Andhra Pradesh SCERT Class 7 Science Chapter 2 Solutions | APSCERT Semester 1
Andhra Pradesh SCERT Class 7 Science 1st Semester Chapter 2 ‘Nutrition in Plants’ Solutions is available in this page.
Board |
Andhra Pradesh SCERT |
Class |
7 |
Subject |
Science |
Semester |
1 |
Topic |
Solutions |
1.) Fill in the blanks:
(a) The main steps of nutrition in humans are __________, __________, __________, _________ and __________.
Ans. Carbohydrate, Protein, Fats, Vitamins, Minerals.
(b) The largest gland in the human body is __________.
Ans. Liver
(c) The stomach releases hydrochloric acid and ___________ juices which act on food.
Ans. digestive
(d) The inner wall of the small intestine has many finger-like outgrowths called _________.
Ans. villi
(e) Amoeba digests its food in the ____________ .
Ans. food vacuole
2.) Mark ‘T’ if the statement is true and ‘F’ if it is false:
(a) Digestion of starch starts in the stomach. (T/F)
Ans. False
S.S. Digestion of starch starts in the mouth.
(b) The tongue helps in mixing food with saliva. (T/F)
Ans. The saliva present in the mouth breaks down the starch into sugars.
(c) The gall bladder temporarily stores bile. (T/F)
Ans. True
This bile juice act as an important role in the digestion of fats
(d) The ruminants bring back swallowed grass into their mouth and chew it for some time. (T/F)
Ans. True
At the time of grazing, they quickly swallow the grass and store it in a part of the stomach. Here the food gets partially digested which is called cud. But later the cud returns to the mouth in small lumps and the animal chews it.
3.) 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
Ans. (iii) small intestine
The complete digestion of food takes place in small intestines. It is highly coiled receives secretions from the liver name as bile juice. This bile juice digests the fat related foods.
(b) Water from the undigested food is absorbed mainly in the
(i) stomach (ii) foodpipe (iii) small intestine (iv) large intestine
Ans. (iv) large intestine
It is the function of the large intestine is to absorb water and some salts from the undigested food materials.
4.) Match the items of Column I with those given in Column II:
Ans.
Column 1 |
Column 2 |
Food components |
Product(s) of digestion |
Carbohydrates |
Sugar |
Proteins |
Amino acids |
Fats |
Fatty acids and glycerol |
5.) What are villi? What is their location and function?
Ans. The inner wall of the small intestine has many finger-like outgrowths known as villi.
Function of Villi:-
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, which are transported via the blood vessels to different organs of the body.
6.) Where is the bile produced? Which component of the food does it help to digest?
Ans. Bile is produced in lever.
It helps to digest fats related food.
7.) Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.
Ans. Cellulose carbohydrate can be digested by ruminants but not by humans.
Humans cannot be digest this type of carbohydrate this is because, in ruminants like cow, buffalo, goat etc. have rumen, a separate compartment of stomach is present in where cellulose is broken. While in human’s stomach that type of compartment is unavailable.
8.) Why do we get instant energy from glucose?
Ans. Glucose is a ready med digested food material obtains after digestion of polysaccharides. After absorption by the villi, glucose easily breaks down in the cells, with the help of O2 into Co2 and H2O, and energy is released. Whereas other carbohydrates are first broken down into glucose in small intestine then absorption will take place, which will take time.
9.) Which part of the digestive canal is involved in:
(i) absorption of food ________.
Ans. Small Intestine
(ii) chewing of food ________.
ans. Teeth
(iii) killing of bacteria ______.
Ans. Mouth (Saliva), Stomach (HCL).
(iv) complete digestion of food ______.
Ans. Small Intestine
(v) formation of faeces _______.
Ans. Anus
10.) Write one similarity and one difference between the nutrition in amoeba and human beings.
Difference:
Amoeba |
Human beings |
Digestive juices are secreted into the food vacuole. |
Digestive juices are secreted into the stomach, small intestine, lever, pancreas etc. |
Similarity
Amoeba |
Human beings |
They absorb food and release energy |
They are also absorb food and release energy |
11.) Match the items of Column I with suitable items in Column II
Ans.
Column I |
Column II |
(a) Salivary gland |
(iii) Saliva secretion |
(b) Stomach |
(iv) Acid release |
(c) Liver |
(i) Bile juice secretion |
(d) Rectum |
(vii) Release of faeces |
(e) Small intestine |
(v) Digestion is completed |
(f) Large intestine |
(ii) Storage of undigested food |
13.) Can we survive only on raw, leafy vegetables/grass? Discuss.
Ans. No, we cannot survive only on raw, leafy vegetables / grass this is because cellulose presents in it, which is unable to digest by the human beings.