Chapter 3
Heat
1. Fill in the blanks:
(a) The main steps of nutrition in humans are __________, __________,
__________, _________ and __________.
Ans:
- Ingestion
- Digestion
- Absorption
- Assimilation
- Egestion
(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.
(b) The tongue helps in mixing food with saliva. (T/F)
Ans: True.
(c) The gall bladder temporarily stores bile. (T/F)
Ans: True .
(d) The ruminants bring back swallowed grass into their mouth
and chew it for some time. (T/F)
Ans: True.
(a) Fat is completely digested in the
(i) stomach (ii) mouth (iii) small intestine (iv) large intestine
Ans: (iii) small intestine.
(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.
4. Match the items of Column I with those given in Column II:
Column I Column II
Food components Product(s) of digestion
Carbohydrates Fatty acids and glycerol
Proteins Sugar
Fats Amino acids
Ans:
Column I | Column II |
---|---|
Carbohydrates | Simple sugars |
Proteins | Amino acids |
Fats | Fatty acids and glycerol |
5. What are villi? What is their location and function?
Ans: Villi are finger-like projections which are richly supplied with blood vessels. They are present in the inner lining of the small intestine and help in the absorption of nutrients by increasing the surface area for absorption.
6. Where is the bile produced? Which component of the food does it help to digest?
Ans: Bile is a fluid that is made and released by the liver and stored in the gallbladder. Bile helps with digestion. It breaks down fats into fatty acids, which can be taken into the body by the digestive tract.
7. Name the type of carbohydrate that can be digested by ruminants but
not by humans. Give the reason also.
Ans: Cellulose is a type of carbohydrate that can be digested by ruminants and not by humans. Ruminants have a large sac-like structure called
Ans: Glucose is a simplest form of sugar which is easily absorbed by the blood whereas other carbohydrates are first broken down into glucose and then absorbed. Hence, glucose gives instant 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 ________________.
Ans: (i) Absorption of food: Small intestine.
(ii) Chewing of food: Mouth.
(iii) Killing of bacteria: Stomach.
(iv) Complete digestion of food: Small intestine.
(v) Formation of faeces: Large intestine.
10. Write one similarity and one difference between the nutrition in amoeba
and human beings.
Ans: Similarity between the nutrition in amoeba and human beings is that both are heterotrophs, they derive their nutritions from other organisms. Dissimilarity between them is that human beings have complex digestive system where food gets digested in separate regions while in amoeba food is digested in a food vacuole.
11. Match the items of Column I with suitable items in Column II
Column I Column II
(a) Salivary gland (i) Bile juice secretion
(b) Stomach (ii) Storage of undigested food
(c) Liver (iii) Saliva secretion
(d) Rectum (iv) Acid release
(e) Small intestine (v) Digestion is completed
(f ) Large intestine (vi) Absorption of wate
(vii) Release of faeces
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 | (vi) Absorption of water |
Type by Jyotishna Hazarika
Colour By: Himashree Bora.