Topic outline

    • Forests: Our Lifeline

      Q1. Fill in the blanks.

                                i.        The insects, butterflies, honeybees and birds help flowering plants in pollination.

                               ii.        A forest is a purifier of air and water.

                              iii.        Herbs form the lowest layer in the forest.

                              iv.        The decaying leaves and animal droppings in a forest enrich the soil.


      Q2. True/False

                                i.        Forests protect the soil from erosion. True

                               ii.        Plants and animals in a forest are not dependent on one another. False

                              iii.        Forests influence the climate and water cycle. True

                              iv.        Soil helps forests to grow and regenerate. True


      Q3. What happens if an animal dies in the forest?

      Ans. Dead animals become food for vultures, crows, jackals and insects.

      Q4. Which of the following is not a forest product?

            (i) Gum (ii) Plywood (iii) Sealing wax (iv) Kerosene

      Ans. Kerosene


      Q5. Micro-organisms act upon the dead plants to produce

            (i) sand (ii) mushrooms (iii) humus (iv) wood

      Ans. Humus


      Q6. What is known as the crown of the tree?

      Ans. Branchy part of a tree above the stem is known as the crown of the tree.


      Q7. What is canopy?

      Ans. Branches of the tall trees look like a roof over the other plants in the forest. This is called a canopy.


      Q8. List five products we get from forests.

      Ans. Gum, oils, spices, fodder for animals and medicinal plants are some of the products which we get from the forest.

      Q9. What are known as understoreys in forest?

      Ans. Trees have crowns of different types and sizes. These create different horizontal layers in the forest. These are known as understoreys.


      Q10. What is the effect of deforestation on soil?

      Ans. Roots of trees normally bind the soil together, but in their absence the soil is washed away or eroded.


      Q11. In which layer of the soil would you find humus? What is its importance to the soil?

      Ans. Humus is found in the top, organic layer of soil. Humus provides many useful nutrients to the soil.


      Q12. Why does the forest floor seem to be dark-coloured?

      Ans. The forest floor seem to be dark coloured as it is covered with a layer of dead and decaying leaves, fruits, seeds, twigs and small herbs. The decaying matter was moist and warm.


      Q13. Who would have planted trees in forest?

      Ans. In nature trees produce enough seeds. The forest floor provides favourable conditions for them to germinate and develop into seedlings and saplings. Some grow up into trees.

      Q14. Why even after heavy rainfall water do not stagnate in the forest?

      Ans. Forest acts as a natural absorber of rainwater and allows it to seep. It helps maintain the water table throughout the year. Forests not only help in controlling floods but also help maintain the flow of water in the streams so that we get a steady supply of water.


      Q15. Why forests are called green lungs?

      Ans. Plants release oxygen through the process of photosynthesis. The plants help to provide oxygen for animal respiration. They also maintain the balance of oxygen and carbon dioxide in the atmosphere. That is why forests are called lungs.


      Q16. Why raindrops do not hit the forest floor directly?

      Ans. The uppermost layer of the forest canopy intercept the flow of raindrops and most of the water come down through the branches and the stems of the trees. From the leaves it drips slowly over branches of the shrubs and herbs. Thus, raindrops do not hit the forest floor directly.


      Q17. Why are forests disappearing?

      Ans.  Forests are disappearing due to:

                                i.        Construction of roads, buildings, industrial development and increasing demand of wood.

                               ii.        Overgrazing of animals and indiscriminate felling of trees for agricultural land.


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