Page 19 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

v Amoeba is a unicellular (single celled) microscopic organism that protrudes finger-like

projections called pseudopodia for locomotion and capturing of food.
v Amoeba engulfs food with the help of pseudopodia and takes the food particle inside the

body which becomes a food vacuole. Digestive juices are secreted here and the complex
food is broken into simpler forms. It is then absorbed and used to carry out various life
processes. After absorption, amoeba throws out the undigested food by rupturing its cell

membrane.
v William Beaumont, a surgeon in the US army was the first to observe the working of the

human digestive system.

Exercise

A. Tick (3) the correct answer.
1. Nutrition in animals includes ....................... .

(a) Nutrient requirement (b) Mode of intake of food
(c) Utilisation of food in body (d) All of the above

Ans. (d)
2. Bile juice is responsible for the digestion of ....................... .

(a) Fats (b) Proteins (c) Vitamins (d) Both (a) and (b)
Ans. (a)

3. The pancreatic juice acts on ....................... .
(a) Carbohydrate (b) Fats (c) Proteins (d) All of the above

Ans. (d)
4. The breakdown of complex components of food into simpler substances is called

....................... .
(a) Digestion (b) Nutrition (c) Breathing (d) Respiration

Ans. (a)
5. In which part of the body does the digestion of protein begin?

(a) Pancreas (b) Stomach
(c) Small intestine (d) Large intestine

Ans. (b)
6. The digestive juice secreted by the liver is called ....................... .

(a) Saliva (b) Mucous (c) Bile (d) Insulin
Ans. (c)

B. Fill in the blanks.
1. The acid present in the stomach is ....................... .

Ans. hydrochloric acid

19