NCERT Solutions for Class 7 Science Chapter 2
NCERT Solutions for Class 7 Science Chapter 2 Nutrition in Animals or अध्याय 2 प्राणियों में पोषण in Hindi Medium free to download in PDF file or View online. Solutions are based on latest CBSE Text Books for the academic session 2020-2021. The explanation of Chapter 2 in video format is also given in English Medium and Hindi Medium separately. Through these videos all the keywords and important points are described, so that students can study more in less time. MCQ based on 7th Science Chapter 2 and important questions with intext questions and answers are good for terminal test as well as final school examination.Visit to discussion forum and ask Here questions and share with your friends. It is an open forum to discussion about question answers in any language. Download Offline apps based on latest CBSE Syllabus.
NCERT Solutions for Class 7 Science Chapter 2
|Class: 7||Science (English and Hindi Medium)|
|Chapter 2:||Nutrition in Animals|
Class 7 Science Chapter 2 Answers
Class 7 Science Chapter 2 Explanation in Videos
Important Main Point in Class 7 Science Chapter 2
1. Different Ways of Taking Food
We have already studied about the nutrition in plants. This part of the content describes the nutritional needs and digestive system in human beings, along with other living beings. As we know that food is needed for every living organism. Plants can prepare their own food but animals cannot. But we know nutrition is required for every organism for energy. The food contains some nutrients like carbohydrate, protein, fat, vitamin and minerals which are required by our body for growth and development, called ‘Nutrition’. Generally, in the process of nutrition, food is taken as a complex substance and break down in simpler substances, called ‘Digestion’. After that, it is utilised by our body. You may have observed that different types of animals show different modes of nutrition. Such as, eagle tear flesh of prey, hummingbirds suck the nectar from the flower, mosquito and lice suck blood from other organisms. And amoeba capture and swallow tiny aquatic animals, snake-like python swallow others animal on the whole, human and many other animals feed on mother’s milk.
2. Digestion in Human
In this part of the content gives sufficient idea about the journey of food in human beings. As you learnt before in the process of digestion, food is breakdown in simple substances and after it is utilised by our body. The journey of our food starts from the buccal cavity (mouth) then it moves on food pipe or oesophagus and after it reaches to the stomach, small intestine and next to the large intestine and last the anus. Remember, tooth and digestive glands play an important role in our digestion.
3. Process of Digestion
As you know, food is taken through the mouth with the help of teeth food is breakdown. You must know that our mouth has salivary glands. It secrets a juice, called saliva. We use our tongue for talking beside it mixes saliva with the food and helps in swallowing food. The swallowed food passes into the food pipe and reaches into the stomach. You know digestive juices and acids are present in the stomach which helps the food to digest due to some of the physical and chemical changes. Partially digested food reaches the small intestine where intestinal juices complete the digestion. You are surprised to know that our small intestine is 7.5 metres long and highly coiled. Similarly, our large intestine is about 1.5 metre-long, and it helps to remove waste material time-to-time through the anus.
4. Digestion in Grass Eating Animals
You may have observed that cows, buffaloes and other grass-eating animals chewing continuously, even when they are not eating. They quickly swallow the grass and store it in a part of a stomach, called ‘Rumen’. Hence, they are called ruminants. You may know that partially digested food or grass present in the rumen of a cow is called ‘Cud’. When this cud is thoroughly chewed in the mouth of the cow and swallowed again and reaches small intestine for complete digestion and absorption of food.
5. Feeding and Digestion in Amoeba
Have you ever seen amoeba? Your answer will be ‘no’. Do you know amoeba cannot see by naked eyes? Amoeba is single-celled microscopic organisms which are found in pond, lakes and other water sources. The body of amoeba has a finger-like projection called pseudopodia or false feet. It captures food and helps in locomotion of amoeba. Then the captured food break-down into simpler substances for digestion. This digested food is then absorbed and used for growth and maintenance by amoeba. In this way, you can see animals obtain their nutrients through a wide variety of feeding patterns. As nutrition is a must for a variety of reasons. Animals need the proper nutrition for growth, maintenance, transportation of materials and to provide energy for work and vital functions for their survival or existence.
Important Questions for 7th Science Chapter 2
1. The enzymes present in the saliva convert
(a) fats into fatty acids and glycerol.
(b) starch into simple sugars.
(c) proteins into amino acids.
(d) complex sugars into simple sugars.
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 blue-black colour when tested with iodine?
(a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iii) (d) (iii) and (iv)
3. Cud is the name given to the food of ruminants which is
(a) swallowed and undigested.
(b) swallowed and partially digested.
(c) properly chewed and partially digested.
(d) properly chewed and completely digested.
4. The acid present in the stomach
(a) kills the harmful bacteria that may enter along with the food.
(b) protects the stomach lining from harmful substances.
(c) digests starch into simpler sugars.
(d) makes the medium alkaline.
5. Which of the following pair of teeth differ in structure but are similar in function?
(a) canines and incisors.
(b) molars and premolars.
(c) incisors and molars.
(d) premolars and canines.
6. The finger-like outgrowths of Amoeba helps to ingest food. However, the finger-like outgrowths of human intestine helps to
(a) digest the fatty food substances.
(b) make the food soluble.
(c) absorb the digested food.
(d) absorb the undigested food.
7. Read carefully the terms given below. Which of the following set is the correct combination of organs that do not carry out any digestive functions?
(a) Oesophagus, Large Intestine, Rectum
(b) Buccal cavity, Oesophagus, Rectum
(c) Buccal cavity, Oesophagus, Large Intestine
(d) Small Intestine, Large Intestine, Rectum
8. Read the following statements with reference to the villi of 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)
9. The swallowed food moves downwards in the alimentary canal because of
(a) force provided by the muscular tongue.
(b) the flow of water taken with the food.
(c) gravitational pull.
(d) the contraction of muscles in the wall of food pipe.
10. The false feet of Amoeba are used for
(a) movement only.
(b) capture of food only.
(c) capture of food and movement.
(d) exchange of gases only.
Answers of Important MCQ
Important NCERT Questions Class 7 Science Chapter 2
The villi increase the surface area for absorption of the digested food. Each villus has a network of thin and small blood vessels close to its surface. The surface of the villi absorbs the digested food materials.
The bile helps in the digestion of fats.
अंतर: अमीबा में पाचन प्रक्रिया सरल है जबकि मनुष्य में यह एक जटिल प्रक्रिया है। अंतर्ग्रहण और उत्सर्जन की प्रक्रिया भी काफी भिन्न होती है। अमीबा अपने भोजन को पदाभ के माध्यम से पकड़ता है। अवशोषण के पश्चात् बिना पचा हुआ भोजन खाद्यधानी द्वारा बाहर निकल दिया जाता है। जबकि मनुष्यों में, भोजन (जो जटिल पदार्थ है) मुंह के अंदर ले जाया जाता है और पाचन और अवशोषण की एक जटिल प्रक्रिया से गुजरता है। अंत में बचा हुआ पदार्थ मल के रूप में निष्कासित कर देता है।