NCERT Solutions for Class 7 Science Chapter 8 Reproduction in Plants

NCERT
SOLUTIONS
CLASS - 7TH

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Book : Science Ncert Solutions | Chapter-12 Science

Class : 7th
Subject : Science
Chapter : 12
Chapter Name : Reproduction In Plants

Q1 Fill in the blanks:
(a) Production of new individuals from the vegetative part of parent is called_____________.
(b) A ower may have either male or female reproductive parts. Such a ower is called_____________.
(c) The transfer of pollen grains from the anther to the stigma of the same or of another ower 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. (a) Production of new individuals from the vegetative part of parent is called vegetative
propagation.
(b) A ower may have either male or female reproductive parts. Such a ower is called unisexual.
(c) The transfer of pollen grains from the anther to the stigma of the same or of another ower of the same
kind is known as pollination.
(d) The fusion of male and female gametes is termed as fertilisation.
(e) Seed dispersal takes place by means of wind , water and animals.

Q2 Describe the different methods of asexual reproduction. Give examples.

Answer. The various modes of asexual reproduction in plants are as follows:
(i) Vegetative propagation: It is the ability of a plant to produce new plants from roots, stems, leaves, and
buds. Vegetative propagation is divided into two types.

Natural vegetative propagation: This type of vegetative propagation occurs easily in nature and
involves simple vegetative parts. Potato plant sprouting from an eye is a common example.

Arti cial vegetative propagation: This type of vegetative propagation is performed manually and
generally occurs in laboratory conditions. The formation of a complete plant from a stem cutting of
rose is a common example of this method.

(ii)Budding:lt involves the formation of a new individual from a bulb-like projection called a bud. The bud
grows and gets detached from the parent to form a new individual. It is commonly observed in yeast.
(iii)Fragmentation:It is a form of asexual reproduction where a new organism is formed from the fragments
of the parent body. It is the only mode of asexual reproduction in Spirogyra.
(iv)Spore formation:Many non- owering plants reproduce through spore formation. Spores are tiny cells
protected by a thick wall. Fungi such as bread moulds reproduce asexually using this method.

Q3 Explain what you understand by sexual reproduction.

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Book : Science Ncert Solutions | Chapter-12 Science

Answer. Sexual reproduction is a process which involves production of seeds. It requires two parents. Most
plants reproduce sexually with the help of owers. The main function of a ower is to reproduce and
therefore develop new seeds that can grow into new plants.

Q4 State the main difference between asexual and sexual reproduction.

Answer. Difference between asexual and sexual reproduction.

Q5 Sketch the reproductive parts of a ower.

Answer.

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Q6 Explain the difference between self-pollination and cross-pollination.

Answer. Difference between self-pollination and cross-pollination.

Q7 How does the process of fertilisation take place in owers?

Answer. When pollen lands on stigma, it germinates and gives rise to a pollen tube that
passes through the style and reaches the ovary of a pistil. When the pollen tube reaches an ovule, it releases
the male gametes. A male gamete fuses with a female gamete in the ovule. This process is known as
fertilisation. The cell which is formed after the fusion of a male and a female gamete is known as zygote.
This zygote divides several times in order to form the embryo present inside the seed.

Process of fertilisation

Q8 Describe the various ways by which seeds are dispersed.

Answer. Seed dispersal occurs by the following agencies.
(a)Dispersal by animals - There are many ways by which birds and animals can disperse seeds. For example,
birds and animals can eat the fruits and excrete the seeds away from the parent plant. Some seeds have
barbs or other structures that get attached to the animal's body and are carried to new sites. Some fruits
have hooks on them which cling to fur or clothes.

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(b)Dispersal by wind- Seeds that get dispersed by wind are usually smaller in size or they have wings or hair-
like structures. For example, winged seeds of drumsticks, hairy fruit of sun ower, etc. are dispersed by wind.
(c)Dispersal by water — Many aquatic plants or plants that live near water has seeds that can oat and are
carried away by water. For example, coconuts can oat and are dispersed by water.
(d) Dispersal by explosion — Sometimes the seeds are dispersed by the bursting of fruits with sudden jerks.
The seeds get scattered or distributed far from the parent plant. Examples of such plants are castor and
balsam.

Q9 Match items in Column I with those in Column II:

Answer.

Q10 Tick ( ) the correct answer:
(a) The reproductive part of a plant is the
(i) leaf
(ii) stem
(iii) root
(iv) ower
(b) The process of fusion of the male and female gametes is called
(i) fertilisation
(ii) pollination
(iii) reproduction
(iv) seed formation
(c) Mature ovary forms the

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(i) seed
(ii) stamen
(iii) pistil
(iv) fruit
(d) A spore producing plant is
(i) rose
(ii) bread mould
(iii) potato
(iv) ginger
(e) Bryophyllum can reproduce by its
(i) stem
(ii) leaves
(iii) roots
(iv) ower

Answer (a) The reproductive part of a plant is the
(iv) ower
(b) The process of fusion of the male and female gametes is called
(i) fertilisation
(c) Mature ovary forms the
(iv) fruit
(d) A spore producing Plant is
(ii) bread mould
(e) Bryophyllum can reproduce by its
(ii) leaves

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