NCERT Textbook: Getting to know Plants | Science & Technology for UPSC CSE PDF Download

 Page 1


31 GETTING TO KNOW PLANTS
4 Getting to Know Plants
G
o outside and observe all the
plants around you (Fig. 4.1).
Do you see that some plants
are small, some very big,  while some
are just patches of green on
the soil? Some have green
leaves, while some others have
reddish ones. Some have huge
red flowers, some have tiny
blue ones, while some have
none. We do see a  variety of
plants existing all around us
— near our homes, in the
school ground, on the way to
Fig. 4.2 Parts of a plant
the school, in the parks and gardens,
isn’t it?
Let us  get to know the different
parts of any plant. This will help us
understand the differences between
plants of different kinds. Can you label
the stem, branch, root, leaf, flower and
fruit of the plant shown in Fig.4.1?
Colour the parts of the plant.
4.1 HERBS, SHRUBS AND TREES
Activity 1
Look closely at the stem and branches
of:
1. Plants much smaller than you.
2. Plants that are about your size, and
3.Plants which are much taller than
you.
Feel their stem and try to bend them
gently to see if they are tender or hard.
Fig. 4.1 A Nature walk!
Flower
Shoot
system
Root
system
Fruit
Bud
Stem
Leaf
Node
Internode
Primary
root
Secondary
root
{
Rationalised 2023-24
Page 2


31 GETTING TO KNOW PLANTS
4 Getting to Know Plants
G
o outside and observe all the
plants around you (Fig. 4.1).
Do you see that some plants
are small, some very big,  while some
are just patches of green on
the soil? Some have green
leaves, while some others have
reddish ones. Some have huge
red flowers, some have tiny
blue ones, while some have
none. We do see a  variety of
plants existing all around us
— near our homes, in the
school ground, on the way to
Fig. 4.2 Parts of a plant
the school, in the parks and gardens,
isn’t it?
Let us  get to know the different
parts of any plant. This will help us
understand the differences between
plants of different kinds. Can you label
the stem, branch, root, leaf, flower and
fruit of the plant shown in Fig.4.1?
Colour the parts of the plant.
4.1 HERBS, SHRUBS AND TREES
Activity 1
Look closely at the stem and branches
of:
1. Plants much smaller than you.
2. Plants that are about your size, and
3.Plants which are much taller than
you.
Feel their stem and try to bend them
gently to see if they are tender or hard.
Fig. 4.1 A Nature walk!
Flower
Shoot
system
Root
system
Fruit
Bud
Stem
Leaf
Node
Internode
Primary
root
Secondary
root
{
Rationalised 2023-24
32 SCIENCE
Table 4.1 Categories of plants
Take care that the stem does not break.
Hug the tall plants to see how thick their
stems are!
We also need to  notice from where the
branches grow in some plants — close to
the ground or higher up on the stem.
We will now group all the plants we
observed, in Table 4.1. Some examples
are shown. You can fill the Columns 1,
2 and 3 for many more plants.
Fill Column 4 later after studying
the section.
 Based on these characters most
plants can be classified into three
categories: herbs, shrubs and trees.  An
example of each is shown in Fig.4.3.
Fig.4.3 (a) Herb, (b) shrub and (c) tree
Suggestion: Student can work in
groups of 4–5 so that a minimum
number of plants are harmed/
damaged.
You may also use weeds with soft
stems for the activities. Do you know
what weeds are? In crop fields, lawns,
or in pots, often some unwanted
plants or weeds start growing. Have
you seen farmers removing these
weeds from their fields?
(b)
(a)
(c)
Rationalised 2023-24
Page 3


31 GETTING TO KNOW PLANTS
4 Getting to Know Plants
G
o outside and observe all the
plants around you (Fig. 4.1).
Do you see that some plants
are small, some very big,  while some
are just patches of green on
the soil? Some have green
leaves, while some others have
reddish ones. Some have huge
red flowers, some have tiny
blue ones, while some have
none. We do see a  variety of
plants existing all around us
— near our homes, in the
school ground, on the way to
Fig. 4.2 Parts of a plant
the school, in the parks and gardens,
isn’t it?
