Class VII – Science

Chapter 2: Nutrition in Animals

I. Fill in the blanks

1. __________ is the process of taking in food by an organism and its digestion, absorption, and utilization in the body.
   Answer: Ingestion
2. The __________ is a nutrition in which an organism takes in food by feeding upon it and then energy for life processes.
   Answer: Heterotrophic
3. The process of taking food by an organism is called __________.
   Answer: Ingestion
4. The process by which undigested food is removed from the body is called __________.
   Answer: Egestion
5. The food passes through a long muscular canal __________ that begins at the __________ end at the anus.
   Answer: Alimentary canal
6. The glands associated with the alimentary canal are __________ and pancreas.
   Answer: Salivary glands
7. The buccal cavity contains the __________, __________, and __________.
   Answer: Teeth, tongue
8. The salivary glands produce a digestive juice called __________ which breaks down the present in the food into sugars.
   Answer: Saliva
9. The __________ is a fleshy, muscular organ attached at the back to the floor of the buccal cavity.
   Answer: Tongue
10. The process of chewing breaks down the food into small pieces and mixes it with saliva known as __________.
    Answer: Mastication
11. The white and hardest substance that covers the teeth is called __________.
    Answer: Enamel
12. The bacteria present in our mouth react with leftover food and the saliva which forms then, sticky layer called __________.
    Answer: Plaque
13. Plaque, if not removed by brushing forms __________ with the sugar present in the food.
    Answer: Cavities
14. Digestion does not take place in the __________ or __________.
    Answer: Oesophagus, large intestine
15. The pushing down of food by the walls of the oesophagus is called __________.
    Answer: Peristalsis
16. The inner wall of the stomach contains __________ which secrete digestive juices that contain three substances: __________, __________, and __________.
    Answer: Gastric glands, hydrochloric acid, pepsin, mucus
17. __________ kills the bacteria that enter with the food in the stomach.
    Answer: Hydrochloric acid
18. The __________ protects the inner lining of the stomach from the action of the acid.
    Answer: Mucus
19. The small intestine receives secretions from two glands, the __________ and __________.
    Answer: Liver, pancreas
20. The __________ is a reddish-brown gland situated in the upper part of the abdomen.
    Answer: Liver
21. __________ is the largest gland in our body that secretes __________, which is stored in a sac called __________, which helps in the digestion of __________.
    Answer: Liver, bile juice, gallbladder, fats
22. The __________ acts on carbohydrates and proteins and changes them into simpler forms.
    Answer: Pancreatic juice
23. The process of digestion completes in the __________.
    Answer: Small intestine
24. The process of absorption of food occurs in the __________.
    Answer: Small intestine
25. The large intestine has two parts – __________ and the __________. The colon absorbs __________ and __________ from undigested food.
    Answer: Colon, rectum, water, salts
26. The partially digested food in ruminants is called __________.
    Answer: Cud
27. The process in which cud returns to the mouth as small lumps and the animals chew it a second time is called __________.
    Answer: Rumination
28. In animals like horses, rabbits cellulose is digested in a specialized organ called __________, which is a large sac-like structure present between __________ and __________.
    Answer: Caecum, small intestine, large intestine
29. __________ provide a large surface area for the absorption of digested food in the small intestine.
    Answer: Villi
30. __________ is the organ that is involved in the digestion of milk protein in infants.
    Answer: Rennin

II. Name the following

1. Name the part of the alimentary canal that is involved in respectively-
   1. a) Killing of bacteria
      Answer: Stomach
   2. b) Chewing of food
      Answer: Buccal cavity
   3. c) Absorption of digested food
      Answer: Small intestine
2. Name the organ involved in the absorption of water.
   Answer: Large intestine
3. Process of pushing down of food by the oesophagus.
   Answer: Peristalsis
4. Widest part of the alimentary canal.
   Answer: Stomach
5. Longest part of the alimentary canal.
   Answer: Small intestine
6. Largest gland in the body that helps in the digestion of fats.
   Answer: Liver
7. Ends product of digestion of-
   1. a) Carbohydrates
      Answer: Glucose
   2. b) Proteins
      Answer: Amino acids
   3. c) Fats
      Answer: Fatty acids and glycerol
8. Finger-like projection in the inner wall of the small intestine.
   Answer: Villi
9. White and hardest substance that covers the teeth.
   Answer: Enamel
10. Special structure present in the following for the ingestion of food-
    1. a) Human beings
       Answer: Mouth
    2. b) Paramecium
       Answer: Cilia
    3. c) Hydra
       Answer: Tentacles
    4. d) Frog
       Answer: Sticky tongue
    5. e) Insects
       Answer: Proboscis

III. Analogy Based Questions

1. Frog: Sticky tongue:: Insects: __________
   Answer: Proboscis
2. Incisors: __________:: Premolars: 8
   Answer: 4
3. Stomach: __________:: Liver: Reddish brown gland
   Answer: Muscular sac

IV. Correct the underlined word

1. The undigested semisolid waste known as faeces is passed into the colon.
   Answer: Rectum
2. Consumption of unclean water or dirty food results in dehydration.
   Answer: Diseases
3. The carbohydrates get broken down into amino acids.
   Answer: Simple sugars
4. Pancreas is the largest gland in our body.
   Answer: Liver

V. Assertion Based Questions

Use the following key to choose the appropriate answer:

• (a) Both A and R are true and R is the correct explanation of A.
• (b) Both A and R are true but R is not the correct explanation of A.
• (c) A is true but R is false.
• (d) A is false but R is true.

1. Assertion (A): Rumen is the first of four chambers of the stomach of ruminants.
   Reason (R): In rumen, the food gets partially digested and is called cud.
   Answer: (a) Both A and R are true and R is the correct explanation of A.
2. Assertion (A): Liver secretes juice called bile juice.
   Reason (R): Bile juice is stored in the liver.
   Answer: (b) Both A and R are true but R is not the correct explanation of A.
3. Assertion (A): Food is pushed down the food pipe which runs through the neck and chest.
   Reason (R): The peristaltic movement of the wall of the food pipe is a continuous process.
   Answer: (a) Both A and R are true and R is the correct explanation of A.