Important Questions Class 7 Science Chapter 2

Important Questions Class 7 Science Chapter 2 – Nutrition in Animals

Class 7 Science Chapter 2 is about Nutrition in Animals. In Chapter 1, you have learned that in the heterotrophic mode of nutrition, organisms, including herbivorous, carnivores, and a few fungi depend on plants directly or indirectly for the nutrient requirement. Plants can produce their food through photosynthesis, whereas animals cannot synthesise food, infact many of them depend on plants. 

In Chapter 2, you will learn about the various modes of nutrition in human beings, grass-eating animals like cows, and feeding and digestion in Amoeba. You will also learn about the complex process of nutrition involving the stages: ingestion, digestion, absorption, assimilation and egestion of food.

To score good grades, students preparing for their examinations must understand the topics and practice many questions. For this purpose, the expert panel of Extramarks have curated many study and practice materials such as NCERT Solutions, CBSE Revision notes, NCERT books, and CBSE sample papers. 

A comprehensive list of Chapter 2 Class 7 Important Science Questions is compiled carefully per the CBSE syllabus and NCERT guidelines, helping you understand the examination question pattern. To get maximum benefit, students are suggested to practice these questions rigorously through Science Class 7 Chapter 2 Important Questions available on the Extramarks’ website.

Important Questions Class 7 Science Chapter 2 – With Solutions

By referring to and practising Class 7 Science Chapter 2 Important Questions created by the Extramarks, students gain in-depth knowledge of Chapter 2 clearly and get acquainted with all types of questions, including MCQs short answer questions, long answer questions, etc. These questions and solutions have been gathered from various sources like the NCERT textbook, NCERT exemplar, past year’s examination papers, other sources, etc. Students can register and access this complete list of solutions for Important Questions Class 7 Science Chapter 2 from the Extramarks’ website. 

Below are some Important Questions Class 7 Science Chapter 2 with solutions:

Question 1. Fill in the blanks

 (a)The main steps of nutrition in humans are __________, __________,  __________,  _________ and __________.

(b) The largest gland in the human body is __________.

(c) The stomach releases hydrochloric acid and ___________ juices which act on food.

(d) The inner wall of the small intestine has many finger-like outgrowths called _________.

(e) Amoeba digests its food in the ____________.

 Answer 1.  

(a) Ingestion, Digestion, Absorption, Assimilation, Egestion

(b) Liver

(c) Digestive

(d) Vill

(e) Food vacuole

Question 2. Given below from (i) to (iv) are some food items.

(i)  Boiled and mashed potato

(ii) Glucose solution

(iii) A slice of bread

(iv) Mustard oil

Which of the above will give a blue-black colour when tested with iodine?

(a) (i) and (ii) 

(b) (i) and (iii)

(c) (ii) and (iii)  

(d) (iii) and (iv)

Answer 2. (b) i and iii

Explanation: Boiled, mashed potato and bread slices contain starch (carbohydrates). Hence, when a few drops of iodine solution are added, it turns into a blue-black colour.

Question 3. Describe the location and function of the Salivary gland?

Answer 3. The salivary gland is present in the buccal cavity. It secrets saliva for food digestion and helps keep the oral cavity and mouth healthy.

Question 4. Mark ‘T’ if the statement is true and ‘F’ if it is false

(a) Digestion of starch starts in the stomach. (T/F)

(b) The tongue helps in mixing food with saliva. (T/F)

(c) The gall bladder temporarily stores bile. (T/F)

(d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (T/F)

Answer 4. 

 (a) F, digestion of starch starts from the buccal cavity

 (b) T

 (c) T       

 (d) T  

Question 5. Read carefully the terms given below. Which of the following sets is the correct combination of organs that do not perform digestive functions?

(a) Oesophagus, Large Intestine, Rectum

(b) Buccal cavity, Oesophagus, Rectum

(c) Buccal cavity, Oesophagus, Large Intestine

(d) Small Intestine, Large Intestine, Rectum

Answer 5. (a) Oesophagus, Large Intestine, Rectum. These organs are not directly involved in digestion as,

• The oesophagus is a straight muscular tube through which food passes down to the stomach.
• The large intestine absorbs minerals, water and some remaining nutrients from the undigested food. The leftover waste is converted into stools.
• The rectum stores the stools and is the end part of the large intestine.

Question 6. Explain the types of teeth and their functions in humans?

Answer 6. There are four types of teeth present in human beings:   

• Incisors: Incisors are flat, sharp teeth with a thin edge present at the front of the mouth. They are also referred to as anterior teeth. There are eight incisor teeth in humans.

Function: They help in biting and cutting the food into smaller pieces.

• Canines: Canines are the longest teeth that are sharp and pointed. There are four of them placed next to Incisors. They are also called cuspids or eyeteeth. 

Function: Used to tear the food.

• Premolars: Placed next to canines are premolars. These are bigger than incisors and canines. Eight premolars are found in adults, whereas children below ten do not have them. 

Function: Chewing and grinding of food is done by premolars.

