class 7 science
Nutrition in animals
(a) The main steps of nutrition in humans are __________, __________, __________, _________ and __________.
(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) foodpipe (iii) small intestine (iv) large intestine
Nutrition in animals
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 ____________ .
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.
(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.
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
(b) Water from the undigested food is absorbed mainly in the
(i) stomach (ii) foodpipe (iii) small intestine (iv) large intestine
4. Match the items of Column I with those given in Column II:
7. Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.
Answer
Cellulose is a type of carbohydrate that can be digested by ruminants and not by humans.
Ruminants have a large sac-like structure called rumen between the oesophagus and the small intestine. The cellulose of the food is digested here by the action of certain bacteria which are not present in humans.
8. Why do we get instant energy from glucose?
Answer
Glucose is simple sugar which is formed when carbohydrate get broken. Also, the carbohydrate get digested into glucose. Since, glucose does not have to be digested and thus acts as an instant source of energy.
9. Which part of the digestive canal is involved in:
(i) absorption of food ________________.
(ii) chewing of food ________________.
(iii) killing of bacteria ________________.
(iv) complete digestion of food ________________.
(v) formation of faeces ________________.
| Column I Food Components | Column II Product(s) of digestion |
| Carbohydrates | Fatty Acids and Glycerol |
| Proteins | Sugar |
| Fats | Amino acids |
Answer
Cellulose is a type of carbohydrate that can be digested by ruminants and not by humans.
Ruminants have a large sac-like structure called rumen between the oesophagus and the small intestine. The cellulose of the food is digested here by the action of certain bacteria which are not present in humans.
8. Why do we get instant energy from glucose?
Answer
Glucose is simple sugar which is formed when carbohydrate get broken. Also, the carbohydrate get digested into glucose. Since, glucose does not have to be digested and thus acts as an instant source of energy.
9. Which part of the digestive canal is involved in:
(i) absorption of food ________________.
(ii) chewing of food ________________.
(iii) killing of bacteria ________________.
(iv) complete digestion of food ________________.
(v) formation of faeces ________________.
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