Class 7 Science Chapter 10 NCERT Book - Life Processes in Plants

 Page 1


Life Processes 
in Plants
10
In Grade 6, we learnt that all living beings grow and need food 
for their growth. Also, in the previous chapter, we discussed the 
process through which animals obtain nutrition.  
We know that animals eat food to grow, but what about 
plants? Have you ever seen plants eating food like animals do? 
As animals grow, their size and weight usually increase, and their 
bodies undergo various changes. What changes do you notice in 
plants when they grow?
We learnt that food provides nutrients like carbohydrates, 
fats, proteins, vitamins, and minerals, which, along with water, 
are all essential for growth. Let us explore how plants obtain 
nutrients for their growth.
Chapter 10.indd   137 4/3/2025   4:55:45 PM
Page 2


Life Processes 
in Plants
10
In Grade 6, we learnt that all living beings grow and need food 
for their growth. Also, in the previous chapter, we discussed the 
process through which animals obtain nutrition.  
We know that animals eat food to grow, but what about 
plants? Have you ever seen plants eating food like animals do? 
As animals grow, their size and weight usually increase, and their 
bodies undergo various changes. What changes do you notice in 
plants when they grow?
We learnt that food provides nutrients like carbohydrates, 
fats, proteins, vitamins, and minerals, which, along with water, 
are all essential for growth. Let us explore how plants obtain 
nutrients for their growth.
Chapter 10.indd   137 4/3/2025   4:55:45 PM
Curiosity | Textbook of Science | Grade 7
138
10.1 How Do Plants Grow?
Look around your neighbourhood. Have you observed any 
changes in a plant during its life span? As a plant grows, new 
leaves and branches emerge, its height increases, and its stem 
thickens. What do you think causes these changes? Discuss with 
your friends and provide your explanation as well. 
When we water plants 
regularly, they grow better. 
So, I think water also 
contributes to its growth.
I think sunlight plays 
some role in the growth 
of  plants.
Maybe plants take 
up food from the soil 
through their roots. 
I think, maybe, ________ 
plays some role!
Let us perform an experiment to test some of these explanations. 
Activity 10.1: Let us test some explanations 
? Take three earthen pots (or used bottles/containers) of the 
same size ? lled with garden soil. Plant saplings of similar sizes 
of a fast-growing plant like chilli or 
tomato in each pot (Fig. 10.1).
? Label the pots A, B, and C.
? Count the number of leaves on 
each sapling and record your 
observations.
? Place pot A in direct sunlight. Keep 
the soil in this pot slightly moist 
by adding an adequate amount of 
water every day (Fig. 10.1a).
? Place pot B in direct sunlight, 
without adding water to the soil 
(Fig. 10.1b). 
A B
C
(a) Pot A kept in 
direct sunlight, 
with water
(b) Pot B kept in 
direct sunlight, 
without water 
Fig. 10.1: Experimental set-up to understand 
the role of sunlight and water in plant growth
(c) Pot C kept in 
the dark, with 
water
Chapter 10.indd   138 4/3/2025   4:55:47 PM
Page 3


Life Processes 
in Plants
10
In Grade 6, we learnt that all living beings grow and need food 
for their growth. Also, in the previous chapter, we discussed the 
process through which animals obtain nutrition.  
We know that animals eat food to grow, but what about 
plants? Have you ever seen plants eating food like animals do? 
As animals grow, their size and weight usually increase, and their 
bodies undergo various changes. What changes do you notice in 
plants when they grow?
We learnt that food provides nutrients like carbohydrates, 
fats, proteins, vitamins, and minerals, which, along with water, 
are all essential for growth. Let us explore how plants obtain 
nutrients for their growth.
Chapter 10.indd   137 4/3/2025   4:55:45 PM
Curiosity | Textbook of Science | Grade 7
138
10.1 How Do Plants Grow?
Look around your neighbourhood. Have you observed any 
changes in a plant during its life span? As a plant grows, new 
leaves and branches emerge, its height increases, and its stem 
thickens. What do you think causes these changes? Discuss with 
your friends and provide your explanation as well. 
When we water plants 
regularly, they grow better. 
So, I think water also 
contributes to its growth.