• Molars: Biggest of all the teeth, molars have flat surfaces with ridges. Adults have twelve permanent molars, and children have eight primary molars.

Function: Chewing and grinding of food.

Question 7. Which part of the digestive canal is involved in:

(a) absorption of food ________________

(b) chewing of food ________________

(c) killing of bacteria ________________

(d) complete digestion of food ________________

(e) formation of faeces ________________

Answer 7. 

(a) Small intestine 

(b) Teeth 

(c) Stomach 

(d) Small intestine 

(e) Large intestine 

Question 8. Read the following statements about the villi of the small intestine.

 (i) They have very thin walls.

 (ii) They have a network of thin and small blood vessels close to the surface.

 (iii) They have small pores through which food can easily pass.

 (iv) They are finger-like projections.

Identify those statements which enable the villi to absorb digested food.

(a) (i), (ii) and (iv) 

(b) (ii), (iii) and (iv)

(c) (iii) and (iv) 

(d) (i) and (iv)

Answer 8. (a)  i, ii, and iv

Question 9. Explain the Digestion and absorption process in humans?

Answer 9. The digestion and absorption process is explained below:

Digestion: Digestion takes place in the stomach and small intestine with the help of digestive juices. The stomach gradually empties its contents, called chyme, into the small intestine. The muscles of the small intestine mix food with digestive juices from the pancreas, liver, and intestine, for further digestion. The liver secretes bile juice for the digestion of fats and does not contain enzymes. Pancreatic juice is secreted by the pancreas that contains enzymes for the digestion of carbohydrates, proteins, and lipids. Further, the breakdown of these nutrients into simple components like glucose, amino and fatty acids, etc., is done by the enzymes of intestinal juice.

Absorption: Small intestine is lined up with finger-like projections called villi. Villi consist of blood vessels for nutritional absorption. The digested food molecules are passed down to the blood streams through these blood vessels. 

Question 10. The following statements describe the five steps in animal nutrition. Read each statement and give one word for each statement. Write the terms that describe each process.

 (a) Transportation of absorbed food to different body parts and their utilisation.

 (b) Breaking of complex food substances into simpler and soluble substances.

 (c) Removal of undigested and unabsorbed solid residues of food from the body.

 (d) Taking food into the body.

 (e) Transport of digested and soluble food from the intestine to blood vessels.

 Answer 10. 

(a) Assimilation 

(b) Digestion 

(c) Egestion 

(d) Ingestion

(e) Absorption 

Question 11. What are the simple forms of carbohydrates, fats, and proteins?

Answer 11: The complex components of carbohydrates, fats, and proteins are digested in the intestine into simple units as:

Carbohydrates – Glucose /Sugar

Fats – Fatty acids and glycerol

Proteins – Amino acids 

Question 12. Match the items of Column I with suitable items in Column II

Answer 12.           

Question 13. Read the following passage carefully and answer the questions that follow it.

Bile juice is stored in a sac called the gallbladder, located near its organ of secretion, the liver. liver releases the bile juice into the small intestine whenever food reaches there. Though bile juice lacks any digestive enzymes, it is required to digest fats. The fats cannot be digested easily because they are insoluble in water and are present as large globules. Bile juice breaks down big fat droplets into smaller droplets. These are then easily digested by the enzymes released from

the pancreas.

(a) Which organ secretes the bile juice?

(b) Why is digestion of fats difficult compared to other nutrients?

(c) How does bile juice help in the digestion of fat?

(d) Where is the digestion of fat completed?

(e) Does bile juice digest fat completely?

 Answer 13. 

(a) Liver

(b) Fat is insoluble in water.

(c)  Breaks down big fat droplets into smaller droplets.

(d)  Small intestine

(e)  No

Question 14. How is food prevented from entering the windpipe?

Answer 14. Epiglottis is a small flap-like valve that folds over the windpipe and guides the food into the food pipe when the tongue pushes the food into the throat.

Question 15. Fill in the blanks using the words listed below. water, front, intestinal, salts,  pseudopodia, back, vacuole

(a)   The digestion of all food components is completed by the ____________ juice.

(b) Large intestine absorbs ___________ and some __________from the undigested food.

(c) Tongue is attached at the _____________ to the floor of the mouth cavity and is free at  the _____________

(d) Amoeba pushes out _____________ around the food and traps it in a food _____________.

Answer 16.  

(a) intestinal 

(b) water, salts 

(c) back, front

(d) pseudopodia, vacuole  

Question 17. Write one similarity and one difference between the nutrition of Amoeba and human beings.

Answer 17. The below table shows the similarity and differences in nutrition in Amoeba and human beings.

Question 18. Can we survive only on raw, leafy vegetables/grass? Discuss.

Answer 18. No, human beings cannot survive only on raw, leafy vegetables or grass for the following reasons:

• Human beings require all essential nutrients like carbohydrates, proteins, lipids, vitamins and minerals for survival.
• Raw, leafy vegetables or grass do not provide the required nutrients to the body, leading to less immunity and risk of catching diseases.
• Sometimes, raw vegetables contain harmful germs and viruses, making them unfit to consume.

