---
title: "NCERT Solutions Class 7 Science Ch 10 Life Processes in Plants"
url: https://www.swavid.com/science/class/7/chapter/life-processes-in-plants/ncert-solutions
dateModified: 2026-10-07T16:10:23+00:00
---

# NCERT Solutions Class 7 Science Ch 10 Life Processes in Plants

This chapter's questions cover the understanding of life processes in plants such as growth requirements, photosynthesis, respiration, and transport systems.

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## In-text questions

### Question 1

*3 marks · Short answer*

What changes do you notice in plants when they grow?

**Solution**

1. As a plant grows, new leaves and branches emerge.
2. The height of the plant increases over time.
3. The stem of the plant thickens as it grows.

**Answer:** New leaves and branches emerge, height increases, and the stem thickens.

> Common mistake: Only mentioning height increase while ignoring stem thickening and emergence of new leaves.

### Question 2

*3 marks · Short answer*

What do you think causes these changes? Discuss with your friends and provide your explanation as well.

**Solution**

1. Plants require essential resources like water from the soil taken up by roots.
2. Sunlight plays a crucial role in providing energy for the growth of plants.
3. Plants also obtain nutrients and air from their surroundings for proper development.

**Answer:** Changes in plants are caused by the availability of water, sunlight, and nutrients from the soil.

> Common mistake: Forgetting that plants need both water and sunlight simultaneously.

### Question 3

*3 marks · Short answer*

What differences did you observe between the plants in the three pots?

**Solution**

1. Pot A (direct sunlight, with water) shows healthy growth with an increase in height and number of leaves.
2. Pot B (direct sunlight, without water) shows poor growth or the plant may die due to lack of water.
3. Pot C (in the dark, with water) shows weak growth with pale or yellow leaves because of the absence of sunlight.

**Answer:** Pot A grows well, Pot B dies without water, and Pot C grows poorly without sunlight.

> Common mistake: Confusing the condition of Pot B with Pot C.

### Question 4

*3 marks · Short answer*

Which pot has the plant with the maximum growth?

**Solution**

1. Pot A is kept in direct sunlight and provided with adequate water every day.
2. Both sunlight and water are essential for proper plant growth.
3. Therefore, the plant in Pot A exhibits maximum growth.

**Answer:** Pot A has the plant with the maximum growth.

> Common mistake: Naming Pot B or Pot C instead of Pot A.

### Question 5

*3 marks · Short answer*

Which pot has the plant with the least growth?

**Solution**

1. Pot B is kept in direct sunlight but is not given any water.
2. Plants cannot survive or grow without water, causing the plant in Pot B to die or show the least growth.
3. Pot C also shows poor growth due to lack of sunlight, but Pot B suffers completely without water.

**Answer:** Pot B has the plant with the least growth or may have died.

> Common mistake: Choosing Pot C as the one with least growth while ignoring that Pot B received no water at all.

### Question 6

*3 marks · Short answer*

What do you infer from the observations made in this activity?

**Solution**

1. The plant in Pot A grows better than the plant in Pot C which lacks sunlight.
2. The plant in Pot B dies because it does not get water despite receiving sunlight.
3. This indicates that plants require both sunlight and water for their growth.

**Answer:** Plants require both sunlight and water for their growth.

> Common mistake: Concluding that only water or only sunlight is enough for plant growth.

### Question 7

*3 marks · Short answer*

Did you wonder why we decolourise the leaf in the beginning of this activity?

**Solution**

1. We decolourise the leaf in the beginning of the starch test activity by boiling it in alcohol.
2. This removes the green-coloured chlorophyll pigment from the leaf.
3. Decolourisation enables us to easily observe the colour change with iodine and thus the presence of starch.

**Answer:** Decolourising the leaf removes chlorophyll so that the colour change indicating the presence of starch can be easily observed.

> Common mistake: Thinking alcohol dissolves starch instead of chlorophyll.

### Question 8

*3 marks · Short answer*

How does sunlight contribute in the production of starch in plants?

**Solution**

1. Sunlight provides the light energy required by green plants to manufacture food.
2. It enables chlorophyll present in the leaves to synthesise starch from carbon dioxide and water.
3. In the absence of sunlight, green leaves cannot produce starch.