I think sunlight plays 
some role in the growth 
of  plants.
Maybe plants take 
up food from the soil 
through their roots. 
I think, maybe, ________ 
plays some role!
Let us perform an experiment to test some of these explanations. 
Activity 10.1: Let us test some explanations 
? Take three earthen pots (or used bottles/containers) of the 
same size ? lled with garden soil. Plant saplings of similar sizes 
of a fast-growing plant like chilli or 
tomato in each pot (Fig. 10.1).
? Label the pots A, B, and C.
? Count the number of leaves on 
each sapling and record your 
observations.
? Place pot A in direct sunlight. Keep 
the soil in this pot slightly moist 
by adding an adequate amount of 
water every day (Fig. 10.1a).
? Place pot B in direct sunlight, 
without adding water to the soil 
(Fig. 10.1b). 
A B
C
(a) Pot A kept in 
direct sunlight, 
with water
(b) Pot B kept in 
direct sunlight, 
without water 
Fig. 10.1: Experimental set-up to understand 
the role of sunlight and water in plant growth
(c) Pot C kept in 
the dark, with 
water
Chapter 10.indd   138 4/3/2025   4:55:47 PM
Life Processes in Plants
139
? Place pot C in the dark. Keep the soil in this pot slightly moist 
by adding an adequate amount of water every day (Fig. 10.1c).
? Observe the plants for two weeks
1
 and record changes in 
their height, number of leaves, colour of leaves, and any 
other changes that may appear.
? Record your observations in Table 10.1.
Table 10.1: E? ect of sunlight and water on plant growth
Availability of 
Pot A: In direct 
sunlight, with 
water
Pot B: In direct 
sunlight, 
without water
Pot C: In the 
dark, with 
water
Height of plant 
(cm)
Sunlight
Day 1 Day 1
Water
After 2 
weeks
After 2 
weeks
Number of 
leaves
Colour of 
leaves 
(Green/Yellow)
Pots kept 
under 
di? erent 
conditions
? What di? erences did you observe between the plants in the 
three pots? 
? Which pot has the plant with the maximum growth?
? Which pot has the plant with the least growth?
Analyse the observations recorded in Table 10.1, and discuss 
them with your teacher and friends.
You are likely to ? nd that the plant in Pot A, kept in direct 
sunlight with adequate water, grows better than the plant in Pot 
C, which gets adequate water but no sunlight. The plant in Pot 
B may have died as it did not get water even though it received 
adequate sunlight.
What do you infer from the observations made in this activity? 
The results indicate that plants require both sunlight and water 
for their growth. 
1   This experiment will need two weeks. Teachers can plan this activity 
accordingly.
Chapter 10.indd   139 4/3/2025   4:55:47 PM
Page 4


Life Processes 
in Plants
10
In Grade 6, we learnt that all living beings grow and need food 
for their growth. Also, in the previous chapter, we discussed the 
process through which animals obtain nutrition.  
We know that animals eat food to grow, but what about 
plants? Have you ever seen plants eating food like animals do? 
As animals grow, their size and weight usually increase, and their 
bodies undergo various changes. What changes do you notice in 
plants when they grow?
We learnt that food provides nutrients like carbohydrates, 
fats, proteins, vitamins, and minerals, which, along with water, 
are all essential for growth. Let us explore how plants obtain 
nutrients for their growth.
Chapter 10.indd   137 4/3/2025   4:55:45 PM
Curiosity | Textbook of Science | Grade 7
138
10.1 How Do Plants Grow?
Look around your neighbourhood. Have you observed any 
changes in a plant during its life span? As a plant grows, new 
leaves and branches emerge, its height increases, and its stem 
thickens. What do you think causes these changes? Discuss with 
your friends and provide your explanation as well. 
When we water plants 
regularly, they grow better. 
So, I think water also 
contributes to its growth.
I think sunlight plays 
some role in the growth 
of  plants.
Maybe plants take 
up food from the soil 
through their roots. 
I think, maybe, ________ 
plays some role!
Let us perform an experiment to test some of these explanations. 
Activity 10.1: Let us test some explanations 
? Take three earthen pots (or used bottles/containers) of the 
same size ? lled with garden soil. Plant saplings of similar sizes 
of a fast-growing plant like chilli or 
tomato in each pot (Fig. 10.1).
