NCERT Textbook: Reproduction in Plants | Science Class 7 PDF Download

 Page 1


Reproduction in Plants
8
T
o produce its kind is a
characteristic of all living
organisms. You have already
learnt this in Class VI. The production
of new individuals from their parents is
known as reproduction. But, how do
plants reproduce? There are different
modes of reproduction in plants which
we shall learn in this chapter.
8.1 MODES OF REPRODUCTION
In Class VI you learnt about different
parts of a flowering plant. Try to list the
various parts of a plant and write the
functions of each. Most plants have
roots, stems and leaves. These are called
the vegetative parts of a plant. After a
certain period of growth, most plants
bear flowers. You may have seen the
mango trees flowering in spring. It is
these flowers that give rise to juicy
mango fruit we enjoy in summer. We eat
the fruits and usually discard the seeds.
Seeds germinate and form new plants.
So, what is the function of flowers in
plants? Flowers perform the function of
reproduction in plants. Flowers are the
reproductive parts.
There are several ways by which
plants produce their offspring. These are
categorised into two types: (i) asexual,
and (ii) sexual reproduction. In asexual
reproduction plants can give rise to new
plants without seeds, whereas in sexual
Asexual reproduction
In asexual reproduction new plants are
obtained without production of seeds.
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, it is known as
vegetative propagation.
Activity 8.1
Cut a branch of rose or champa with a
node. This piece of branch is termed a
cutting. Bury the cutting in the soil. A
node is a part of the stem/branch at
which a leaf arises (Fig. 8.1). Water the
cutting every day and observe its
growth. Observe and record the number
of days taken for roots to come out and
Paheli thought that new
plants always grow from seeds.
But, she has never seen the seeds
of sugarcane, potato and rose. She
wants to know how these plants
reproduce.
reproduction, new plants are obtained
from seeds.
Reprint 2024-25
Page 2


Reproduction in Plants
8
T
o produce its kind is a
characteristic of all living
organisms. You have already
learnt this in Class VI. The production
of new individuals from their parents is
known as reproduction. But, how do
plants reproduce? There are different
modes of reproduction in plants which
we shall learn in this chapter.
8.1 MODES OF REPRODUCTION
In Class VI you learnt about different
parts of a flowering plant. Try to list the
various parts of a plant and write the
functions of each. Most plants have
roots, stems and leaves. These are called
the vegetative parts of a plant. After a
certain period of growth, most plants
bear flowers. You may have seen the
mango trees flowering in spring. It is
these flowers that give rise to juicy
mango fruit we enjoy in summer. We eat
the fruits and usually discard the seeds.
Seeds germinate and form new plants.
So, what is the function of flowers in
plants? Flowers perform the function of
reproduction in plants. Flowers are the
reproductive parts.
There are several ways by which
plants produce their offspring. These are
categorised into two types: (i) asexual,
and (ii) sexual reproduction. In asexual
reproduction plants can give rise to new
plants without seeds, whereas in sexual
Asexual reproduction
In asexual reproduction new plants are
obtained without production of seeds.
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, it is known as
vegetative propagation.
Activity 8.1
Cut a branch of rose or champa with a
node. This piece of branch is termed a
cutting. Bury the cutting in the soil. A
node is a part of the stem/branch at
which a leaf arises (Fig. 8.1). Water the
cutting every day and observe its
growth. Observe and record the number
of days taken for roots to come out and
Paheli thought that new
plants always grow from seeds.
But, she has never seen the seeds
of sugarcane, potato and rose. She
wants to know how these plants
reproduce.
reproduction, new plants are obtained
from seeds.
Reprint 2024-25
REPRODUCTION IN PLANTS 83
new leaves to arise. Try the same activity
by growing money plant in a jar of water
and record your observations.
Likewise you can also grow ginger
(Fig. 8.3) or turmeric.
Bryophyllum (sprout leaf plant) has
buds in the margins of leaves (Fig. 8.4).
