NCERT Solutions Class 7 Science Chapter 9 Life Processes in Animals

The study of life processes lies at the heart of understanding how living organisms sustain themselves. In Class 7 Science – Chapter 9: Life Processes in Animals, the NCERT Solutions delves into the essential functions that enable animals to grow, reproduce, and interact with their environment. You'll explore how animals eat, breathe, transport materials, and eliminate waste—mechanisms crucial for survival.

This NCERT Solutions Class 7 Science chapter builds upon foundational concepts learned in earlier grades, linking the intricate systems within animal bodies to everyday phenomena—like digestion, breathing, and blood circulation. Through detailed explanations, illustrative diagrams, and hands-on activities, learners gain clarity on how nature’s machinery operates inside us.

1.0NCERT Solutions Class 7 Science Chapter 9 Life Processes in Animals - Download PDF

Access the NCERT Solutions for Class 7 Science Chapter 9 PDF – Life Processes in Animals, which includes step-by-step answers to all in-text and exercise questions drawn directly from the updated Curiosity. 

2.0Key Concepts in Chapter 9: Life Processes in Animals

A deep dive into the chapter reveals four major topics:

1. Nutrition in Animals 

Animals obtain food in varied ways—herbivores grazing, carnivores hunting, omnivores eating both plants and animals, and filter feeders like sponges and whales . The nutrition section traces the journey of food:

• Ingestion: Food enters through the mouth
• Digestion: Mechanical (chewing) and chemical (saliva) breakdown
• Alimentary canal: Organs include oesophagus, stomach, small & large intestines, anus Absorption: Nutrients move into blood via the small intestine
• Egestion: Unusable waste expelled from the body

Special cases, like ruminants chewing cud (e.g., cows) and the enzymatic tests using iodine and saliva, are explained with practical examples .

2. Respiration

NCERT describes respiration as the process of breaking down food with oxygen for energy. This includes:

• External respiration – intake of oxygen and exhalation of carbon dioxide using lungs (or gills in aquatic animals) 
• Cellular respiration – breakdown of glucose inside cells releasing energy, water, and CO₂ .

The diaphragm's role in breathing, and the differences in respiration across animal groups, are also covered.

3. Transportation

Though primarily focused on nutrition and respiration, the chapter briefly mentions how animals like humans transport food, oxygen, and wastes via blood and lymph systems. The heart pumps blood throughout the body’s channels, feeding every cell.

4. Excretion

Animals must eliminate metabolic wastes—like CO₂, water, salts, and urea—to maintain balance. This section explains:

• Removal of CO₂ via lungs, water and salts via sweat and kidneys
• The role of kidneys and skin in excretory functions

Though less extensively detailed in this chapter, excretion is framed as one of the essential life processes.

3.0NCERT Class 7 Science Chapter 9 Life Process in Animals: Detailed Solutions

• Complete the journey of food through the alimentary canal by filling up the boxes with appropriate parts. Ans. The completed journey of food through the alimentary canal with the appropriate parts filled in - Food $\to$ Mouth $\to$ Oesophagus $\to$ Stomach $\to$ Small Intestine $\to$ Large Intestine $\to$ Anus
• Sahil placed some pieces 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 $\mathrm{A},\mathrm{B}$ and C , respectively. What would be their observations? Give reasons. Ans. Test Tube A: (Sahil: Pieces of chapati) Observation: The chapati pieces will turn blue-black when iodine is added. Reason: Chapati is rich in starch and iodine reacts with starch to form a blue-black complex. Since the chapati is unchewed, the starch is still present in its original form. Test Tube B: (Neha: Chewed chapati) Observation: The colour change may be less intense or no blue-black colour may appear. Reason: Saliva contains an enzyme called salivary amylase (ptyalin) that begins breaking down starch into sugar (maltose). Since the starch has been partially digested, there's less starch to react with iodine, resulting in a weaker or no colour change. Test Tube C: (Santushti: Boiled and mashed potato) Observation: The potato will turn blueblack upon adding iodine. Reason: Potatoes contain a lot of starch and boiling doesn't break it down into sugar. Iodine reacts with this starch to give the blue-black colour.
• What is the role of the diaphragm in breathing? (i) To filter the air (ii) To produce sound (iii) To help in inhalation and exhalation (iv) To absorb oxygen Ans: The correct answer is (iii) (a) To help in inhalation and exhalation (b) During inhalation, the diaphragm contracts and moves downward, increasing the space in the chest cavity and allowing the lungs to expand and fill with air. (c) During exhalation, the diaphragm relaxes and moves upward, reducing the space in the chest cavity and pushing air out of the lungs.
• Match the following

Ans.

