Gujarat Board GSEB Textbook Solutions Class 7 Science Chapter 17 Forests: Our Lifeline Textbook Questions and Answers, Notes Pdf.
Gujarat Board Textbook Solutions Class 7 Science Chapter 17 Forests: Our Lifeline
Gujarat Board Class 7 Science Forests: Our Lifeline Textbook Questions and Answers
Question 1.
Explain how animals dwelling in the forest help it grow and regenerate.
Answer:
Animals help in growing and regenerating forests in many ways. Animals work as cleaning agents in the forest. Microorganisms work on dead bodies of plants and animals and degenerate them. Animals also help in pollination which helps in growing a number of plants. Herbivores help the carnivores to grow as they serve as food for them. Thus flora and fauna mutually grow in the forest.
Question 2.
Explain how forests prevent floods.
Answer:
Forests can absorb a lot of water. The roots of the trees absorb the water and prevent it from flowing away. Roots of trees also help in the percolation of water into the soil. This helps in preventing floods.
Question 3.
What are decomposers? Name any two of them. What do they do in the forest?
Answer:
Decomposers are the organisms that feed on the dead bodies of plants and animals. They clean the forests, decaying dead bodies and replenishing the nutrients back to the forest soil, e.g., beetles and grubs.
Question 4.
Explain the role of forest in maintaining the balance between oxygen and carbon dioxide in the atmosphere.
Answer:
Plants release oxygen in the atmosphere during the process of photosynthesis. This oxygen is inhaled by the animals for respiration. During respiration, they release carbon dioxide which is absorbed by plants. In this way, the oxygen and carbon dioxide cycle go on. Since forests contain a large number of plants, they help much in this cycle and maintain balance in nature.
Question 5.
Explain why there is no waste in the forest.
Answer:
There is no waste in the forest because decomposers convert all the dead bodies of the plants and animals into the humus which gets added to the soil. Thus, no waste remains.
Question 6.
List five products we get from forests.
Answer:
- We get medicines from forests.
- We get gum from forests.
- We get wood which is used for many purposes like making furniture, paper, etc.
- We get food for animals from forests
- We get sealing wax from forests.
Question 7.
Fill in the blank:
(a) The insects, butterflies, honeybees, and birds help flowering plants in ………….
(b) A forest is a purifier of ………… and …………
(c) Herbs form, the …………. layer in the forest.
(d) The decaying leaves and animal droppings in a forest enrich the ……….
Answer:
(a) pollination
(b) water, air
(c) lowest
(d) soil as humus.
Question 8.
Why should we worry about the conditions and issues related to forests far from us?
Answer:
We should be worried about deforestation as it would lead to floods, an increase in earth’s temperature, decreasing animals, habitats, and soil erosion. Damage to forests directly or indirectly affects the human habitat and environment so it must be a matter of concern among us.
Question 9.
Explain why there is a need of a variety of animals and plants in a forest.
Answer:
All plants and animals sustain the forest life and also CO2 – O2 cycle goes on due to animals and plants. Animals convert the dead and decaying matters into humus and increase the fertility of the soil, thus enhancing plant growth. All food chains and food webs need a variety of plants and animals.
Question 10.
In given fig. 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.
Answer:
Question 11.
Which of the following is not a forest product?
(i) Gum
(ii) Plywood
(iii) Sealing wax
(iv) Kerosene
Answer:
(iv) Kerosene
Question 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 water cycle.
(iv) Soil helps forests to grow and regenerate.
Answer:
(ii) Plants and animals in a forest are not dependent on one. another.
Question 13.
Micro-organisms act upon the dead plants to produce
(i) sand
(ii) mushrooms
(iii) humus
(iv) wood
Answer:
(iii) Humus
Extended Learning Activities And Projects
Question 1.
The Department of Environment is to decide whether some portion of a forest in your area could be cleared for a housing complex. Write a letter to the department explaining your point of view as a concerned citizen.
Answer:
The Director
Department of Environment
New Delhi
Subject – Deforestation in ………… area.
Sir,
I have come to know that your department has granted permission to clear the forest adjoining to my residential area. In this regard, I want to draw your kind attention towards the following points, i.e. after-effects of your decision:
(i) Due to the destruction of forests, wild animals will move to residential areas for food and shelter.
(ii) There will be climatic change due to an imbalance in oxygen and carbon dioxide. Deforestation will cause an increase in CO2 concentration in the atmosphere resulting in the greenhouse effect and an increase in temperature.
(iii) People living in a neighborhood who live in forest products will suffer.
(iv) Loss of trees and other vegetation may cause soil erosion.
(v) In absence of trees, the soil will not hold water which will cause a flood. Aforesaid are some of the points which may cause danger to our lives and environment due to deforestation. As a concerned citizen, I request to reconsider your decision in the public interest.
Thanking You
Yours faithfully
A concerned citizen
Question 2.
Visit a forest. Here is a list of points that would make your visit more fruitful.
(a) Make sure that you have permission to go into the forest.
(b) Make sure that you can find your way around. Get a map and go along with someone who is familiar with the area.
(c) Keep a record of the things you see and do. Observations make the visit interesting. Sketches and photographs are useful
(d) You may record bird calls.
(e) Collect different kinds of seeds or hard fruits like nuts.
(f ) Try to recognize various types of trees, shrubs, herbs, etc. Make lists of plants from different places in the forest and of different layers. You may not be able to name all the plants, but it is worth recording and seeing where they grow. Make a record of approximate heights of plants, crown shape, bark texture, leaf size, and flower color.
(g) Learn to recognize the animal’s droppings.
(h) Interview the forest officials and the people of surrounding villages and other visitors.
Answer:
Do it yourself.