**Answer:** Sunlight provides energy for chlorophyll to produce starch during photosynthesis.

> Common mistake: Confusing sunlight as a raw material rather than a source of energy.

### Question 9

*3 marks · Short answer*

What do we infer from the observations listed in Table 10.2?

**Solution**

1. Table 10.2 shows that starch is produced only where green patches containing chlorophyll are present.
2. It also shows that starch is not produced in leaves kept in the dark.
3. We infer that chlorophyll and sunlight are both essential for the preparation of starch in plants.

**Answer:** Chlorophyll and sunlight are essential for the production of starch in leaves.

> Common mistake: Ignoring the role of light conditions recorded in the table.

### Question 10

*3 marks · Short answer*

What else is essential for the preparation of food in plants?

**Solution**

1. Plants require carbon dioxide gas from the air for the preparation of food.
2. Water taken up by the roots from the soil is also essential.
3. Sunlight and chlorophyll complete the list of necessary requirements for photosynthesis.

**Answer:** Carbon dioxide from the air is essential along with water, sunlight, and chlorophyll for preparing food in plants.

> Common mistake: Forgetting carbon dioxide or water while listing essentials.

### Question 11

*3 marks · Short answer*

Which gas from the air is essential in the process of food preparation in plants?

**Solution**

1. Carbon dioxide is the gas from the air that is essential in the process of food preparation in plants.
2. Plants take in carbon dioxide through tiny pores called stomata on their leaves.
3. It is utilised along with water and sunlight during photosynthesis to produce glucose.

**Answer:** Carbon dioxide is the essential gas from the air used in food preparation.

> Common mistake: Writing oxygen instead of carbon dioxide as the raw material.

### Question 12

*3 marks · Short answer*

What does this experiment show?

**Solution**

1. The experiment shows the role of carbon dioxide in the preparation of starch by plants.
2. The part of the leaf inside the bottle does not turn blue-black because caustic soda absorbs carbon dioxide.
3. This proves that carbon dioxide present in the air is essential for plants to prepare starch.

**Answer:** The experiment shows that carbon dioxide present in the air is essential for plants to prepare starch.

> Common mistake: Confusing the function of caustic soda with the role of sunlight.

### Question 13

*3 marks · Short answer*

Based on Activities 10.3 and 10.4, what do you conclude? Which part of the plant is involved in the synthesis of starch?

**Solution**

1. Sunlight, water, chlorophyll, and carbon dioxide are essential for the synthesis of starch in plants.
2. This process of food preparation in the presence of sunlight and chlorophyll is called photosynthesis.
3. The leaf is the primary part involved in the synthesis of starch.

**Answer:** Sunlight, water, chlorophyll, and carbon dioxide are essential for photosynthesis, and the leaf is the primary part involved in the synthesis of starch.

> Common mistake: Forgetting to mention all four essential factors required for photosynthesis.

### Question 14

*3 marks · Short answer*

Do other green parts of the plant also perform photosynthesis?

**Solution**

1. Photosynthesis requires chlorophyll to capture sunlight for preparing food.
2. Only green parts of plants contain the green pigment chlorophyll.
3. Yes, other green parts of the plants which have chlorophyll also perform photosynthesis.

**Answer:** Yes, other parts of the plants that have chlorophyll also perform photosynthesis.

> Common mistake: Thinking that only leaves perform photosynthesis in a plant.

### Question 15

*3 marks · Short answer*

Do plants only take in substances from their surroundings, or do they also release something?

**Solution**

1. Plants take in carbon dioxide from the air and water from the soil for photosynthesis.
2. During the process of photosynthesis, plants also release substances into their surroundings.
3. Oxygen is released during photosynthesis as a product.

**Answer:** Plants do not just take in substances from their surroundings, but they also release oxygen during photosynthesis.

> Common mistake: Stating that plants only take in carbon dioxide and water without mentioning what they release.

### Question 16

*3 marks · Short answer*

What difference do you observe in the two set-ups? Do you observe air bubbles emerging in the inverted test tube in set-up A? The gas produced in this set-up caused bubbles to emerge and get accumulated in the inverted test tube. Which gas is this?