Question 19. Match the animals in Column I with their mode of feeding listed in Column II                     

Answer 19.       

Question 20. Describe the importance of rumen in ruminants.

Answer 20. The rumen is a part of the stomach of ruminants, including the grass-eating animals like cows, buffaloes, deer, and goats. Ruminants rapidly swallow the grass and store it in the rumen, where the food is partly digested. This partly digested food called Cud returns to the mouth in small portions, and the animal chews it continuously. Rumen contains certain bacteria which play an essential role in the digestion of cellulose. 

Question 21. Why do we get instant energy from glucose?

Answer 21. Glucose, when taken directly, gets easily absorbed into the bloodstream and cells. Following the oxidation process in the cell, a high-energy molecule called Adenosine Triphosphate (ATP) is released, providing energy to the cell, resulting in instant energy. 

Question 22. Choose the odd one out from each group and give reasons.

 (a) Liver, salivary gland, starch, gallbladder

 (b) Stomach, liver, pancreas, salivary gland

 (c) Tongue, absorption, taste, swallow

 (d) Oesophagus, small intestine, large intestine, rectum

Answer 22.  

 (a) Starch; others are glands.

 (b) Stomach; others are digestive glands.

 (c) Absorption; others are parts of the mouth.

 (d) Small intestine; no juices are released by other parts/no digestion in other parts.

Question 23. Describe the nutrition process in Amoeba.

Answer 23. The nutrition process in Amoeba is known as phagocytosis. It involves:

• Ingestion: An amoeba is a unicellular organism and does not have a mouth. It ingests food using pseudopodia(a temporary figure-like projection) to engulf the entire organism with some water and form a vacuole.
• Digestion: Digestive enzymes are released in the vacuole to break down the complex food components into small, soluble molecules.
• Absorption: The digested food is absorbed by the cytoplasm, and the food vacuole disappears after diffusion.
• Assimilation: The energy released from food after absorption is used for growth and body functions.
• Egestion: The undigested food in the food vacuole moves near the cell membrane, resulting in the rupture, and the waste is expelled. 

Question 24. Tick (√) mark the correct answer in each of the following:

(a) Fat is completely digested in the

(i) stomach (ii) mouth (iii) small intestine (iv) large intestine

(b) Water from the undigested food is absorbed mainly in the

(i) stomach (ii) food pipe (iii) small intestine (iv) large intestine

Answer 24. 

(a) Fat is completely digested in the:

(i) stomach (ii) mouth (iii) small intestine (√) (iv) large intestine

(b) Water from the undigested food is absorbed mainly in the:

(i) stomach (ii) food pipe (iii) small intestine (iv) large intestine(√) 

Question 25. Choose the correct order of terms that describes the process of

nutrition in ruminants.

(a) Swallowing → partial digestion → chewing of Cud →

complete digestion

(b) Chewing of Cud → swallowing → partial digestion →

complete digestion

(c) Chewing of Cud → swallowing → mixing with digestive

juices → digestion

(d) Swallowing → chewing and mixing → partial digestion

→ complete digestion

Answer 25. (a) Swallowing → partial digestion → chewing of Cud →

complete digestion

Explanation:  Ruminants rapidly swallow the grass and store it in the rumen, where the food is partly digested. This partly digested food called Cud returns to the mouth in small portions, and the animal chews it continuously. Rumen contains certain bacteria which play an essential role in the complete digestion of cellulose.

Question 26. The false feet of Amoeba is used for

(a) Movement only.

(b) Capture of food only.

(c) Capture of food and movement.

(d) Exchange of gases only.

Answer 26. (c) The capture of food and movement.

Explanation: Amoeba feeds on some microscopic organisms. When it senses food, it pushes out one or more finger-like projections (pseudopodia) around the food particle and engulfs it.

Benefits of Solving Important Questions Class 7 Science Chapter 2

To score well in CBSE examinations, students must understand the topics thoroughly and practise the questions. By practising MCQs, short answers, medium answer, and long answer questions provided with step-by-step solutions, students will get well versed with the question pattern and mark weightage of chapter 2. Furthermore, the benefits of referring to Important Questions Class 7 Science Chapter 2 are:

• It covers all the chapter-end questions along with their comprehensive answers explained with proper instances.
• These solutions help students save time while preparing for the upcoming examination as students don’t have to waste time looking for different resources for their exam preparation. Extramarks proves to be a one stop solution
• The questions are collated from various sources, including NCERT Textbooks, CBSE Sample papers, CBSE Extra questions, NCERT Exemplars, past years’ question papers and other sources.
• The question and answers are as per the latest CBSE syllabus and CBSE guidelines. 
• By practising these advanced levels of questions thoroughly through Important Questions Class 7 Science Chapter 2, students not only brush up on the concepts thoroughly but also analyse their shortcomings and overcome them before facing the examinations.
• To refer to and practice the Important Questions Class 7 Science Chapter 2, students must register on the Extramarks’ website. 

Furthermore, students can access various other study materials by clicking on the below links:

• NCERT books
• CBSE Revision Notes
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• Important formulas 
• CBSE extra questions