Nutrition in Animals - Class 7 science | Short Answer Type Questions

 

Science - Chapter 2 - Nutrition in Animals

Class - 7

NCERT -  Important Questions 

Short Answer Type Questions

 

Question 1. What does animal nutrition include?

Answer: Animal nutrition includes nutrient requirement, mode of intake of food and its utilisation in the body.

 

Question 2. What do you mean by animal nutrition?

Answer: Animal nutrition includes nutrient requirement, mode of intake of food and its utilisation in the body.

 

Question 3. What are the different modes of feeding in animals?

Answer: Scraping, chewing, brewing, capturing and swallowing, sucking etc. are the different mode of feeding in animals.

 

Question 4. What is digestion?

Answer: The breakdown of complex components of food into simpler substances is called digestion.

 

Question 5. Name the glands that secrete digestive juices.

Answer: Glands associated such as salivary glands, the liver and the pancreas secrete digestive juices.

 

Question 6. What is diarrhoea?

Answer: Sometime we may have experienced the need to pass watery stool frequently. This condition is known as diarrhoea.

 

Question 7. What is ORS?

Answer: Boiled and cooled water with a pinch of salt and sugar dissolved in it is called Oral Rehydration Solution (ORS).

 

Question 8. Where is the bile produced? Which component of the food does it help to digest?

Answer: Bile is produced in liver. The bile plays an important role in the digestion of fats.

 

Question 9. What are ruminant animals?

Answer: The grazing animals like cows, buffaloes and deer are known as ruminants.

 

Question 10. Where is the pancreas located in human body?

Answer: The pancreas is a large cream coloured  gland located just below the stomach.

 

Question 11. How does an amoeba capture its food?

Answer: Amoeba captures its food with the help of finger-like projections, called pseudopodia or false feet.

 

Question 12. What do pancreatic juices digest?

Answer: The pancreatic juice acts on carbohydrates, fats and proteins and changes them into simpler forms.

 

Question 13. What is absorption in terms of digestion?

Answer: The digested food passes into the blood vessels in the wall of the intestine. This process is called absorption.

 

Question 14. What do you mean by rumination?

Answer: A process in which partially digested food returns to the mouth in small lumps and the animal chews it is called rumination.

 

Question 15. What is cud?

Answer: Cud is partly digested food returned from stomach (called rumen) of ruminants to the mouth for further chewing.

 

Question 16. What are milk teeth?

Answer: The first set of teeth grows during infancy and they fall off at the age between six to eight years. These are termed milk teeth.

 

Question 17. What are the major culprits of tooth decay?

Answer: Chocolates, sweets, soft drinks and other sugar products are the major culprits of tooth decay.

 

Question 18. Why do we get instant energy from glucose?

Answer: In the cells, glucose breaks down easily with the help of oxygen into carbon dioxide and water, and energy is released.

 

Question 19. What are the main parts of the alimentary canal?

Answer: The canal can be divided into various compartments:

(1) the buckle cavity, (2) food pipe or oesophagus, (3) stomach, (4) small intestine, (5) large intestine ending in the rectum and (6) the anus.

 

Question 20. How is food prevented from entering the windpipe?

Answer: During the act of swallowing a flap-like valve closes the passage of the windpipe and guides the food into the food pipe. If, by chance, food particles enter the windpipe, we feel choked, get hiccups or cough.

 

Question 21. What is small intestine?

Answer: The small intestine is highly coiled and is about 7.5 metres long. It receives secretions from the liver and the pancreas. Besides, its wall also secretes juices.

 

Question 22- What do you mean by animal nutrition?

Answer: Animal nutrition includes requirement of nutrients, mode of intake of food, and its utilization in the body.

 

Question 23- What is digestion?

Answer: Digestion is the process of breakdown of complex components of food such as carbohydrates into simpler substances that is absorbed and assimilated in the body.

 

Question 24- Name different modes of feeding in animals?

Answer: Scraping, chewing, brewing, capturing and swallowing, sucking etc. are the different mode of feeding in animals.

 

Question 25- What are villi? What are their location and function?

Answer: The inner wail of the small intestine has thousands of finger-like outgrowths called villi.

These are found in small intestine. The villi increase the surface area for absorption of food.

 

Question 26- Where is the bile produced? Which component of the food does it digest?

Answer: Bile is produced in the liver and is stored in a sac called the gall bladder. The bile plays an important role in the digestion of fats.

 

Question 27- Name the type of carbohydrates that can be digested by ruminants but not by humans, Give the reasons also.

Answer: Cellulose is the carbohydrate that can be digested by ruminants. Ruminants have large sac like structure between the small intestine and large intestine. The cellulose of the food is digested by the action of certain bacteria which are not present in human beings.

 

Question 28- Why do we get instant energy from glucose?

Answer: Because glucose easily breakdown in the cell with the help of oxygen and give carbon dioxide, water and energy

 

Question 29- What are Milk teeth and permanent teeth?