**Solution**

1. Set-up A is placed in sunlight and shows air bubbles emerging, whereas set-up B in the dark does not show this.
2. Yes, we observe air bubbles emerging in the inverted test tube in set-up A.
3. The gas produced and accumulated in the test tube is oxygen.

**Answer:** Set-up A shows air bubbles emerging while set-up B does not; the gas collected in the inverted test tube is oxygen.

> Common mistake: Confusing oxygen with carbon dioxide as the gas produced during photosynthesis in sunlight.

### Question 17

*3 marks · Short answer*

Which part of the plant helps in the exchange of carbon dioxide and oxygen?

**Solution**

1. Plants require carbon dioxide for photosynthesis and release oxygen.
2. The exchange of carbon dioxide and oxygen takes place through leaves.
3. Tiny pores present on the surface of leaves, called stomata, help in the exchange of gases.

**Answer:** Stomata present on the surface of leaves help in the exchange of carbon dioxide and oxygen.

> Common mistake: Not mentioning stomata as the specific structures responsible for gas exchange.

### Question 18

*3 marks · Short answer*

What do you observe? Do you notice tiny pores on the peel, as shown in Fig. 10.6?

**Solution**

1. When a leaf peel is observed under a microscope, tiny pores are visible.
2. Yes, we notice tiny pores on the peel as shown in Fig. 10.6.
3. These tiny pores are called stomata, which help in the exchange of gases.

**Answer:** Yes, we observe tiny pores called stomata on the leaf peel under a microscope.

> Common mistake: Failing to identify the tiny pores as stomata.

### Question 19

*3 marks · Short answer*

How do water and minerals taken up by the roots move to all parts of the plant?

**Solution**

1. Water and minerals are taken up from the soil by the roots of a plant.
2. They move upwards through a thin tube-like structure called the xylem present in the stem, branches, and leaves.
3. Through the xylem, water and minerals are transported to all parts of the plant.

**Answer:** Water and minerals move to all parts of the plant through the xylem.

> Common mistake: Forgetting to mention the xylem tissue.

### Question 20

*3 marks · Short answer*

What do you notice? Compare the plant stems placed in the tumblers. Do you observe red colour in the stem, leaves, and flowers of the plant from Tumbler B?

**Solution**

1. On comparing the plant stems placed in the two tumblers, we observe a distinct red colour in the stem, leaves, and flowers of the plant placed in Tumbler B (containing water with red ink).
2. The plant in Tumbler A (with plain water) shows no such red colour.
3. This indicates that the coloured water has moved upwards through the plant.

**Answer:** Yes, red colour is observed in the stem, leaves, and flowers of the plant from Tumbler B.

> Common mistake: Confusing Tumbler A and Tumbler B observations.

### Question 21

*3 marks · Short answer*

How did different parts of the plant acquire this red colour?

**Solution**

1. The plant was placed in water mixed with red ink.
2. The roots and stem absorbed this coloured water.
3. The red-coloured water travelled upwards through the internal transport tubes to reach the stem, leaves, and flowers.

**Answer:** The different parts acquired the red colour by absorbing the red-coloured water from Tumbler B which travelled upwards.

> Common mistake: Not mentioning the absorption and upward movement of water.

### Question 22

*3 marks · Short answer*

Do you spot the red colour in the stem (Fig. 10.7e)? How does the red colour ink move upwards?

**Solution**

1. Yes, the red colour is clearly spotted inside the stem when observed with a magnifying glass.
2. The red-coloured ink moves upwards through a thin tube-like structure called the xylem.
3. Xylem is present in the stem, branches, and leaves, and helps in transporting water and dissolved minerals upwards.

**Answer:** Red colour is spotted in the stem, and the ink moves upwards through the xylem.

> Common mistake: Omitting the name of the conducting tissue, xylem.

### Question 23

*3 marks · Short answer*

How does food get transported to other parts of a plant?