? Label the pots A, B, and C.
? Count the number of leaves on 
each sapling and record your 
observations.
? Place pot A in direct sunlight. Keep 
the soil in this pot slightly moist 
by adding an adequate amount of 
water every day (Fig. 10.1a).
? Place pot B in direct sunlight, 
without adding water to the soil 
(Fig. 10.1b). 
A B
C
(a) Pot A kept in 
direct sunlight, 
with water
(b) Pot B kept in 
direct sunlight, 
without water 
Fig. 10.1: Experimental set-up to understand 
the role of sunlight and water in plant growth
(c) Pot C kept in 
the dark, with 
water
Chapter 10.indd   138 4/3/2025   4:55:47 PM
Life Processes in Plants
139
? Place pot C in the dark. Keep the soil in this pot slightly moist 
by adding an adequate amount of water every day (Fig. 10.1c).
? Observe the plants for two weeks
1
 and record changes in 
their height, number of leaves, colour of leaves, and any 
other changes that may appear.
? Record your observations in Table 10.1.
Table 10.1: E? ect of sunlight and water on plant growth
Availability of 
Pot A: In direct 
sunlight, with 
water
Pot B: In direct 
sunlight, 
without water
Pot C: In the 
dark, with 
water
Height of plant 
(cm)
Sunlight
Day 1 Day 1
Water
After 2 
weeks
After 2 
weeks
Number of 
leaves
Colour of 
leaves 
(Green/Yellow)
Pots kept 
under 
di? erent 
conditions
? What di? erences did you observe between the plants in the 
three pots? 
? Which pot has the plant with the maximum growth?
? Which pot has the plant with the least growth?
Analyse the observations recorded in Table 10.1, and discuss 
them with your teacher and friends.
You are likely to ? nd that the plant in Pot A, kept in direct 
sunlight with adequate water, grows better than the plant in Pot 
C, which gets adequate water but no sunlight. The plant in Pot 
B may have died as it did not get water even though it received 
adequate sunlight.
What do you infer from the observations made in this activity? 
The results indicate that plants require both sunlight and water 
for their growth. 
1   This experiment will need two weeks. Teachers can plan this activity 
accordingly.
Chapter 10.indd   139 4/3/2025   4:55:47 PM
Curiosity | Textbook of Science | Grade 7
140
FASCINATING FACTS
???
? ?
???
???
? ???? ?????? ???? ? ? ????? ? ??: ?
“Trees do not produce fruits and flowers merely because they are planted.”
This line is from an ancient Indian text named Vrikshayurveda. It records 
useful observations about plant growth, soil, and agricultural practices to 
help improve crop health, growth and production. The knowledge in the 
text seems to be based on practical experiences and patterns seen over 
time. These ideas were then systematically documented to guide farming 
practices. For instance, there are references to di? erent methods of organic 
manure preparation, such as mixing water, barley, and various seeds, like 
green, black, and horse grams.
. It records 
useful observations about plant growth, soil, and agricultural practices to 
help improve crop health, growth and production. The knowledge in the 
text seems to be based on practical experiences and patterns seen over 
time. These ideas were then systematically documented to guide farming 
practices. For instance, there are references to di? erent methods of organic 
manure preparation, such as mixing water, barley, and various seeds, like 
10.2  How Do Plants Get Food for their 
Growth?
We know that animals get their food from plants, either directly by 
eating plants or indirectly by eating animals that in turn eat plants 
for their nutrition and growth. But how do plants obtain the food 
they need to grow? Unlike animals, plants do not eat food. 
10.2.1 Leaves: the ??food factories? of plants
Plants store food in the form of starch, a type of carbohydrate. 
This starch is produced in the leaves of a plant which, by design, 
are generally broad and ? at. These are mostly green because of 
the presence of a green pigment called chlorophyll, that helps in 
capturing sunlight e?  ciently.
Let us ? nd out the role chlorophyll plays in the preparation of 
food in the form of starch in plants.  food in the form of starch in plants.  
Activity 10.2: Let us check (demonstration activity)
The teacher may demonstrate this 
activity.
? Keep a leaf in boiling water  for 
? ve minutes to soften it.