If a leaf of this plant falls on a moist
You must have seen flower buds
developing into flowers. Apart from
flower buds, there are buds in the axil
(point of attachment of the leaf at the
node) of leaves which develop into
shoots. These buds are called vegetative
buds (Fig. 8.2). A bud consists of a short
stem around which immature
overlapping leaves are present. Vegetative
buds can also give rise to new plants.
Activity 8.2
Take a fresh potato. Observe the scars
on it with the help of a magnifying glass.
You may find bud(s) in them. These scars
are also called “eyes”. Cut the potato
into small portions, each with an eye
and bury them in the soil. Water the
pieces regularly for a few days and
observe their progress. What do you find?
Fig. 8.1  Stem-cutting of rose
Fig. 8.2  Potato plant sprouting from an ‘eye’
Fig. 8.3  Ginger with new plants sprouting
from it
soil, each bud can give rise to a new
plant.
Roots of some plants can also give
rise to new plants. Sweet potato and
dahlia are examples.
Plants such as cacti produce new
plants when their parts get detached
Node
Bud in
the axil
Reprint 2024-25
Page 3


Reproduction in Plants
8
T
o produce its kind is a
characteristic of all living
organisms. You have already
learnt this in Class VI. The production
of new individuals from their parents is
known as reproduction. But, how do
plants reproduce? There are different
modes of reproduction in plants which
we shall learn in this chapter.
8.1 MODES OF REPRODUCTION
In Class VI you learnt about different
parts of a flowering plant. Try to list the
various parts of a plant and write the
functions of each. Most plants have
roots, stems and leaves. These are called
the vegetative parts of a plant. After a
certain period of growth, most plants
bear flowers. You may have seen the
mango trees flowering in spring. It is
these flowers that give rise to juicy
mango fruit we enjoy in summer. We eat
the fruits and usually discard the seeds.
Seeds germinate and form new plants.
So, what is the function of flowers in
plants? Flowers perform the function of
reproduction in plants. Flowers are the
reproductive parts.
There are several ways by which
plants produce their offspring. These are
categorised into two types: (i) asexual,
and (ii) sexual reproduction. In asexual
reproduction plants can give rise to new
plants without seeds, whereas in sexual
Asexual reproduction
In asexual reproduction new plants are
obtained without production of seeds.
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, it is known as
vegetative propagation.
Activity 8.1
Cut a branch of rose or champa with a
node. This piece of branch is termed a
cutting. Bury the cutting in the soil. A
node is a part of the stem/branch at
which a leaf arises (Fig. 8.1). Water the
cutting every day and observe its
growth. Observe and record the number
of days taken for roots to come out and
Paheli thought that new
plants always grow from seeds.
But, she has never seen the seeds
of sugarcane, potato and rose. She
wants to know how these plants
reproduce.
reproduction, new plants are obtained
from seeds.
Reprint 2024-25
REPRODUCTION IN PLANTS 83
new leaves to arise. Try the same activity
by growing money plant in a jar of water
and record your observations.
Likewise you can also grow ginger
(Fig. 8.3) or turmeric.
Bryophyllum (sprout leaf plant) has
buds in the margins of leaves (Fig. 8.4).
If a leaf of this plant falls on a moist
You must have seen flower buds
developing into flowers. Apart from
flower buds, there are buds in the axil
(point of attachment of the leaf at the
node) of leaves which develop into
shoots. These buds are called vegetative
buds (Fig. 8.2). A bud consists of a short
stem around which immature
overlapping leaves are present. Vegetative
buds can also give rise to new plants.
Activity 8.2
Take a fresh potato. Observe the scars
on it with the help of a magnifying glass.
You may find bud(s) in them. These scars
are also called “eyes”. Cut the potato
into small portions, each with an eye
and bury them in the soil. Water the
pieces regularly for a few days and
observe their progress. What do you find?
Fig. 8.1  Stem-cutting of rose
Fig. 8.2  Potato plant sprouting from an ‘eye’
Fig. 8.3  Ginger with new plants sprouting
from it
soil, each bud can give rise to a new
plant.
Roots of some plants can also give
rise to new plants. Sweet potato and
dahlia are examples.