**Solution**

1. Food is prepared by the leaves during photosynthesis.
2. This prepared food is transported from the leaves to all other parts of the plant.
3. The transport of food takes place through another set of thin tube-like structures called the phloem.

**Answer:** Food is transported to other parts of the plant through the phloem.

> Common mistake: Confusing xylem with phloem for food transport.

### Question 24

*3 marks · Short answer*

Do plants also respire like we do?

**Solution**

1. Yes, plants also respire like other living beings.
2. During respiration, plants break down glucose in the presence of oxygen to release carbon dioxide, water, and energy.
3. All parts of a plant, green or non-green, carry out respiration to obtain energy for growth and development.

**Answer:** Yes, plants respire by breaking down glucose using oxygen to release energy, carbon dioxide, and water.

> Common mistake: Thinking plants only perform photosynthesis and not respiration.

### Question 25

*3 marks · Short answer*

Compare both the test tubes for any change in colour. Does the lime water turn milky in both the test tubes? Why does the lime water turn milky in the test tube connected to the flask?

**Solution**

1. Lime water does not turn milky in both test tubes; it turns milky only in the test tube connected to the conical flask containing germinating seeds.
2. The lime water turns milky because the germinating seeds respire, taking in oxygen and releasing carbon dioxide into the flask.
3. This excess carbon dioxide passes through the tube into the lime water and turns it milky.

**Answer:** Lime water turns milky only in the test tube connected to the flask because germinating seeds release carbon dioxide during respiration.

> Common mistake: Thinking that lime water turns milky in both test tubes due to atmospheric air.

## Let Us Enhance Our Learning

### Question 1

*3 marks · Short answer*

Complete the following table comparing Photosynthesis and Respiration for features: 1. Raw materials, 2. Products, 3. Word equation, 4. Importance.

**Solution**

1. 1. For raw materials: Photosynthesis uses carbon dioxide and water, whereas respiration uses glucose and oxygen.
2. 2. For products: Photosynthesis produces glucose and oxygen, whereas respiration produces carbon dioxide, water, and energy.
3. 3. For word equation and importance: Photosynthesis converts light energy into chemical energy to synthesize food, while respiration breaks down glucose to release energy for life processes.

**Answer:** Photosynthesis and respiration differ in their raw materials, products, equations, and biological importance as summarized in the table.

> Common mistake: Confusing the raw materials of photosynthesis with those of respiration.

### Question 2

*3 marks · Short answer*

Imagine a situation where all the organisms that carry out photosynthesis on the earth have disappeared. What would be the impact of this on living organisms?

**Solution**

1. 1. Photosynthesis is the primary process by which plants synthesize food and release oxygen into the atmosphere.
2. 2. Without photosynthetic organisms, herbivores and carnivores would not get food, leading to the starvation and extinction of animal life.
3. 3. Furthermore, living organisms would run out of oxygen required for respiration, making life on Earth impossible.

**Answer:** Without photosynthesis, there would be no food or oxygen on Earth, resulting in the extinction of all living organisms.

> Common mistake: Forgetting to mention the lack of oxygen along with the lack of food.

### Question 3

*3 marks · Short answer*

A potato slice shows the presence of starch with iodine solution. Where does the starch in potatoes come from? Where is the food synthesised in the plant, and how does it reach the potato?

**Solution**

1. 1. The starch in potatoes comes from glucose produced during photosynthesis in the leaves.
2. 2. Food is synthesized in the leaves, which are the primary site of photosynthesis.
3. 3. The synthesized food is transported from the leaves to the underground potato tuber through thin tube-like structures called phloem.

**Answer:** Starch in potatoes is synthesized in the leaves via photosynthesis and transported to the potato through the phloem.

> Common mistake: Stating that food is transported through xylem instead of phloem.

### Question 4

*3 marks · Short answer*

Does the broad and flat structure of leaves make plants more efficient for photosynthesis? Justify your answer.

**Solution**

1. 1. Yes, the broad and flat structure of leaves makes plants more efficient for photosynthesis.
2. 2. A broad and flat surface provides a large area to capture maximum sunlight efficiently.
3. 3. It also exposes more stomata to the air for the exchange of carbon dioxide and oxygen.