Let us  get to know the different
parts of any plant. This will help us
understand the differences between
plants of different kinds. Can you label
the stem, branch, root, leaf, flower and
fruit of the plant shown in Fig.4.1?
Colour the parts of the plant.
4.1 HERBS, SHRUBS AND TREES
Activity 1
Look closely at the stem and branches
of:
1. Plants much smaller than you.
2. Plants that are about your size, and
3.Plants which are much taller than
you.
Feel their stem and try to bend them
gently to see if they are tender or hard.
Fig. 4.1 A Nature walk!
Flower
Shoot
system
Root
system
Fruit
Bud
Stem
Leaf
Node
Internode
Primary
root
Secondary
root
{
Rationalised 2023-24
32 SCIENCE
Table 4.1 Categories of plants
Take care that the stem does not break.
Hug the tall plants to see how thick their
stems are!
We also need to  notice from where the
branches grow in some plants — close to
the ground or higher up on the stem.
We will now group all the plants we
observed, in Table 4.1. Some examples
are shown. You can fill the Columns 1,
2 and 3 for many more plants.
Fill Column 4 later after studying
the section.
 Based on these characters most
plants can be classified into three
categories: herbs, shrubs and trees.  An
example of each is shown in Fig.4.3.
Fig.4.3 (a) Herb, (b) shrub and (c) tree
Suggestion: Student can work in
groups of 4–5 so that a minimum
number of plants are harmed/
damaged.
You may also use weeds with soft
stems for the activities. Do you know
what weeds are? In crop fields, lawns,
or in pots, often some unwanted
plants or weeds start growing. Have
you seen farmers removing these
weeds from their fields?
(b)
(a)
(c)
Rationalised 2023-24
33 GETTING TO KNOW PLANTS
Plants with green and tender stems
are called herbs. They are usually short
and may not have many branches
[Fig.4.3 (a)].
Some plants develop branches near
the base of stem. The stem is hard but
not very thick. Such plants are called
shrubs [Fig.4.3(b)].
Some plants are very tall and have
hard and thick stem. The stems have
branches in the upper part, much above
the ground. Such plants are called trees
[Fig.4.3(c)].
Based on the above characteristics
can you now classify the plants listed
by you and complete column 4 in
Table 4.1?
two trees, shrubs, herbs or creepers
growing in your house or school.
4.2 STEM
Observe closely the stems of different
plants around you. Note down different
Plants with weak stems that cannot
stand upright but spread on the ground
are called creepers (Fig.4.4), while those
that take support and climb up are called
climbers (Fig.4.5). These are different
from the herbs, shrubs and trees.
Perhaps there are some plants in
your school or at home that you take
care of. Write down the names of any
structures/parts borne by
the stem. Compare you
observations with the that of
your friends. What do you
find? Stems bear leaves,
branches, buds, flowers
and fruits.
Activity 2
We would require a glass, water, red/
blue ink and a soft stem. Pour water to
fill one-third of the glass. Add a few
drops of red/blue ink to the water. Cut
the base of the stem and put it in the
glass as shown in Fig.4.6.
Observe the set-up. Does the colour
appear in the stem? You will find that
the colour rises in the stem. If this is
kept for a longer period, the colour
Fig. 4.5 Climbers
Paheli wonders what kind of stem — the
money plant, beanstalk, gourd plants and
grape vines have. Do observe some of these
plants. How are these different from a herb,
a shrub or a tree? Why do you
think some of them need support
to climb upwards?
Fig. 4.4 Creepers
Rationalised 2023-24
Page 4


31 GETTING TO KNOW PLANTS
4 Getting to Know Plants
G
o outside and observe all the
plants around you (Fig. 4.1).
Do you see that some plants
are small, some very big,  while some
are just patches of green on
the soil? Some have green
leaves, while some others have
reddish ones. Some have huge
red flowers, some have tiny
blue ones, while some have
none. We do see a  variety of
plants existing all around us
— near our homes, in the
school ground, on the way to
Fig. 4.2 Parts of a plant
the school, in the parks and gardens,
isn’t it?
Let us  get to know the different
parts of any plant. This will help us
understand the differences between
plants of different kinds. Can you label
the stem, branch, root, leaf, flower and
fruit of the plant shown in Fig.4.1?
Colour the parts of the plant.
