A. Fill in the blanks:
1. The main steps of nutrition in humans are ……………… , ……………….. , ……………… , …………… , and ………… .
2. The largest gland in the human body is ………………… .
3. The stomach releases hydrochloric acid and ……………. juices which act on food.
4. The inner wall of the small intestine has many finger-like outgrowths called ………………. .
5. Amoeba digests its food in the ………………. .
6. All ruminants are ……………………. .
7. ……………… is the true stomach in ruminants.
B. State ‘True’ or ‘False’:
1. Digestion of starch starts in the stomach. ………………..
2. The tongue helps in mixing food with saliva. ……………..
3. The gall bladder temporarily stores bile. …………….
4. The ruminants bring back swallowed grass into their mouth and chew it for sometime. ……………..
5. Saliva changes sugar into starch. …………………
6. Digestive juices are secreted by oesophagus. ……………….
C. Tick (œ“) the correct option:
1. Fat is completely digested in the:
(a) stomach
(b) mouth
(c) small intestine
(d) large intestine
2. Water from the undigested food is absorbed mainly in the
(a) stomach
(b) food pipe
(c) small intestine
(d) large intestine
3. Which of the acid is secreted in the stomach?
(a) Hydrochloric acid
(b) Nitric acid
(c) Sulphuric acid
(d) Phosphoric acid
4. Bile is produced by :
(a) liver
(b) gall bladder
(c) pancreas
(d) small intestine
5. Faeces are expelled out of the body through:
(a) caecum
(b) rectum
(c) anus
(d) villi
6. In human body, salivary glands are present in:
(a) liver
(b) stomach
(c) mouth
(d) none of these
D. Match the items of Column I with those given in Column II:
| Column I | Column II |
| Food components | Products of digestion |
| 1. Carbohydrates | a. Fatty acids and glycerol |
| 2. Proteins | b. Sugar |
| 3. Fats | c. Amino acids |
E. Answer the following questions in short:
1. What are villi? What is their location and function?
2. Where is the bile produced? Which component of the food does it help to digest?
3. Name the type of carbohydrate that can be digested by ruminants but not by humans. Give the reason also.
4. Why do we get instant energy from glucose?
5. 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
6. Write one similarity and one difference between the nutrition in amoeba and human beings.
7. Label the given fig. of the digestive system.
8. Can we survive only on raw, leafy vegetables/grass? Discuss.
9. What is tooth decay? How can.you prevent it?
10. Animals such as cows can digest grass but humans cannot. Do you agree? Give reasons.
11. Ruminants such as cows and buffaloes swallow their food hurriedly and then sit restfully and chew their food. Can you reason why?
12. Sometimes when we are having a meal, we feel choked, get hiccups or start coughing. Why?
F. Match the items of Column I with suitable items in Column II:
| Column I | Column II |
| 1. Salivary gland | a. Bile juice secretion |
| 2. Stomach | b. Storage of undigested food |
| 3. Liver | c. Saliva secretion |
| 4. Rectum | d. Acid release |
| 5. Small intestine | e. Digestion is completed |
| 6. Large intestine | f. Absorption of water |
| g. Release of faeces |
G. Read the given paragraph carefully and fill in the blanks from the words given in the box:
liver, gall bladder, glycerol, fatty acids, fats
The …………… secretes the bile juice which is stored in the …………….. .The bile breaks up ………….. into tiny droplets that can be digested and absorbed more easily. The digestive juices then act on these tiny droplets to form simpler compounds known as ……………. and ……………. .
H. Visit a doctor and find out:
1. Under what conditions does a patient need to be on a drip of glucose?
2. Till when does a patient need to be given glucose?
3. How does glucose help the patient recover?
I. Find out what vitamins are and get the following information.
1. Why are vitamins necessary in the diet?
2. Which fruits or vegetables should be eaten regularly to get vitamins?
Write a note on the information collected by you. You may take help of a doctor, a dietician, your teacher or any other person, or from any other source.
J. Collect data from your friends, neighbours and classmates to know more about ‘milk teeth’.
Tabulate your data:
K. What is the type of food and mode of feeding of the following animals? Write down your observations in the given table. You may find the list of modes of feeding given below the table helpful:
Table: Various modes of feeding
(Scraping, chewing, siphoning, capturing and swallowing, sponging, sucking etc.)
L. Wash your hands. Look into the mirror and count your teeth. Use your index finger to feel the teeth. Record your observations in the table given below:
M. Observe the figure given below of the four different types of teeth in human. Name them:
N. Look at the figure below and label the parts of foodpipe:
