NCERT Solutions for Class 7 Science Curiosity Chapter 9 Life Processes in Animals

NCERT Solutions for Class 7 Science Curiosity Chapter 9  Life Processes in Animals help students understand how animals, including humans, carry out important functions like eating, breathing, transporting nutrients, and removing waste. The chapter explains these life processes nutrition, respiration, circulation, and excretion in a simple way using examples, activities, and diagrams. NCERT Solutions for Class 7 Science Curiosity Chapter 9 make it easier for students to learn and revise the concepts and are useful for scoring well in school exams.

NCERT Solutions for Class 7 Science Curiosity Chapter 9 Introduction

Chapter 9 of Class 7 Science Curiosity, titled "Life Processes in Animals," focuses on the essential functions that animals perform to stay alive. These life processes include nutrition, respiration, circulation, and excretion. The chapter begins with an explanation of how animals obtain and digest food through the alimentary canal, with the help of saliva, digestive juices, and enzymes.

It then explains the process of respiration, showing how oxygen is taken in and used to release energy from food. Students also learn about the circulatory system, including the heart, blood vessels, and how blood carries oxygen and nutrients to different parts of the body. Finally, the chapter covers excretion, describing how waste materials are removed from the body, especially through the kidneys.

With the help of simple language, diagrams, experiments, and classroom activities, this chapter builds a strong understanding of how the animal body functions. It lays the foundation for learning more about the human body and other organisms in higher classes.

Class 7 Science Chapter 9 Life Processes in Animals Question Answer

Below are the solutions for Class 7 Science Chapter 9  Life Processes in Animals. These question answers are prepared as per the latest Class 7 Science syllabus guidelines and are meant to help students understand key concepts such as nutrition, respiration, circulation, and excretion in animals. 

Activity 9.1: Let us investigate 

 Take two test tubes and label them as ‘A’ and ‘B’.  

Take one teaspoonful of boiled rice in test tube A, and take a teaspoonful of boiled rice after chewing it for 30–60 seconds in test tube B.  Add 3–4 mL of water in both the test tubes.  

Note the initial colour of the rice-water mixture in Table 9.1.  

Add 3–4 drops of iodine solution into each test tube with the help of a dropper. Mix the content of each test tube separately and observe. Record your observations in Table 9.1.

Answer:

Aim:
To observe the action of saliva (present in the mouth) on starch present in food.

Steps:

1. Take two test tubes – label them A and B.

2. Put one teaspoon of boiled rice in test tube A.

3. Chew one teaspoon of boiled rice for about 30–60 seconds and then put it in test tube B.

4. Add 3–4 mL of water in both test tubes and mix well.

5. Observe and note the initial color of both mixtures.

6. Add 3–4 drops of iodine solution in both test tubes using a dropper.

7. Mix well and observe any color change.

Table 9.1: Action of Saliva on Starch

Conclusion:

This activity shows that saliva helps digest starch. When we chew food, the saliva starts breaking down starch into sugar. That’s why the color doesn't change much when iodine is added to chewed rice.

Answer:

Aim:
To create a model that shows how the lungs work during breathing.

Materials Needed:

• A transparent plastic bottle with a lid

• A Y-shaped hollow tube (like a straw splitter)

• Two balloons

• A rubber sheet (or a piece of balloon or glove)

• Rubber bands

• Some clay or glue to seal

Procedure:

1. Take a transparent plastic bottle and cut off its bottom part.

2. Make a hole in the bottle cap.

3. Attach two balloons to the forked ends of the Y-shaped tube and seal them with rubber bands so no air escapes.

4. Insert the straight end of the Y-tube through the cap and seal it with clay to make it airtight.

5. Close the bottle with the lid and ensure the Y-tube with balloons hangs inside the bottle.

6. Cover the open bottom of the bottle with a thin rubber sheet (like a balloon piece) and fix it with a rubber band.

How It Works (Observation & Explanation):

Conclusion:

This model shows how our lungs work during breathing. The rubber sheet at the bottom acts like the diaphragm. When it moves, it changes the air pressure inside the bottle (chest cavity), causing air to move in or out of the balloons (lungs).

Activity 9.3: Let us explore

 To be demonstrated by the teacher  Take an equal amount of freshly prepared lime water in two test tubes, A and B, as given in Fig. 9.11. 

 In test tube A, pass the air using a syringe/pichkari (Fig. 9.11a). This is the same air that you inhale. 

 In test tube B, repeatedly blow air through your mouth into the lime water using a straw (Fig. 9.11b).  Do you observe any changes in the colour of the lime water? 

Answer:

Aim:
To compare the amount of carbon dioxide in inhaled and exhaled air using lime water.

Materials Needed:

• Two test tubes labeled A and B

• Freshly prepared lime water (a solution of calcium hydroxide)

• A syringe or pichkari (for test tube A)

• A straw (for test tube B)

Procedure:

1. Fill both test tubes A and B with equal amounts of fresh lime water.

2. In test tube A, pass air using a syringe or pichkari. This air represents the inhaled air.

3. In test tube B, blow air from your mouth into the lime water using a straw. This represents the exhaled air.

4. Observe the changes in color in both test tubes.

Observation:

Conclusion:

This activity shows that exhaled air contains more carbon dioxide than inhaled air.
When carbon dioxide is blown into lime water, it reacts to form calcium carbonate, which makes the solution milky. Since the air we exhale has more carbon dioxide, test tube B turns milky, while test tube A stays clear.

