Class 7 Science Chapter 9: Life Processes in Animals Solutions

1. Multiple choice questions.

1. Which of the following is NOT a part of the human digestive system?

• (a) Mouth
• (b) Oesophagus
• (c) Lungs
• (d) Stomach

Answer: (c) Lungs.

2. The exchange of oxygen and carbon dioxide in humans takes place in

• (a) Intestine
• (b) Lungs
• (c) Liver
• (d) Heart

Answer: (b) Lungs.

3. In grass-eating animals like cows and goats, partially digested food returned to the mouth is known as:

• (a) Chyme
• (b) Bile
• (c) Cud
• (d) Bolus

Answer: (c) Cud.

4. In fish, exchange of gases occurs through:

• (a) Lungs
• (b) Skin
• (c) Gills
• (d) Tracheae

Answer: (c) Gills.

2. Answer the following questions in about 30 words.

1. Name the major life processes in animals.

Answer: The major life processes in animals are nutrition, circulation, respiration, excretion, and reproduction. These processes are essential for the survival and proper functioning of all living beings.

2. What is the primary function of the small intestine in humans?

Answer: The primary function of the small intestine in humans is to absorb digested nutrients from the food. The walls of the small intestine have numerous villi that help in efficient absorption into the blood.

3. What are ruminants? Give an example.

Answer: Ruminants are grass-eating animals that chew their food partially, swallow it, and bring it back to the mouth to chew again. Examples are cows and goats.

4. What is the primary role of the circulatory system?

Answer: The primary role of the circulatory system is to transport nutrients and oxygen to all parts of the body and remove waste products.

3. Answer the following questions in about 150 words.

1. Explain the process of digestion in humans, mentioning the parts involved.

Answer: Digestion in humans begins in the mouth, where food is chewed and mixed with saliva. It then passes through the oesophagus to the stomach, where gastric juices further break down the food. From the stomach, food moves into the small intestine, where the liver and pancreas add digestive juices. The majority of the nutrients are absorbed through the walls of the small intestine. Undigested food moves to the large intestine, where water and some salts are absorbed. Finally, waste is expelled through the anus. The major organs involved in digestion are the mouth, oesophagus, stomach, small intestine, large intestine, anus, liver, and pancreas.

2. Describe the mechanism of breathing in humans and list differences between breathing and respiration.

Answer: Breathing in humans involves the movement of air into and out of the lungs. During inhalation, the diaphragm contracts and pulls down, increasing lung space and allowing air to enter. During exhalation, the diaphragm relaxes, and air is pushed out. The actual exchange of gases (oxygen and carbon dioxide) occurs in the alveoli of the lungs. Breathing is a physical process, while respiration is a chemical process where cells use oxygen to break down glucose and release energy, water, and carbon dioxide.

3. Match the following.

Life Processes in Animals: Class 7 Science Chapter 9 Overview

Understanding life processes such as nutrition, circulation, respiration, excretion, and reproduction is essential for scoring high in exams. Mastering these concepts will help you grasp the vital processes that ensure the survival of humans and other animals.

Chapters like digestive system and breathing mechanism introduce important terms such as alimentary canal, small intestine, and gills. Focus on differences between physical and chemical processes like breathing and respiration for conceptual clarity.

Review chapter highlights and diagrams to boost understanding. Regular revision of NCERT topics and exercise questions will ensure you retain facts and score well in your Class 7 Science tests.