Page 153 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

v We depend on forest for our survival. Forests maintain a complex ecosystem, comprising

trees that support many types of lives.
v Raymond Lindeman was the first to represent the rate of energy transfer between trophic

levels in a system as a set of mathematical equations.

Exercise

A. Tick (3) the correct answer.
1. Animals depend on plants for ............................... .

(a) Pollination (b) Food (c) Nutrients (d) Minerals
Ans: (b)

2. Humus is produced when ............................... acts upon dead plants and animals.
(a) Sand (b) Microorganisms (c) Wood (d) None of the above

Ans: (b)
3. Which of the following is a forest product?

(a) Plastic (b) Petrol (c) Kerosene (d) Gum
Ans: (d)

4. The lowest layer in the understorey is formed by ............................... .
(a) Shrubs (b) Herbs (c) Trees (d) Tall grasses

Ans: (a)
5. Which one of the following products comes from animals?

(a) Gum (b) Rubber (c) Flowers (d) Honey
Ans: (d)

6. Forests cover ............................... percent of the global land area.
(a) 20 per cent (b) 35 per cent (c) 31 per cent (d) 25 per cent

Ans: (c)
B. Fill in the blanks.

1. Forests protect the soil from soil ............................... .
Ans: erosion

2. Microorganisms act upon the dead plants to produce ............................... .
Ans: humus

3. ............................... are the organisms that feed on dead animals.
Ans: Decomposers

4. Herbs form the ............................... layer of the forest.
Ans: ground

5. Large scale cutting down of trees is called ............................... .
Ans: deforestation

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