**Answer:** The broad and flat structure provides a larger surface area to capture sunlight and absorb carbon dioxide efficiently.

> Common mistake: Not linking the broad structure to maximum absorption of sunlight and gases.

### Question 5

*3 marks · Short answer*

X is broken down using Y to release carbon dioxide, Z, and energy. 
X + Y -> Carbon dioxide + Z + Energy 
X, Y, and Z are three different components of the process. What do X, Y, and Z stand for?

**Solution**

1. State the word equation for respiration given in the textbook: $\text{Glucose} + \text{Oxygen} \rightarrow \text{Carbon dioxide} + \text{Water} + \text{Energy}$.
2. Compare the given equation with the standard respiration equation: $X + Y \rightarrow \text{Carbon dioxide} + Z + \text{Energy}$.
3. Identify the components: $X$ stands for glucose, $Y$ stands for oxygen, and $Z$ stands for water.

**Answer:** X stands for glucose, Y stands for oxygen, and Z stands for water.

> Common mistake: Confusing photosynthesis and respiration equations.

### Question 6

*3 marks · Case-based*

Krishna set-up an experiment with two potted plants of same size and placed one of them in sunlight and the other in a dark room, as shown in Fig. 10.10. Answer the following questions —
(i) What idea might she be testing through this experiment?
(ii) What are the visible differences in plants in both the conditions?
(iii) According to you, leaves of which plants confirm the iodine test for the presence of starch?

**Part (i)**

1. 1. Krishna might be testing whether sunlight is essential for the production of food (starch) in plants.

Answer (i): She is testing the role of sunlight in plant food production.

**Part (ii)**

1. 1. The plant kept in sunlight remains healthy and green, whereas the plant kept in the dark may appear pale or weak due to lack of food synthesis.

Answer (ii): The plant in sunlight is healthy, while the plant in the dark shows reduced vitality and pale leaves.

**Part (iii)**

1. 1. Leaves of the plant kept in sunlight confirm the iodine test by turning blue-black, indicating the presence of starch.

Answer (iii): Leaves of the plant kept in sunlight.

**Answer:** Krishna's experiment tests the necessity of sunlight for starch formation in plants.

> Common mistake: Confusing the plant kept in the dark with the one in sunlight for starch production.

### Question 7

*3 marks · Short answer*

Vani believes that 'carbon dioxide is essential for photosynthesis'. She puts an experimental set-up, as shown in Fig. 10.11, to collect evidence to support or reject her idea.
(a) Sunlight with carbon dioxide
(b) Sunlight without carbon dioxide
(c) Dark with carbon dioxide
(d) Dark without carbon dioxide
Answer the following questions —
(i) In which plant(s) in the above set-up(s) will starch be formed?
(ii) In which plant(s) in the above set-up(s) will starch not be formed?
(iii) In which plant(s) in the above set-up(s) will oxygen be generated?
(iv) In which plant(s) in the above set-up(s) will oxygen not be generated?

**Part (i)**

1. Starch is produced only when both sunlight and carbon dioxide are available.
2. Therefore, starch will be formed in plant (a).

Answer (i): Plant (a)

**Part (ii)**

1. Starch is not produced in the absence of sunlight or carbon dioxide.
2. Therefore, starch will not be formed in plants (b), (c), and (d).

Answer (ii): Plants (b), (c), and (d)

**Part (iii)**

1. Oxygen is released during photosynthesis, which takes place in the presence of sunlight and carbon dioxide.
2. Therefore, oxygen will be generated in plant (a).

Answer (iii): Plant (a)

**Part (iv)**

1. Oxygen is not generated when photosynthesis does not occur due to lack of sunlight or carbon dioxide.
2. Therefore, oxygen will not be generated in plants (b), (c), and (d).

Answer (iv): Plants (b), (c), and (d)

**Answer:** Starch and oxygen are formed only in the plant kept in sunlight with carbon dioxide (set-up a).

> Common mistake: Confusing the conditions required for photosynthesis with those required for respiration.