? Dip this leaf in a test tube 
containing alcohol.
? Place the test tube in a beaker 
containing boiling water. 
Wait until the leaf becomes 
colourless (Fig. 10.2a). 
(a) Boiling set-up (b) Iodine test
Fig. 10.2: Starch test in a leaf
Water
Alcohol
Leaf
Sprit lamp
Wire
gauze
Test 
tube
Iodine 
solution
Chapter 10.indd   140 4/3/2025   4:55:48 PM
Page 5


Life Processes 
in Plants
10
In Grade 6, we learnt that all living beings grow and need food 
for their growth. Also, in the previous chapter, we discussed the 
process through which animals obtain nutrition.  
We know that animals eat food to grow, but what about 
plants? Have you ever seen plants eating food like animals do? 
As animals grow, their size and weight usually increase, and their 
bodies undergo various changes. What changes do you notice in 
plants when they grow?
We learnt that food provides nutrients like carbohydrates, 
fats, proteins, vitamins, and minerals, which, along with water, 
are all essential for growth. Let us explore how plants obtain 
nutrients for their growth.
Chapter 10.indd   137 4/3/2025   4:55:45 PM
Curiosity | Textbook of Science | Grade 7
138
10.1 How Do Plants Grow?
Look around your neighbourhood. Have you observed any 
changes in a plant during its life span? As a plant grows, new 
leaves and branches emerge, its height increases, and its stem 
thickens. What do you think causes these changes? Discuss with 
your friends and provide your explanation as well. 
When we water plants 
regularly, they grow better. 
So, I think water also 
contributes to its growth.
I think sunlight plays 
some role in the growth 
of  plants.
Maybe plants take 
up food from the soil 
through their roots. 
I think, maybe, ________ 
plays some role!
Let us perform an experiment to test some of these explanations. 
Activity 10.1: Let us test some explanations 
? Take three earthen pots (or used bottles/containers) of the 
same size ? lled with garden soil. Plant saplings of similar sizes 
of a fast-growing plant like chilli or 
tomato in each pot (Fig. 10.1).
? Label the pots A, B, and C.
? Count the number of leaves on 
each sapling and record your 
observations.
? Place pot A in direct sunlight. Keep 
the soil in this pot slightly moist 
by adding an adequate amount of 
water every day (Fig. 10.1a).
? Place pot B in direct sunlight, 
without adding water to the soil 
(Fig. 10.1b). 
A B
C
(a) Pot A kept in 
direct sunlight, 
with water
(b) Pot B kept in 
direct sunlight, 
without water 
Fig. 10.1: Experimental set-up to understand 
the role of sunlight and water in plant growth
(c) Pot C kept in 
the dark, with 
water
Chapter 10.indd   138 4/3/2025   4:55:47 PM
Life Processes in Plants
139
? Place pot C in the dark. Keep the soil in this pot slightly moist 
by adding an adequate amount of water every day (Fig. 10.1c).
? Observe the plants for two weeks
1
 and record changes in 
their height, number of leaves, colour of leaves, and any 
other changes that may appear.
? Record your observations in Table 10.1.
Table 10.1: E? ect of sunlight and water on plant growth
Availability of 
Pot A: In direct 
sunlight, with 
water
Pot B: In direct 
sunlight, 
without water
Pot C: In the 
dark, with 
water
Height of plant 
(cm)
Sunlight
Day 1 Day 1
Water
After 2 
weeks
After 2 
weeks
Number of 
leaves
Colour of 
leaves 
(Green/Yellow)
Pots kept 
under 
di? erent 
conditions
? What di? erences did you observe between the plants in the 
three pots? 
? Which pot has the plant with the maximum growth?
? Which pot has the plant with the least growth?
Analyse the observations recorded in Table 10.1, and discuss 
them with your teacher and friends.
You are likely to ? nd that the plant in Pot A, kept in direct 
sunlight with adequate water, grows better than the plant in Pot 
C, which gets adequate water but no sunlight. The plant in Pot 
B may have died as it did not get water even though it received 
adequate sunlight.
What do you infer from the observations made in this activity? 
The results indicate that plants require both sunlight and water 
for their growth. 
