12. Forests: Our Lifeline

Q1. Explain how animals dwelling in the forest help it grow and regenerate.

Ans:

1. Animals help in seed dispersal of certain plants which helps the forest to grow & regenerate . 
2. The decaying animal dung also provides nutrients to the seedlings to grow.
3. Decomposers help in maintaining the supply of nutrients to the plants.
4. More herbivores means more food for carnivores.

Q2. Explain how forests prevent floods.

Ans:

1. Forests are natural abosrber of rainwater & allows it to seep.
2. Roots of trees in the forests absorb rainwater, which reduces surface runoff.
3. Tree canopies don't allow the raindrops to directly hit the forest floor by dripping the rainwater slowly.

4. Thus, if trees are not present, rain will hit the ground directly flood the area around it.

Q3. What are decomposers? Name any two of them. What do they do in the forest?

Ans:

1. The micro-organisms which convert the dead plants & animals to humus are known as decomposers. 
2. They recycle nutrients back into the soil, which is absorbed by the roots of the living plants.
3. Two examples are fungi like mushroom & bacteria.

Q4. Explain the role of forests in maintaining the balance between oxygen and carbon dioxide in the atmosphere.

Ans:

1. Plants release oxygen & use carbon dioxide during photosynthesis.
2. This oxygen is required by animals for respiration. 
3. Thus, the forests maintain a balance of oxygen & carbon dioxide in the atmosphere.

Q5. Explain why there is no waste in a forest.

Ans:

1. In the forest, decomposers break down & convert the dead & decaying matter into humus.
2. This humus is used by living plants as nutrition.
3. This cycle ensures that nothing goes to waste, as all materials are reused.

Q6. List five products we get from forests.

Ans:

1. Timber for building and furniture.
2. Fruits like apples and berries.
3. Medicinal plants used for health treatments.
4. Rubber from rubber trees.
5. Paper made from wood pulp.

Q7. Fill in the blanks:

Ans:

(a) The insects, butterflies, honeybees, and birds help flowering plants in pollination.

(b) A forest is a purifier of air and water.

(c) Herbs form the lowest layer in the forest.

(d) The decaying leaves and animal droppings in a forest enrich the soil.

Q8. Why should we worry about the conditions and issues related to forests far from us?

Ans:

We should worry about the conditions in the forest because deforestation can lead to:

1. Global warming due to increase of carbon dioxide in the atmosphere.
2. Soil erosion.
3. Flooding.
4. Increase of Earth's temperature. 
5. Animal life will be affected which may lead to extinction of species.
6. This will in turn affect the human life.

Q9. Explain why there is a need for a variety of animals and plants in a forest.

Ans:

1. A variety of plants & animals are needed for the forests to regenrate & grow.
2. Decomposers convert dead & decaying matter into nutrients for living plants.
3. Plants serve as food for herbivores which serve as food to carnivores.
4. All food chains need variety of plants and animals.

Q10. In Fig.12.15, 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, carbon dioxide, oxygen, plants, animals, soil, roots, water table.

Ans:

Q11. Which of the following is not a forest product?

Ans: (iv) Kerosene

Q12. Which of the following statements is not correct?

Ans: (ii) Plants and animals in a forest are not dependent on one another. 

Q13. Micro-organisms act upon the dead plants to produce:

Ans: (iii) humus