NCERT Solutions for Class 7 Science, Chapter 12 - Reproduction in Plants is available here. This chapter is also available here for download in PDF format. Download link is given at the end of this article.
NCERT Solutions for Class 7 Science, Chapter 12 - Reproduction in Plants:
Question1. Fill in the blanks:
(a) Production of new individuals from the vegetative part of parent is called_____________.
(b) A flower may have either male or female reproductive parts. Such a flower is called_____________.
(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 _____________.
wind, water, animals
Question2. Describe the different methods of asexual reproduction. Give examples.
Different methods of asexual production are:
Vegetative propagation: It is a type of asexual reproduction in which new plants are produced from
roots, stems, leaves and buds. Since reproduction is through the vegetative parts of the plant.
Budding: In this process, a new individual from a bulb-like projection, bud, grows and gets detached from the parent to form a new individual and it is mostly observed in yeast.
Spore formation: Spores are asexual reproductive bodies. A spore is covered by a hard protective coat to withstand unfavourable conditions such as high temperature & ow humidity. So they can survive for a long time. Under favourable conditions, a spore germinates and develops into a new
individual. Fungi on bread and plants such as moss and ferns reproduce through spores.
Fragmentation: In this process, a new organism is developed from the fragments of the parent body. Example, An alga breaks up into two or more fragments. These fragments or pieces grow into new individuals
Question3. Explain what you understand by sexual reproduction.
It is the mode of reproduction in which male & female gamete fuse together to form a zygote. The zygote gradually divides to form a new organism.
Question4. State the main difference between asexual and sexual reproduction.
Difference between asexual and sexual reproduction:
In this process, two parents are involved.
In this process, a single parent is involved.
Sexual reproduction involves the fusion of male and female gametes.
In asexual reproduction, plants can give rise to new plants without seeds.
Question5. Sketch the reproductive parts of a flower.
Question6. Explain the difference between self-pollination and cross-pollination.
In self-pollination, pollen grains are transferred from the anther to the stigma of the same flower.
In cross-pollination, pollen grains are transferred from the anther of one flower to the stigma of another flower of the same kind.
Question7. How does the process of fertilisation take place in flowers?
As soon as pollen lands of the stigma, it germinated & yields a pollen tube that passes through the style and enters the ovary of a pistil. As the pollen tube enters an ovule, it releases the male gametes. A male gamete fuses with a female gamete in the ovule by a process known as fertilization. The cell formed after the fusion of a female and a male gamete is termes as a zygote. This zygote splits numerous times form the embryo present inside the seed. In this way, the process of fertilisation takes place in flowers.
Question8. Describe the various ways by which seeds are dispersed.
Seed dispersal is aided by the wind, water and animals. Sees also dispersed when fruits burst with sudden jerks.
By wind: Seeds and fruits of plants are carried away by the wind, water and animals. Winged seeds such as those of drumstick and maple, light seeds of grasses or hairy seeds of aak (Madar) and hairy fruit of the sunflower, get blown off with the wind to faraway places.
By water: Seeds of aquatic plants or plants near water bodies usually develop floating ability in the form of a spongy or fibrous outer coat as in coconut and get dispersed by water.
By animals: Spiny seeds with hooks which get attached to the bodies of animals and are carried to distant places.
Dispersion of seeds by bursting of fruits: Some seeds are dispersed when the fruits burst with sudden jerks. The seeds are scattered far from the parent plant. This happens in the case of castor and balsam.
Question9. 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
Question10. Tick (√) the correct answer:
(a) The reproductive part of a plant is the
Flower is the reproductive part of a plant. So, option (iv) is correct.
(b) The process of fusion of the male and the female gametes is called
(iv) seed formation
Option (i) fertilisation, is the correct option.
(c) Mature ovary forms the
Option (iv) fruit, is the correct option.
(d) A spore producing organism is
(ii) bread mould
Option (ii) bread mould is the correct option.
(e) Bryophyllum can reproduce by its
Option (ii) leaves is the correct option.