4.1 HERBS, SHRUBS AND TREES
Activity 1
Look closely at the stem and branches
of:
1. Plants much smaller than you.
2. Plants that are about your size, and
3.Plants which are much taller than
you.
Feel their stem and try to bend them
gently to see if they are tender or hard.
Fig. 4.1 A Nature walk!
Flower
Shoot
system
Root
system
Fruit
Bud
Stem
Leaf
Node
Internode
Primary
root
Secondary
root
{
Rationalised 2023-24
32 SCIENCE
Table 4.1 Categories of plants
Take care that the stem does not break.
Hug the tall plants to see how thick their
stems are!
We also need to  notice from where the
branches grow in some plants — close to
the ground or higher up on the stem.
We will now group all the plants we
observed, in Table 4.1. Some examples
are shown. You can fill the Columns 1,
2 and 3 for many more plants.
Fill Column 4 later after studying
the section.
 Based on these characters most
plants can be classified into three
categories: herbs, shrubs and trees.  An
example of each is shown in Fig.4.3.
Fig.4.3 (a) Herb, (b) shrub and (c) tree
Suggestion: Student can work in
groups of 4–5 so that a minimum
number of plants are harmed/
damaged.
You may also use weeds with soft
stems for the activities. Do you know
what weeds are? In crop fields, lawns,
or in pots, often some unwanted
plants or weeds start growing. Have
you seen farmers removing these
weeds from their fields?
(b)
(a)
(c)
Rationalised 2023-24
33 GETTING TO KNOW PLANTS
Plants with green and tender stems
are called herbs. They are usually short
and may not have many branches
[Fig.4.3 (a)].
Some plants develop branches near
the base of stem. The stem is hard but
not very thick. Such plants are called
shrubs [Fig.4.3(b)].
Some plants are very tall and have
hard and thick stem. The stems have
branches in the upper part, much above
the ground. Such plants are called trees
[Fig.4.3(c)].
Based on the above characteristics
can you now classify the plants listed
by you and complete column 4 in
Table 4.1?
two trees, shrubs, herbs or creepers
growing in your house or school.
4.2 STEM
Observe closely the stems of different
plants around you. Note down different
Plants with weak stems that cannot
stand upright but spread on the ground
are called creepers (Fig.4.4), while those
that take support and climb up are called
climbers (Fig.4.5). These are different
from the herbs, shrubs and trees.
Perhaps there are some plants in
your school or at home that you take
care of. Write down the names of any
structures/parts borne by
the stem. Compare you
observations with the that of
your friends. What do you
find? Stems bear leaves,
branches, buds, flowers
and fruits.
Activity 2
We would require a glass, water, red/
blue ink and a soft stem. Pour water to
fill one-third of the glass. Add a few
drops of red/blue ink to the water. Cut
the base of the stem and put it in the
glass as shown in Fig.4.6.
Observe the set-up. Does the colour
appear in the stem? You will find that
the colour rises in the stem. If this is
kept for a longer period, the colour
Fig. 4.5 Climbers
Paheli wonders what kind of stem — the
money plant, beanstalk, gourd plants and
grape vines have. Do observe some of these
plants. How are these different from a herb,
a shrub or a tree? Why do you
think some of them need support
to climb upwards?
Fig. 4.4 Creepers
Rationalised 2023-24
34 SCIENCE
Let us get to know the leaf better by
taking its impression! If you thought
that leaves cannot sign, here is an
activity which will make you think again.
Activity 3
Put a leaf under a white sheet of paper
or a sheet in your notebook. Hold it in
place as shown in Fig. 4.9. Hold your
pencil tip sideways and rub it on the
portion of the paper having the leaf below
it. Did you get an impression with some
lines in it? Are they similar to those on
the leaf?
These lines on
the leaf are called
veins. Do you see
a prominent line
in the middle of the
leaf? This is called
the midrib. The
design made by
veins in a leaf is
called the leaf venation. If this design is
net-like on both sides of midrib, the
venation is reticulate [Fig. 4.10 (a)]. In
the leaves of grass you might have seen
that the veins are parallel to one another.
This is parallel venation [(Fig. 4.10 (b)].