Answer: The first set of teeth grows during infancy and they fall off at the age between six to eight years. These are termed as milk teeth.

The second set that replaces them are the permanent teeth. The permanent teeth may last throughout our life or fall off during old age.

 

Question 30- Name the main organs of digestive system.

Answer: The main organs of digestive system are liver, Gall bladder Stomach, Pancreas, Small intestine, Large intestine, Rectum, Anus. The digestive tract and the associated glands together constitute the digestive system.

 

Question 31- Glucose is considered as the source of instant energy, why?

Answer: Glucose is the simplest form of carbohydrate that can be easily broken down to give energy. Hence, we get instant energy from glucose. Also, glucose mixes directly into the blood stream making it readily available to the body.

 

Question 32- What is mastication?

Answer: Mixing of saliva with chewed food is called mastication, this moisten the food and helps in swallowing food.

 

Question 33- Define peristalsis?

Answer: The powerful muscles in oesophagus gently push food down to the stomach in a wave like action which is called peristalsis.

 

Question 34- What do you mean by absorption in terms of digestion of food?

Answer: The food after digestion in stomach passes into the blood vessels in the wall of the intestine. This process is called absorption.

 

Question 35- What role does villi performs in the small intestine?

Answer: The villi increase the surface area for absorption of the digested food. The surface of the villi absorbs the digested food materials and passes them into blood. The absorbed substances are transported via the blood vessels to different organs of the body.

 

Question 36- What is rumination?

Answer: A process in which partially digested food returns to the mouth in small lumps and the animal chews it is called Rumination, and such types of animals are called Ruminants.

 

Question 37-  Write  one similarity and one difference between the nutrition in amoeba and human beings.  

Answer:

Similarity: Both amoeba and human beings use digestive juices for digestion of food.

Difference: Humans need to chew food whereas in amoeba, there is no chewing of food.

 

Question 38- What is the site of production of bile? Which component of the food does it digest?

Answer: Bile is produced in liver and is stored in a sac like structure called the gall bladder.

The bile plays an important role in the digestion of fats, it acts on fat and convert them into simpler form.

 

Question 39- What is the role of pseudopodia in amoeba’s life?

Answer: Pseudopodia helps amoeba in movement and capture of food, it is also called as false feet.

 

Question 40- What happens to the food in large intestine of the digestive tract?

Answer: The food that remains undigested and unabsorbed enters into the large intestine from small intestine. It is about 1.5 metre in length.

Its function is to absorb water and some salts from the undigested food material.

 

Question 41: Why does food need to be digested?

Answer:  The food needs to be digested so that it can be converted into simple soluble forms. These simple soluble forms can provide energy to the body.

 

Question 42:  Digestion of food in all animals occurs inside the body. Do you agree? Justify your Answer.

Answer:  No, digestion does not occur inside the body in all organisms. Certain animals such as spiders inject their digestive juices in the body of their prey. These juices digest the different body parts of the insect and it is then consumed by spider. This process is called external digestion. Thus, all animals do not show digestion inside their bodies.

 

Question 43: In which two organs does digestion of food in humans mainly occur?

Answer: Most of the digestion in humans occur in stomach and small intestine. The stomach performs digestion by peristalsis and with the help of digestive juices. Small intestine, on the other hand, digests food primarily with the help of digestive juices.

 

Question 44: Absorption of digested food occurs in the stomach. Do you agree? Justify your Answer.

Answer:  No, the absorption of food does not occur in the stomach. The food that has been digested in the stomach is further digested into absorptive form in the small intestine. The completely digested food is absorbed by the inner lining (villi) of the small intestine.

 

Question 45: All digestive juices are secreted by cells in the stomach and small intestine. Do you agree? Give reasons.

Answer:  No, all digestive juices are not secreted by the cells of small intestine and stomach. Certain organs such as liver and pancreas also secrete digestive juices. The liver secretes bile juice which is used for the digestion of fats. Pancreas, on the other hand, produces pancreatic juice which digest starch and proteins into their simpler constituents.

 

Question 46: What happens to food after it is digested, and absorbed by the blood?

Answer: The food that has been digested and absorbed is assimilated by the body. The absorbed food is transported by the blood to different parts of the body. This absorbed food is used by the cell for growth, reproduction and obtaining energy. Some of the absorbed food is also stored for future use.

 

Question 47: In what way is the basic structure of the stomach of a cow different from the stomach of a human?

Answer:  

* The stomach of cows is composed of four chambers unlike human stomach which has a single chamber.

* The food in cows is firstly introduced in the first chamber of the stomach called rumen. In rumen, partial digestion of food occurs and the partially digested food is called cud.

* Thereafter, it is passed to the second chamber, from where it is reintroduced into the mouth for proper chewing. Followed by proper chewing, the remaining chambers of the stomach carry out complete digestion of food.