### Question 8

*3 marks · Short answer*

Ananya took four test tubes and filled three-fourth of each test tube with water. She labelled them A, B, C, and D (Fig. 10.12). In test tube A, she kept a snail; in test tube B, she kept a water plant; in test tube C, she kept both a snail and a plant. In test tube D, she kept only water. Ananya added a carbon dioxide indicator to all the test tubes. She recorded the initial colour of water and observed if there are any colour changes in the test tubes after 2–3 hours. What do you think she wants to find out? How will she know if she is correct?

**Solution**

1. Ananya wants to find out how respiration by animals and photosynthesis by water plants affect the amount of carbon dioxide in water.
2. Snails release carbon dioxide through respiration, which turns the indicator acidic, while water plants consume carbon dioxide during photosynthesis.
3. She will know if she is correct by observing the colour changes of the carbon dioxide indicator in the different test tubes after 2 to 3 hours.

**Answer:** Ananya wants to study the exchange of carbon dioxide between aquatic animals and plants using a carbon dioxide indicator.

> Common mistake: Forgetting that both plants and animals respire, while only plants perform photosynthesis in the light.

### Question 9

*3 marks · Short answer*

Design an experiment to observe if water transportation in plants is quicker in warm or cold conditions.

**Solution**

1. Take two similar tender plant twigs with white flowers and two glass tumblers labelled A and B containing water mixed with red ink.
2. Place tumbler A in a warm place (like in sunlight) and tumbler B in a cool place (like in a shaded or air-conditioned room).
3. Observe the time taken for the red colour to appear in the stems and flowers of both plants, and conclude that water transportation is quicker in warm conditions.

**Answer:** An experiment using red-coloured water to compare the rate of water transport in warm and cool environments.

> Common mistake: Not keeping other variables like plant size and amount of red ink constant.

### Question 10

*3 marks · Short answer*

Photosynthesis and respiration are essential to maintain balance in nature. Discuss.

**Solution**

1. During photosynthesis, plants take in carbon dioxide and release oxygen into the atmosphere.
2. During respiration, all living organisms consume oxygen and release carbon dioxide back into the atmosphere.
3. These two complementary processes cycle gases continuously, maintaining a balance of oxygen and carbon dioxide in nature.

**Answer:** Photosynthesis and respiration complement each other to maintain the balance of oxygen and carbon dioxide in nature.

> Common mistake: Stating that plants only perform photosynthesis and not respiration.

## Frequently asked questions

### How many questions are there in NCERT Solutions for Class 7 Science Chapter 10 Life Processes in Plants?

This chapter has a total of 35 questions based on the new NCERT book for the 2026-27 session. This includes 25 in-text questions and 10 questions in the Let Us Enhance Our Learning section. SwaVid provides complete step-by-step solutions for all these questions on this page only.

### What topics do the questions in this chapter cover?

The in-text questions cover concepts like the decolourisation of leaf, essential gas for photosynthesis, exchange of gases, and water transportation using red ink. The exercise questions further explore plant respiration, food synthesis, the structure of leaves, and the balance of oxygen and carbon dioxide in nature. SwaVid helps you master all these topics with clear explanations.

### Which are the hardest question types in this chapter and how should I approach them?

Case-based and experimental analysis questions are generally considered the toughest in this chapter. To approach them, carefully study the given observations from experiments like water transportation under different temperature conditions or data like Table 10.2. SwaVid's expert solutions on this page break down these complex scenarios into simple logical steps.

### How can I write answers for full marks in Class 7 Science Chapter 10 examinations?

To secure full marks, structure your answers by clearly stating scientific terms, mentioning key experimental observations, and explaining biological processes step by step. Drawing neat diagrams for concepts like stomata or water movement also helps impress examiners. You can refer to SwaVid's solved examples available on this page to learn the correct answer-writing format.

### Is a free PDF available for Class 7 Science Chapter 10 Life Processes in Plants?

Yes, a free PDF containing comprehensive step-by-step solutions for this chapter is available right here on this page. You can easily download or view the content online to prepare thoroughly according to the latest NCF 2023 syllabus for the 2026-27 session. SwaVid ensures all solutions are accurate and easy to understand.

## Related pages

- [Class 7 Science chapters](https://www.swavid.com/science/class/7)

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