Observe the venation in as many leaves
as you can without removing them from
the plant. Draw the pattern and write
Fig. 4.9 Taking an
impression of a leaf
4.3 LEAF
Observe the leaves of some plants
around you and draw them in your
notebook. Are all the leaves of same size,
shape and colour?
How are leaves attached to the stem?
The part of leaf by which it is attached
to the stem is called petiole. The broad,
green part of the leaf is called lamina
(Fig. 4.8). Can you identify these parts
of the leaves in plants around you? Do
all the leaves have petioles?
Fig. 4.7 (a) Water moves up the stem and
      reaches leaves
(b) Enlarged view of open end of stem
(a)
(b)
Fig. 4.6 Stem in a glass with coloured water
appears in the veins of leaves also. How
do you think the colour reached there?
From this activity, we see that the
stem helps in upward movement of
water. The water and minerals go to
leaves and other plant parts attached to
the stem.
Fig. 4.8 A leaf
Lamina
Petiole
Stem
Rationalised 2023-24
Page 5


31 GETTING TO KNOW PLANTS
4 Getting to Know Plants
G
o outside and observe all the
plants around you (Fig. 4.1).
Do you see that some plants
are small, some very big,  while some
are just patches of green on
the soil? Some have green
leaves, while some others have
reddish ones. Some have huge
red flowers, some have tiny
blue ones, while some have
none. We do see a  variety of
plants existing all around us
— near our homes, in the
school ground, on the way to
Fig. 4.2 Parts of a plant
the school, in the parks and gardens,
isn’t it?
Let us  get to know the different
parts of any plant. This will help us
understand the differences between
plants of different kinds. Can you label
the stem, branch, root, leaf, flower and
fruit of the plant shown in Fig.4.1?
Colour the parts of the plant.
4.1 HERBS, SHRUBS AND TREES
Activity 1
Look closely at the stem and branches
of:
1. Plants much smaller than you.
2. Plants that are about your size, and
3.Plants which are much taller than
you.
Feel their stem and try to bend them
gently to see if they are tender or hard.
Fig. 4.1 A Nature walk!
Flower
Shoot
system
Root
system
Fruit
Bud
Stem
Leaf
Node
Internode
Primary
root
Secondary
root
{
Rationalised 2023-24
32 SCIENCE
Table 4.1 Categories of plants
Take care that the stem does not break.
Hug the tall plants to see how thick their
stems are!
We also need to  notice from where the
branches grow in some plants — close to
the ground or higher up on the stem.
We will now group all the plants we
observed, in Table 4.1. Some examples
are shown. You can fill the Columns 1,
2 and 3 for many more plants.
Fill Column 4 later after studying
the section.
 Based on these characters most
plants can be classified into three
categories: herbs, shrubs and trees.  An
example of each is shown in Fig.4.3.
Fig.4.3 (a) Herb, (b) shrub and (c) tree
Suggestion: Student can work in
groups of 4–5 so that a minimum
number of plants are harmed/
damaged.
You may also use weeds with soft
stems for the activities. Do you know
what weeds are? In crop fields, lawns,
or in pots, often some unwanted
plants or weeds start growing. Have
you seen farmers removing these
weeds from their fields?
(b)
(a)
(c)
Rationalised 2023-24
33 GETTING TO KNOW PLANTS
Plants with green and tender stems
are called herbs. They are usually short
and may not have many branches
[Fig.4.3 (a)].
Some plants develop branches near
the base of stem. The stem is hard but
not very thick. Such plants are called
shrubs [Fig.4.3(b)].
Some plants are very tall and have
hard and thick stem. The stems have
branches in the upper part, much above
the ground. Such plants are called trees
[Fig.4.3(c)].
Based on the above characteristics
can you now classify the plants listed
by you and complete column 4 in
Table 4.1?
two trees, shrubs, herbs or creepers
growing in your house or school.
4.2 STEM
Observe closely the stems of different
plants around you. Note down different
Plants with weak stems that cannot
stand upright but spread on the ground
are called creepers (Fig.4.4), while those
that take support and climb up are called
climbers (Fig.4.5). These are different
from the herbs, shrubs and trees.
Perhaps there are some plants in
your school or at home that you take
care of. Write down the names of any
structures/parts borne by
the stem. Compare you
observations with the that of
your friends. What do you
find? Stems bear leaves,
branches, buds, flowers
and fruits.
