THESE NOTES ARE PREPARED ACCORDING TO JKBOSE SYLLABI IN SIMPLIFIED AND CONCISE PATTERN
Exercises
1. Explain how animals dwelling in the forest help it grow and regenerate.
Ans: The animals dwelling in the forest help it to grow in many ways.
Animals, birds and insects help in pollination and dispersion of seeds.
They provide manure to the forest in form of dung.
They eat older vegetation and help grow new vegetation.
The decomposers help in the transfer of nutrients back to soil.
2. Explain how forests prevent floods.
Ans: Forests act as natural absorber of rainwater. They do not allow the rain to hit ground directly but hit canopy to trees, followed by shrubs and herbs.
The roots also hold the soil firmly and absorb the water.
3. What are the decomposers? Name any two of them. What do they do in the forest?
Ans: Decomposers are the living organims that help in decomposition of dead and decaying matter. E.g Fungi, Bacteria.
Decomposers play an important role in the forests. They help in the transfer of nutrients back to the soil.
4. Explain the role of forest in maintaining the balance between oxygen and carbon dioxide in the atmosphere.
Ans: The forests are called earth's lungs. The trees, shrubs, herbs during photosynthesis take in carbon dioxide and release oxygen which is consumed by animals.
The animals inturn release carbon dioxide.
5. Explain why there is no waste in a forest?
Ans: Forests are the dynamic living entities. Everything that is naturally present in the forest is made from organic compounds.
When the plants or animals die or their parts fall, they are readily decomposed by the bacteria anf fungi present in the soil.
6. List five products we get from forests?
Ans: We get timber, firewood, gum, medicine, spices, paper etc from the forest.
7. Fill in the blanks:
a. The insects, butterflies, honey bees and birds help flowering plants in Pollination.
b. A forest is a purifier of Air and Water.
c. Herbs form the Bottom layer in the forest.
d. The decaying leaves and animal droppings in a forest enrich the Soil.
8. Why should we worry about the conditions and issues related to forests far from us?
Ans: Forests are the dynamic living entities. They are natural aquifers and earth's lungs.
They help keep environment clean, produce oxygen, absorb carbon dioxide, bring rainfall, stop floods etc. Hence, we should worry about the forests far away from us.
9. Explain why there is a need for variety of animals and plants in a forest.
Ans: The variety of animals and plants in a forest is called its bio-diversity.
The variety of plants and animals in a forest makes it sustainable as there is more choice in the food web.
More variety also leads to growth of forests.
10. In Fig 17.15, the artist has forgotten to put the labels and directions on the arrows. Mark the directions on the arrows and label the diagram using the following labels:
clouds, rain, atmosphere, carbondioxide, oxygen, plants, animals, soil, roots, watertable.
Ans:
11. Which of the following is not a forest product?
I. Gum II. Plywood III. Sealing wax IV. Kerosene
Ans: Iv. Kerosene
12. Which of the following statements is not correct?
I. Forests protect the soil from erosion.
II. Plants and animals in a forest are not dependent on one another.
III. Forests influence the climate and watercycle.
IV. Soil helps forests to grow and regenerate.
Ans: II. Plants and animals in a forest are not dependent on one another.
13. Micro-organism act upon the dead plants to produce?
i. Sand (ii)Mushrooms (iii)Humus (iv)Wood
Ans: iii. Humus
14. Tickmark the correct choice:
1. Micro-organism which converts dead plants, animals into humus are known as:
(a) Decomposers (b) Omnivores
(c) Herbivores (d) Carnivores
Ans: a. Decomposers
2. Which of the following is not a forest product?
(a) Plywood (b) Gum (c) Teak (d) Gasoline
Ans: d. Gasoline
3. Deforestation results in:
(a) Increase in rainfall
(b) Global warming
(c) Increase in water level
(c) Increase in water level
(D) Conservation of soil
Ans: (b) Global warming
4. A food chain includes:
(a) Producers and herbivores
(b)Producers and carnivores
(c) Producers and decomposers
(d) Producers, herbivores and carnivores
Ans: (d) Producers, herbivores and carnivores
Ans: (b) Global warming
4. A food chain includes:
(a) Producers and herbivores
(b)Producers and carnivores
(c) Producers and decomposers
(d) Producers, herbivores and carnivores
Ans: (d) Producers, herbivores and carnivores
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