Plants such as cacti produce new
plants when their parts get detached
Node
Bud in
the axil
Reprint 2024-25
SCIENCE 84
Activity 8.3
(To be demonstrated by the teacher)
Take a piece of yeast cake or yeast
powder  from a bakery or a chemist shop.
Take a pinch of yeast and place it in a
container with some water. Add a
spoonful of sugar and shake to dissolve
it. Keep it in the warm part of a room.
After an hour, put a drop of this liquid
on a glass slide and observe under a
microscope. What do you observe? You
may see the formation of new yeast cells
(Fig. 8.5).
from the main plant body. Each
detached part can grow into a new
plant.
Fig. 8.4  Leaf of Bryophyllum with buds in the
margin
Boojho wants to know if
there is any advantage of
vegetative propagation.
Plants produced by vegetative
propagation take less time to grow and
bear flowers and fruits earlier than those
produced from seeds. The new plants
are exact copies of the parent plant, as
they are produced from a single parent.
Later in this chapter you will learn
that plants produced by sexual
reproduction have characters of both the
parents. Plants produce seeds as a result
of sexual reproduction.
Budding
You have already learnt about the tiny
organisms like yeast can be seen only
under a microscope. These grow and
multiply every few hours if sufficient
nutrients are made available to them.
Remember that yeast is a single-celled
organism. Let us see how they
reproduce?
The small bulb-like projection
coming out from the yeast cell is called
a bud. The bud gradually grows and
gets detached from the parent cell and
forms a new yeast cell. The new yeast
cell grows, matures and produces more
yeast cells. Sometimes, another  bud
arises from the bud forming a chain of
buds. If this process continues, a large
number of yeast cells are produced in a
short time.
Fragmentation
You might have seen slimy green
patches in ponds, or in other stagnant
water bodies. These are the algae. When
Fig. 8.5  Reproduction in yeast by budding
Yeast cell
Developing bud
Chain of buds
New bud
New plants
Reprint 2024-25
Page 4


Reproduction in Plants
8
T
o produce its kind is a
characteristic of all living
organisms. You have already
learnt this in Class VI. The production
of new individuals from their parents is
known as reproduction. But, how do
plants reproduce? There are different
modes of reproduction in plants which
we shall learn in this chapter.
8.1 MODES OF REPRODUCTION
In Class VI you learnt about different
parts of a flowering plant. Try to list the
various parts of a plant and write the
functions of each. Most plants have
roots, stems and leaves. These are called
the vegetative parts of a plant. After a
certain period of growth, most plants
bear flowers. You may have seen the
mango trees flowering in spring. It is
these flowers that give rise to juicy
mango fruit we enjoy in summer. We eat
the fruits and usually discard the seeds.
Seeds germinate and form new plants.
So, what is the function of flowers in
plants? Flowers perform the function of
reproduction in plants. Flowers are the
reproductive parts.
There are several ways by which
plants produce their offspring. These are
categorised into two types: (i) asexual,
and (ii) sexual reproduction. In asexual
reproduction plants can give rise to new
plants without seeds, whereas in sexual
Asexual reproduction
In asexual reproduction new plants are
obtained without production of seeds.
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, it is known as
vegetative propagation.
Activity 8.1
Cut a branch of rose or champa with a
node. This piece of branch is termed a
cutting. Bury the cutting in the soil. A
node is a part of the stem/branch at
which a leaf arises (Fig. 8.1). Water the
cutting every day and observe its
growth. Observe and record the number
of days taken for roots to come out and
Paheli thought that new
plants always grow from seeds.
But, she has never seen the seeds
of sugarcane, potato and rose. She
wants to know how these plants
reproduce.
reproduction, new plants are obtained
from seeds.
Reprint 2024-25
REPRODUCTION IN PLANTS 83
new leaves to arise. Try the same activity
by growing money plant in a jar of water
and record your observations.
Likewise you can also grow ginger
(Fig. 8.3) or turmeric.
Bryophyllum (sprout leaf plant) has
buds in the margins of leaves (Fig. 8.4).
