATION||CROSS POLLINATION|
|When the pollen grains of one flower are transferred to the stigma of the same flower, it is called self-pollination.||When the pollen grains of one flower are transferred to the stigma of another flower of the same species, it is called cross-pollination.|
Q7. How does the process of fertilisation take place in flowers?
Answer: After pollination, the stigma secretes a sugary, sticky fluid which helps the pollen grains to grow. The pollen grains produce a thin tube that grows through the style and reaches one of the ovules present in the ovary.
The tube dissolves the wall of the ovule and discharges two male gametes in it.
One of the male gametes fuses with the egg present on ovule. The process of fusion of male and female gametes is called fertilization. It results in the formation of zygote.
Attach fig from book:
Q8. Describe the various ways by which seeds are dispersed.
Answer: The scattering of seeds along with fruits is called dispersal. The dispersal of seeds and fruits takes place in the following ways:
(i) Dispersal by the wind: The seeds which are small, light in weight and have tufts of hair or wings are carried away to distant places by the wind. Eg. Seeds of sunflower, cotton, etc.
(ii) Dispersal by water: Fruits and seeds having special structures such as spongy outer coat are dispersed by water. Eg. Seeds and fruits of water lily, lotus, etc.
(iii) Dispersal by animals: Seeds and fruits which are edible or have hooks, stiff hairs, spines, bristles are dispersed by animals. Such seeds stick to the skin or fur of animals or clothes of human beings and are carried to distant places.
(iv) Dispersion by explosion: When the fruit ripens, seeds grow in size, thus splitting the fruit into two halves with a small explosion. It leads to the dispersion of seeds. Eg. Fruits like pes, mustard, etc.
Q9. 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|
|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|
Q10. Tick () the correct answer:
(a) The reproductive part of a plant is the
Answer: (iv) flower
(b) The process of fusion of the male and the female gametes is called
(iv) seed formation
Answer: (i) fertilisation
(c) Mature ovary forms the
Answer: (iv) fruit
(d) A spore reproducing organism is
(ii) bread mould
Answer: (ii) bread mould
(e) Bryophyllum can reproduce by its
Answer: (ii) leaves
Science Class 7 Chapter 12 Reproduction in Plants – NCERT Exercise Solutions (Question-Answer) ended here.👍👍👍