1   This experiment will need two weeks. Teachers can plan this activity 
accordingly.
Chapter 10.indd   139 4/3/2025   4:55:47 PM
Curiosity | Textbook of Science | Grade 7
140
FASCINATING FACTS
???
? ?
???
???
? ???? ?????? ???? ? ? ????? ? ??: ?
“Trees do not produce fruits and flowers merely because they are planted.”
This line is from an ancient Indian text named Vrikshayurveda. It records 
useful observations about plant growth, soil, and agricultural practices to 
help improve crop health, growth and production. The knowledge in the 
text seems to be based on practical experiences and patterns seen over 
time. These ideas were then systematically documented to guide farming 
practices. For instance, there are references to di? erent methods of organic 
manure preparation, such as mixing water, barley, and various seeds, like 
green, black, and horse grams.
. It records 
useful observations about plant growth, soil, and agricultural practices to 
help improve crop health, growth and production. The knowledge in the 
text seems to be based on practical experiences and patterns seen over 
time. These ideas were then systematically documented to guide farming 
practices. For instance, there are references to di? erent methods of organic 
manure preparation, such as mixing water, barley, and various seeds, like 
10.2  How Do Plants Get Food for their 
Growth?
We know that animals get their food from plants, either directly by 
eating plants or indirectly by eating animals that in turn eat plants 
for their nutrition and growth. But how do plants obtain the food 
they need to grow? Unlike animals, plants do not eat food. 
10.2.1 Leaves: the ??food factories? of plants
Plants store food in the form of starch, a type of carbohydrate. 
This starch is produced in the leaves of a plant which, by design, 
are generally broad and ? at. These are mostly green because of 
the presence of a green pigment called chlorophyll, that helps in 
capturing sunlight e?  ciently.
Let us ? nd out the role chlorophyll plays in the preparation of 
food in the form of starch in plants.  food in the form of starch in plants.  
Activity 10.2: Let us check (demonstration activity)
The teacher may demonstrate this 
activity.
? Keep a leaf in boiling water  for 
? ve minutes to soften it.
? Dip this leaf in a test tube 
containing alcohol.
? Place the test tube in a beaker 
containing boiling water. 
Wait until the leaf becomes 
colourless (Fig. 10.2a). 
(a) Boiling set-up (b) Iodine test
Fig. 10.2: Starch test in a leaf
Water
Alcohol
Leaf
Sprit lamp
Wire
gauze
Test 
tube
Iodine 
solution
Chapter 10.indd   140 4/3/2025   4:55:48 PM
Life Processes in Plants
141
? Take out the leaf and place it on a plate. 
? Now, put a few drops of diluted iodine solution with the help 
of a dropper on the decolourised leaf (Fig. 10.2b). Wait for a 
few minutes and observe.
? If the colour of the leaf changes to blue-black, it indicates the 
presence of starch.
Caution?— Alcohol should never be placed near a heat source directly, 
as it is highly ? ammable and can easily lead to ? re and burns. 
Did you wonder why we decolourise the leaf in the 
beginning of this activity?
Decolourisation of a leaf enables us to easily observe 
colour change and, thus, the presence of starch.
D
IVE
EEPER D
IVE
EEPER
In Activity 10.1, we have learnt that water and sunlight are 
essential for plant growth. In Activity 10.2, we have discovered 
that green leaves store starch as food. 
Bhaskar loves gardening during his free time. Being a curious 
student, he often looks around his garden and wonders how 
plants produce food. From his experiences, Bhaskar knows 
that water and sunlight are essential for plant growth. But he 
wonders if sunlight contributes to the production of food in the 
form of starch in plants.
How does sunlight 
contribute in the production 
of starch in plants? 
Activity 10.3: Let us check 
Bhaskar took a leaf having both green and non-green patches 
from each of two similar potted plants — one kept in sunlight and 
the other kept in the dark for 36 hours. He wanted to compare 
the leaves before and after the starch test. 
He made a sketch of the leaves to record the location of the 
green and the non-green patches on them with the help of a 
tracing paper. After that, he performed an iodine test (as shown 
in Activity 10.2) on the leaves. Bhaskar recorded his observations 
in Table 10.2. 
Chapter 10.indd   141 4/3/2025   4:55:49 PM