If a leaf of this plant falls on a moist
You must have seen flower buds
developing into flowers. Apart from
flower buds, there are buds in the axil
(point of attachment of the leaf at the
node) of leaves which develop into
shoots. These buds are called vegetative
buds (Fig. 8.2). A bud consists of a short
stem around which immature
overlapping leaves are present. Vegetative
buds can also give rise to new plants.
Activity 8.2
Take a fresh potato. Observe the scars
on it with the help of a magnifying glass.
You may find bud(s) in them. These scars
are also called “eyes”. Cut the potato
into small portions, each with an eye
and bury them in the soil. Water the
pieces regularly for a few days and
observe their progress. What do you find?
Fig. 8.1  Stem-cutting of rose
Fig. 8.2  Potato plant sprouting from an ‘eye’
Fig. 8.3  Ginger with new plants sprouting
from it
soil, each bud can give rise to a new
plant.
Roots of some plants can also give
rise to new plants. Sweet potato and
dahlia are examples.
Plants such as cacti produce new
plants when their parts get detached
Node
Bud in
the axil
Reprint 2024-25
SCIENCE 84
Activity 8.3
(To be demonstrated by the teacher)
Take a piece of yeast cake or yeast
powder  from a bakery or a chemist shop.
Take a pinch of yeast and place it in a
container with some water. Add a
spoonful of sugar and shake to dissolve
it. Keep it in the warm part of a room.
After an hour, put a drop of this liquid
on a glass slide and observe under a
microscope. What do you observe? You
may see the formation of new yeast cells
(Fig. 8.5).
from the main plant body. Each
detached part can grow into a new
plant.
Fig. 8.4  Leaf of Bryophyllum with buds in the
margin
Boojho wants to know if
there is any advantage of
vegetative propagation.
Plants produced by vegetative
propagation take less time to grow and
bear flowers and fruits earlier than those
produced from seeds. The new plants
are exact copies of the parent plant, as
they are produced from a single parent.
Later in this chapter you will learn
that plants produced by sexual
reproduction have characters of both the
parents. Plants produce seeds as a result
of sexual reproduction.
Budding
You have already learnt about the tiny
organisms like yeast can be seen only
under a microscope. These grow and
multiply every few hours if sufficient
nutrients are made available to them.
Remember that yeast is a single-celled
organism. Let us see how they
reproduce?
The small bulb-like projection
coming out from the yeast cell is called
a bud. The bud gradually grows and
gets detached from the parent cell and
forms a new yeast cell. The new yeast
cell grows, matures and produces more
yeast cells. Sometimes, another  bud
arises from the bud forming a chain of
buds. If this process continues, a large
number of yeast cells are produced in a
short time.
Fragmentation
You might have seen slimy green
patches in ponds, or in other stagnant
water bodies. These are the algae. When
Fig. 8.5  Reproduction in yeast by budding
Yeast cell
Developing bud
Chain of buds
New bud
New plants
Reprint 2024-25
REPRODUCTION IN PLANTS 85
air. As they are very light they can cover
long distances.
Spores are asexual reproductive
bodies. Each spore is covered by a
hard protective coat to withstand
unfavourable conditions such as high
temperature and low humidity. So
they can survive for a long time. Under
favourable conditions, a spore
germinates and develops into a new
individual. Plants such as moss and
ferns (Fig. 8.8) also reproduce by means
of spores.
12.2 SEXUAL REPRODUCTION
You have learnt earlier the structure of
a flower. You know that the flowers are
the reproductive parts of a plant.
Stamens are the male reproductive part
and pistil is the female reproductive part
(Fig. 8.9).
water and nutrients are available algae
grow and multiply rapidly by
fragmentation. An alga breaks up into
two or more fragments. These fragments
or pieces grow into new individuals
(Fig. 8.6). This process continues and
they cover a large area in a short period
of time.