In-Text Questions (Page 127–128)

Q1. Cows keep chewing the food even when they are not actively grazing or eating anything. Why? (Page 127)

Answer:
Cows keep chewing because they are chewing the food they had already swallowed earlier. This is called rumination or chewing the cud. It helps them digest tough plant food properly and get more nutrients from it.

Q2. Is the process of respiration the same in all animals? (Page 128)

 Answer:
No, respiration is not the same in all animals. It differs based on the animal’s size, body structure, and where it lives. Some animals use lungs, others use gills or even skin to breathe and carry out respiration.

Let Us Enhance Our Learning 

Question 1:Complete the journey of food through the alimentary canal by filling up the boxes with appropriate parts.

Answer: Journey of Food through the Alimentary Canal

The path followed by food in the human digestive system is as follows:

1. Mouth – Food enters the body and is chewed and mixed with saliva

2. Food pipe (Oesophagus) – Pushes food down into the stomach.

3. Stomach – Food is mixed with digestive juices and partly digested.

4. Small intestine – Most digestion and absorption of nutrients happen here.

5. Large intestine – Absorbs water from the leftover material.

6. Anus – The undigested waste is removed from the body.

Question 2: Sahil placed some pices of chapati in test tube A. Neha placed chewed chapati in test tube B, and Santushti took boiled and mashed potato in test tube C. All of them added a few drops of iodine solution to their test tubes A, B, and C, respectively. What would be their observations? Give reasons.
Answer:
Their observations are explained in the table below:

Question 3. What is the role of diaphragm in breathing?
(i) To filter the air
(ii) To produce sound
(iii) To help in inhalation and exhalation
(iv) To absorb oxygen
Answer:
(iii) To help in inhalation and exhalation

Question 4. Match the following:

Answer:

 Question 5: Anil claims to his friend Sanvi that respiration and breathing are the same process. What question(s) can Sanvi ask him to make him understand that he is not correct?

Answer:
Sanvi can ask Anil questions like:

• Do plants breathe like humans? How do they take in oxygen?

• When we breathe out, the carbon dioxide we release—does it come from breathing or respiration?

• Is it possible for the body to continue respiration for a short time even if we hold our breath?

• Can you think of any example where breathing happens but energy is not released like in respiration?

These questions will help Anil realize that breathing is just the physical process of taking in air and releasing it, while respiration is a chemical process that happens inside our body to produce energy.

Question 6: Which of the following statements is correct and why?

• Anu: We inhale air.

• Shanu: We inhale oxygen.

• Tanu: We inhale air rich in oxygen.

Answer:
Tanu is correct.
When we breathe in, we don’t take in pure oxygen. We inhale air, which contains about 21% oxygen, along with other gases like nitrogen and carbon dioxide. That’s why it is right to say we inhale air rich in oxygen, not just oxygen alone.

Question 7: We often sneeze when we inhale a lot of dust-laden air. What can be possible explanations for this? 

Answer:
When we breathe in air full of dust, the tiny dust particles get stuck in the tiny hairs and mucus inside our nose. These particles irritate the inner lining of our nose. To get rid of them, our body reacts by making us sneeze, which helps throw out the dust and lets only clean air go into our lungs.

Question 8: Paridhi and Anusha of Grade 7 started running for their morning workout. After they completed their running, they counted their breaths per minute. Anusha was breathing faster than Paridhi. Provide at least two possible explanations for why Anusha was breathing faster than Paridhi. 

Answer:
There could be two reasons:

1. Anusha might not be as fit or healthy as Paridhi, so her body needs more oxygen while running.

2. She could be having breathing issues like a cold or asthma, which makes it harder for her to get enough oxygen, so she breathes faster to make up for it.

Question 9. Yadu conducted an experiment to test his idea. He took two test tubes, A and B, and added a pinch of rich flour to the test tubes half-filled with water and stirred them properly. To test tube B, he added a few drops of saliva. He left the two test tubes for 35-45 min. After that, he added iodine solution into both the test tubes. Experimental results are as shown in Fig. 9.15. What do you think he wants to test?

Fig. Experimental results

Answer:

Yadu wants to test the presence of starch in both test tubes

Answer:
Rakshita was trying to find out what kind of gases are present in the air we breathe in and the air we breathe out.

She noticed that the lime water in test tube B (with exhaled air) turned milky, while the lime water in test tube A (with inhaled air) stayed clear.

This shows that exhaled air has more carbon dioxide, because lime water turns milky when it reacts with carbon dioxide. So, her experiment confirms that the air we breathe out contains more carbon dioxide than the air we breathe in.

NCERT Solutions for Class 7 Science Curiosity Chapter 9 PDF Download

 Students can download the NCERT Solutions for Class 7 Science Curiosity Chapter 9  Life Processes in Animals in PDF format from the link given below. These solutions are prepared as per the latest syllabus and help students understand key concepts like digestion, respiration, circulation, and excretion in animals. The PDF is easy to read and can be used for quick revision before exams.

Benefits of Using NCERT Solutions for Class 7 Science Curiosity Chapter 9

Here are the benefits of using NCERT Solutions for Class 7 Science Curiosity Chapter 9:

• Helps students clearly understand important life processes like digestion, respiration, circulation, and excretion.

• Solutions are based on the latest NCERT curriculum, making them accurate and exam-relevant.

• Answers are written in simple language, making it easier for students to grasp key concepts.

• Includes explanations of textbook activities to connect theory with real-life understanding.

• Useful for quick revision before class tests and exams.

• Promotes self-study by providing step-by-step and easy-to-follow answers.