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

The class 7 science chapter 9 question answer guide for "Life Processes in Animals" helps you understand how living beings stay alive. From how we get energy from food to how we breathe, this chapter covers the big jobs our bodies do. Learning these answers is a big part of doing well in your Science tests.

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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.

Read More: NCERT Solutions for Class 7 Science Chapter 1

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.

Read More: NCERT Solutions for Class 7 Science Chapter 2

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.

Read More: NCERT Solutions for Class 7 Science Chapter 6

Learn Class 7 Science Chapter 9 Question Answer

Getting ready for your school test is easy when you look at the main ideas. In this chapter, you will learn how food moves through your body and how your lungs help you get air. You will also see how different animals, like fish and frogs, have special ways to breathe. If you practice these class 7 science chapter 9 question answer steps, you will find it easy to explain how life works.

The Path of Your Food (Digestion)

Digestion is how the body breaks food into tiny bits it can use. You should know the path food takes for your class 7 science chapter 9 question answer work.

• The Mouth: Eating starts here. Your teeth mash food, and spit (saliva) breaks down starch.

• The Spit Test: In class, you might see that rice turns blue with a special liquid called iodine. But if you chew the rice first, it does not change color. This is because your spit already turned the starch into sugar.

• The Stomach: Here, food mixes with a strong liquid called acid. This acid kills germs and helps break down meat and beans (proteins).

• The Small Tummy (Intestine): This is where the body takes in the good stuff from food. It gets help from the liver and the pancreas to finish the job.

• Tiny Fingers: The inside of the small tummy has tiny parts like fingers called villi. They help the blood soak up all the energy from your food.

Taking in Air and Making Energy

Many students think breathing and making energy are the same, but they are different. This is a common cbse class 7 science chapter 9 question answer topic.

1. Breathing: This is just moving air. We breathe in good air (oxygen). A big muscle under your lungs called the diaphragm moves down to pull air in and up to push it out.

2. Making Energy (Respiration): This happens deep inside your body. Your body uses the oxygen to "burn" the food you ate to give you power to run and play.

3. The Proof: If you blow air through a straw into "lime water," the water turns milky white. This proves that the air you breathe out is full of carbon dioxide (waste air).

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How Other Animals Live

Not all animals are like us. Some have very cool body parts. This is a big part of the class 7 science chapter 9 question answer pdf.

• Cows: They swallow grass fast and bring it back to their mouth to chew again later. This is called chewing the cud.

• Birds: Birds have no teeth! Instead, they have a part called a gizzard. It uses small stones they swallow to grind up their food like a blender.

• Bugs: Many bugs breathe through tiny holes and tubes on their sides called spiracles and tracheae.

• Frogs: They are amazing because they can breathe through their lungs on land and through their wet skin in water.

• Fish: Fish use gills to take air out of the water.

Science and You

You can think about your own body to understand these steps better. This is often in class 7 science chapter 9 question answer in english tests.

• Sneezing: This happens when dust gets in your nose. Your body blows it out fast to keep your lungs clean.

• Running: When you run fast, you breathe fast. Your body needs more power, so it asks for more air to make energy.

• The Long Tube: Your food tube is like one long, wiggly pipe. It moves food along by squeezing it, almost like moving a marble through a rubber hose.

Friendly Advice for Your Science Test

When you write your answers, use short points. Teachers like neat work. Drawing a small picture, like a tooth or a heart, can help you get better marks.

Writing Good Answers

Always start by telling what a word means. For example, if you are asked about villi, say they are "tiny fingers in the tummy." This shows the teacher you know your stuff.

Using Your Time Well

Don't spend too long on one question. Practice writing your answers at home so you can finish the test fast. Students who use a class 7 science chapter 9 question answer list to practice usually do a better job. Try using a timer to see how fast you can write. This helps you stay calm so you have time to check your drawings at the end. Writing in clear dots (bullets) makes your paper easy to read.

To boost your marks, always draw neat diagrams with clear labels. Focus on big topics like the human heart or the respiratory system. Practice these sketches until you can draw them in under two minutes. Using a sharp pencil and a ruler for labeling lines makes your work look like a pro's!

Check Out: Junoon For Class 7 Combo Set of 5 Books

Class 7 Science Chapter 9 FAQs

1. Where does the body start breaking down food?
   It starts in the mouth as soon as you chew and mix food with spit.

2. What is the diaphragm?
   It is a muscle that helps your lungs breathe air in and out.

3. Why do birds swallow small stones?
   They use the stones in their gizzard to mash up their food since they don't have teeth.

4. Why does lime water turn white when we blow into it?
   Because the waste air (carbon dioxide) from our body changes the water.

5. How do earthworms breathe?
   They breathe through their wet, slimy skin!