Fig. 8.7  Reproduction through spore formation
in fungus
Spore formation
In Chapter 1 you learnt that the fungi
on a bread piece grow from spores which
are present in the air. Repeat Activity
1.2. Observe the spores in the cotton-
like mesh on the bread. When spores
are released they keep floating in the
Fig. 8.8  Reproduction through spore formation
in fern
Hypha
Sporangium
Spores
Sori
(Spore forming
bodies)
Fig. 8.6  Fragmentation in spirogyra (an alga)
Reprint 2024-25
Page 5


Reproduction in Plants
8
T
o produce its kind is a
characteristic of all living
organisms. You have already
learnt this in Class VI. The production
of new individuals from their parents is
known as reproduction. But, how do
plants reproduce? There are different
modes of reproduction in plants which
we shall learn in this chapter.
8.1 MODES OF REPRODUCTION
In Class VI you learnt about different
parts of a flowering plant. Try to list the
various parts of a plant and write the
functions of each. Most plants have
roots, stems and leaves. These are called
the vegetative parts of a plant. After a
certain period of growth, most plants
bear flowers. You may have seen the
mango trees flowering in spring. It is
these flowers that give rise to juicy
mango fruit we enjoy in summer. We eat
the fruits and usually discard the seeds.
Seeds germinate and form new plants.
So, what is the function of flowers in
plants? Flowers perform the function of
reproduction in plants. Flowers are the
reproductive parts.
There are several ways by which
plants produce their offspring. These are
categorised into two types: (i) asexual,
and (ii) sexual reproduction. In asexual
reproduction plants can give rise to new
plants without seeds, whereas in sexual
Asexual reproduction
In asexual reproduction new plants are
obtained without production of seeds.
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, it is known as
vegetative propagation.
Activity 8.1
Cut a branch of rose or champa with a
node. This piece of branch is termed a
cutting. Bury the cutting in the soil. A
node is a part of the stem/branch at
which a leaf arises (Fig. 8.1). Water the
cutting every day and observe its
growth. Observe and record the number
of days taken for roots to come out and
Paheli thought that new
plants always grow from seeds.
But, she has never seen the seeds
of sugarcane, potato and rose. She
wants to know how these plants
reproduce.
reproduction, new plants are obtained
from seeds.
Reprint 2024-25
REPRODUCTION IN PLANTS 83
new leaves to arise. Try the same activity
by growing money plant in a jar of water
and record your observations.
Likewise you can also grow ginger
(Fig. 8.3) or turmeric.
Bryophyllum (sprout leaf plant) has
buds in the margins of leaves (Fig. 8.4).
If a leaf of this plant falls on a moist
You must have seen flower buds
developing into flowers. Apart from
flower buds, there are buds in the axil
(point of attachment of the leaf at the
node) of leaves which develop into
shoots. These buds are called vegetative
buds (Fig. 8.2). A bud consists of a short
stem around which immature
overlapping leaves are present. Vegetative
buds can also give rise to new plants.
Activity 8.2
Take a fresh potato. Observe the scars
on it with the help of a magnifying glass.
You may find bud(s) in them. These scars
are also called “eyes”. Cut the potato
into small portions, each with an eye
and bury them in the soil. Water the
pieces regularly for a few days and
observe their progress. What do you find?
Fig. 8.1  Stem-cutting of rose
Fig. 8.2  Potato plant sprouting from an ‘eye’
Fig. 8.3  Ginger with new plants sprouting
from it
soil, each bud can give rise to a new
plant.
Roots of some plants can also give
rise to new plants. Sweet potato and
dahlia are examples.
Plants such as cacti produce new
plants when their parts get detached
Node
Bud in
the axil
Reprint 2024-25
SCIENCE 84
Activity 8.3
(To be demonstrated by the teacher)
Take a piece of yeast cake or yeast
powder  from a bakery or a chemist shop.
Take a pinch of yeast and place it in a
container with some water. Add a
spoonful of sugar and shake to dissolve
it. Keep it in the warm part of a room.
After an hour, put a drop of this liquid
on a glass slide and observe under a
microscope. What do you observe? You
may see the formation of new yeast cells
(Fig. 8.5).
from the main plant body. Each
detached part can grow into a new
plant.
Fig. 8.4  Leaf of Bryophyllum with buds in the
margin
Boojho wants to know if
there is any advantage of
vegetative propagation.