Activity 2
We would require a glass, water, red/
blue ink and a soft stem. Pour water to
fill one-third of the glass. Add a few
drops of red/blue ink to the water. Cut
the base of the stem and put it in the
glass as shown in Fig.4.6.
Observe the set-up. Does the colour
appear in the stem? You will find that
the colour rises in the stem. If this is
kept for a longer period, the colour
Fig. 4.5 Climbers
Paheli wonders what kind of stem — the
money plant, beanstalk, gourd plants and
grape vines have. Do observe some of these
plants. How are these different from a herb,
a shrub or a tree? Why do you
think some of them need support
to climb upwards?
Fig. 4.4 Creepers
Rationalised 2023-24
34 SCIENCE
Let us get to know the leaf better by
taking its impression! If you thought
that leaves cannot sign, here is an
activity which will make you think again.
Activity 3
Put a leaf under a white sheet of paper
or a sheet in your notebook. Hold it in
place as shown in Fig. 4.9. Hold your
pencil tip sideways and rub it on the
portion of the paper having the leaf below
it. Did you get an impression with some
lines in it? Are they similar to those on
the leaf?
These lines on
the leaf are called
veins. Do you see
a prominent line
in the middle of the
leaf? This is called
the midrib. The
design made by
veins in a leaf is
called the leaf venation. If this design is
net-like on both sides of midrib, the
venation is reticulate [Fig. 4.10 (a)]. In
the leaves of grass you might have seen
that the veins are parallel to one another.
This is parallel venation [(Fig. 4.10 (b)].
Observe the venation in as many leaves
as you can without removing them from
the plant. Draw the pattern and write
Fig. 4.9 Taking an
impression of a leaf
4.3 LEAF
Observe the leaves of some plants
around you and draw them in your
notebook. Are all the leaves of same size,
shape and colour?
How are leaves attached to the stem?
The part of leaf by which it is attached
to the stem is called petiole. The broad,
green part of the leaf is called lamina
(Fig. 4.8). Can you identify these parts
of the leaves in plants around you? Do
all the leaves have petioles?
Fig. 4.7 (a) Water moves up the stem and
      reaches leaves
(b) Enlarged view of open end of stem
(a)
(b)
Fig. 4.6 Stem in a glass with coloured water
appears in the veins of leaves also. How
do you think the colour reached there?
From this activity, we see that the
stem helps in upward movement of
water. The water and minerals go to
leaves and other plant parts attached to
the stem.
Fig. 4.8 A leaf
Lamina
Petiole
Stem
Rationalised 2023-24
35 GETTING TO KNOW PLANTS
names of some plants having reticulate
and parallel venation.
Shall we now find out some of the
functions of a leaf?
Activity 4
We will require a herb, two transparent
polythene bags and thread.
Do this activity during day time on a
sunny day. Use a healthy, well watered
plant that has been growing in the sun.
Enclose a leafy branch of the  plant in a
polythene cover and tie up its mouth as
shown in Fig. 4.11. Tie up the mouth of
another empty polythene cover and keep
it also in the sun.
After a few hours, observe the inner
surface of the covers. What do you see?
Are there any droplets of water? How do
you think they got there? [Don’t forget
to remove the polythene bag after the
activity!]
Water comes out of leaves in the form
of vapour by a process called
transpiration. Plants release a lot of water
into the air through this process.
Why did we tie a cover around the
leaves? Would we have seen the water
evaporate if we had not tied a polythene
Fig. 4.10 Leaf venation (a) reticulate and
(b) parallel
(a) (b)
Fig. 4.11 What does the leaf do?
Midrib Veins Transparent
polythene
cover/bag
Fig. 4.12 What does the leaf contain?
Green
leaf Iodine
solution
Blue
Black
coloured
leaf
cover? What makes the water appear on
the polythene bag? In Chapter 5, we
noticed water changing into different
forms in some of our activities. Can you
think of these and name the process that
makes water drops appear on the
polythene cover?
Leaves also have another function.
Let us study this.
Activity 5
We would require a leaf, spirit, a beaker,
test tube, burner, water, a watch glass
and iodine solution for this activity.
Take a leaf in a test tube and pour
spirit to completely immerse the leaf.
Rationalised 2023-24