• 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? Ans. I. Does breathing give us energy? II Where does the oxygen go after we breathe it in? III. Why do we need food to get energy? IV. Do our body cells breathe like we do? V. Why do we call it 'cellular respiration' and not 'cellular breathing? These questions will help anil to understand that breathing is the physical process of inhaling and exhaling. While respiration is the chemical process where oxygen is used to break down glucose to release energy.
• Which of the following statements is correct and why? Anu: We inhale air. Shanu: We inhale oxygen. Tanu: We inhale air rich in oxygen. Ans: Tanu: We inhale air rich in oxygen We breathe in air, which is a mixture of gases. It contains oxygen about $21\%$. Since oxygen is the gas our body needs for respiration and it is present in large amounts in the air, we say we inhale air rich in oxygen.
• We often sneeze when we inhale a lot of dust-laden air. What can be possible explanations for this? Ans: We often sneeze when we inhale a lot of dust-laden air because the dust particles irritate the lining of our nose. The nose has tiny hair and mucus that help to trap dust and dirt. But when too much dust enters, it tickles or irritates the inside of the nose and the body tries to remove it by making us sneeze. It helps to clear the nasal passages and prevent harmful particles from reaching the lungs.
• 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. Ans: Anusha may have run faster or for a longer time than Paridhi. So, her body needed more oxygen and she breathed faster to get more oxygen and remove more carbon dioxide. Anusha may not be as fit as Paridhi. If Paridhi is more used to running or exercising, her body does not need to breathe as fast. Anusha's body had to work harder, so she breathed faster.
• Yadu conducted an experiment to test his idea. He took two test tubes, $A$ and $B$ and added a pinch of rice 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 Figure. What do you think he wants to test? Ans:
  
  Yadu's experiment shows that saliva helps to break down starch into simpler substances (sugar) during digestion. Rice flour has starch in it. Iodine solution turns blue-black when it comes in contact with starch. In Test Tube A (without saliva), the iodine turned the solution blue-black, showing that starch is still present. In Test Tube B (with saliva), the iodine did not turn blue-black, showing that saliva has broken down the starch.
• Rakshita designed an experiment taking two clean test tubes, A and B and filled them with lime water as shown in the figure. In test tube A, the surrounding air that we inhale was passed on by sucking air from the pipe and in test tube B, the exhaled air was blown through the pipe. What do you think she is trying to investigate? How can she confirm her findings? Ans:
  
  Inhaled air Exhaled air She wants to see which air (inhaled or exhaled) contains more carbon dioxide by using lime water as an indicator. Lime water turns milky or cloudy when carbon dioxide is passed through it. This is a common test for the presence of ${\mathrm{CO}}_2$.

• In Test Tube A (inhaled air): The lime water will stay clear or show a very slight change because inhaled air has very little ${\mathrm{CO}}_2$.
• In Test Tube B (exhaled air): The lime water will turn milky because exhaled air has more ${\mathrm{CO}}_2$ (produced during respiration).

4.0Key Features of NCERT Solutions Class 7 Science Chapter 9

1. Conceptual Clarity: Explanations follow a logical structure, mirroring the NCERT sequence—starting from basic definitions (e.g., what is life?) to complex processes (like cellular respiration).
2. Labeled Diagrams: The mouth and alimentary canal, lung structure, and the breathing model (diaphragm/pet bottle demo) are clearly illustrated with step labels 
3. Step-by-Step Solutions: Students are guided through multi-step experiments, reasoning questions, and application-based scenarios (e.g., why cows chew cud, lime-water tests for CO₂).
4. Activity-Based Learning: Hands-on activities—like salivary starch breakdown, modeling inhalation/exhalation using rubber-sheet diaphragms, and lime-water experiments—help reinforce theoretical concepts through observation 
5. Differentiated Responses: Questions consider diverse organisms—humans, ruminants, fishes, amphibians—highlighting how life processes adapt to habitat and physiology.
6. Text-Backed Answers: All solutions strictly reference NCERT content, ensuring no extra, irrelevant material—perfect for CBSE-aligned preparation.