Plants produced by vegetative
propagation take less time to grow and
bear flowers and fruits earlier than those
produced from seeds. The new plants
are exact copies of the parent plant, as
they are produced from a single parent.
Later in this chapter you will learn
that plants produced by sexual
reproduction have characters of both the
parents. Plants produce seeds as a result
of sexual reproduction.
Budding
You have already learnt about the tiny
organisms like yeast can be seen only
under a microscope. These grow and
multiply every few hours if sufficient
nutrients are made available to them.
Remember that yeast is a single-celled
organism. Let us see how they
reproduce?
The small bulb-like projection
coming out from the yeast cell is called
a bud. The bud gradually grows and
gets detached from the parent cell and
forms a new yeast cell. The new yeast
cell grows, matures and produces more
yeast cells. Sometimes, another  bud
arises from the bud forming a chain of
buds. If this process continues, a large
number of yeast cells are produced in a
short time.
Fragmentation
You might have seen slimy green
patches in ponds, or in other stagnant
water bodies. These are the algae. When
Fig. 8.5  Reproduction in yeast by budding
Yeast cell
Developing bud
Chain of buds
New bud
New plants
Reprint 2024-25
REPRODUCTION IN PLANTS 85
air. As they are very light they can cover
long distances.
Spores are asexual reproductive
bodies. Each spore is covered by a
hard protective coat to withstand
unfavourable conditions such as high
temperature and low humidity. So
they can survive for a long time. Under
favourable conditions, a spore
germinates and develops into a new
individual. Plants such as moss and
ferns (Fig. 8.8) also reproduce by means
of spores.
12.2 SEXUAL REPRODUCTION
You have learnt earlier the structure of
a flower. You know that the flowers are
the reproductive parts of a plant.
Stamens are the male reproductive part
and pistil is the female reproductive part
(Fig. 8.9).
water and nutrients are available algae
grow and multiply rapidly by
fragmentation. An alga breaks up into
two or more fragments. These fragments
or pieces grow into new individuals
(Fig. 8.6). This process continues and
they cover a large area in a short period
of time.
Fig. 8.7  Reproduction through spore formation
in fungus
Spore formation
In Chapter 1 you learnt that the fungi
on a bread piece grow from spores which
are present in the air. Repeat Activity
1.2. Observe the spores in the cotton-
like mesh on the bread. When spores
are released they keep floating in the
Fig. 8.8  Reproduction through spore formation
in fern
Hypha
Sporangium
Spores
Sori
(Spore forming
bodies)
Fig. 8.6  Fragmentation in spirogyra (an alga)
Reprint 2024-25
SCIENCE 86
Boojho wants to know how the
male gamete in the pollen grain
reaches the female gamete present
in the ovule.
Pollination
Generally, pollen grains have a tough
protective coat which prevents them
from drying up. Since pollen grains are
light, they can be carried by wind or
Activity 8.4
Take a mustard/China rose/petunia
flower and separate its reproductive
parts. Study the various parts of a
stamen and pistil.
Flowers which contain either only
pistil or only stamens are called
unisexual flowers. Flowers which
contain both stamens and pistil are
called bisexual flowers. Corn, papaya
and cucumber produce unisexual
flowers, whereas mustard, rose and
petunia have bisexual flowers. Both
Fig. 8.10 Pollination in flower Fig. 8.9  Reproductive parts
(b) Pistil
Stigma
Style
Ovary
Anther
Filament
(a) Stamen
Ovule
(a) Self-pollination (b)  Cross-pollination
Anther
Stigma
Stigma
male and female unisexual flowers may
be present in the same plant or in
different plants.
Could you identify the anther and
the filament of a stamen? [Fig. 8.9 (a)].
Anther contains pollen grains which
produce male gametes. A pistil consists
of stigma, style and ovary. Ovary
contains one or more ovules. The
female gamete or the egg is formed in
an ovule [Fig. 8.9 (b)]. In sexual
reproduction a male and a female
gamete fuse to form a zygote.
Pollens
Reprint 2024-25