Forests Our Lifeline is Chapter 17 taken from the JKBOSE textbook of Science for students of Class 7th. In the previous post, I provided you with Questions and Answers for Chapter 16 Water. This post is about Forests Our Lifeline Class 7 Question Answers. Before we proceed to Question Answers, you need to have basic information about the chapter. So here is a brief overview of the chapter:
Forests Our Lifeline Class 7 Question Answers
Overview of Chapter
- COMPONENTS OF A FOREST.
- STRUCTURE OF A FOREST.
- IMPORTANCE OF FORESTS.
- CONSERVATION OF FORESTS.
COMPONENTS OF A FOREST: There are two components of a forest. These are:
- Non-Living Component: The non-living component of a forest includes soil, water and air. The non-living component of a forest is necessary for the growth of plants in a forest.
- Living Component: The living components of a forest includes plants, animals, decomposers and scavengers.
- Plants: A forest has many types of green plants in it. They prepare their own food through the process of photosynthesis so they are called producers (autotrophs). They are a source of food for all the animals living in a forest directly or indirectly.
- Animals: There are several types of animals living in a forest. They are called consumers (heterotrophs) because they depend on plants or other animals for their food. The animals living in a forest may be herbivores or carnivores.
- Decomposers: These include microorganisms like bacteria and fungi. They feed on the dead bodies of plants and animals. They are termed saprotrophs. They are called decomposers because they decompose (break down) dead plants and animals into simpler substances.
- Scavengers: The animals which feed on the dead bodies of other animals are termed scavengers. These include vultures, crows, jackals, and some insects like ants, beetle, termites, woodlice etc. They are called cleaning agents of our environment.
STRUCTURE OF A FOREST: There are different horizontal layers of plants in a forest which collectively form the structure of a forest. Scientists have divided forests into five horizontal layers. These are a) Canopy b) Understorey c) Shrub Layer d) Herb Layer e) Forest Floor.
- Canopy: The uppermost branches and leaves of tall trees which act like a roof over the forest ground is called the canopy. It is the highest layer of vegetation in a forest. The branchy part of a tree above the stem is known as the crown of the tree.
- Understorey: The layer of vegetation which is just below the canopy is termed understorey. It consists of smaller trees and tree saplings.
- Shrub Layer: The layer of vegetation which is just below the understorey is called as shrub layer. It consists mainly of mature shrubs and bushes. The shrub layer has vegetation which is between 1-2 metres of height from the forest floor.
- Forest Floor: The ground surface of the forest is called the forest floor. The forest floor has many kinds of plants like mosses, liverworts and lichens. Forest floor is covered with dead and decaying plant matter and animal waste.
IMPORTANCE OF FORESTS: Forests provide us variety of products. They also purify air and water quality and soil maintenance and climate. They also balance the level of CO2 and O2 in the air. Due to these reasons, forests are called our lifeline. Some important uses of forests are as under:
- Forests provide many useful products.
- They maintain the balance between oxygen and carbon Dioxide.
- Forests maintain the water cycle.
- They prevent the occurrence of floods.
- Forests provide a habitat for wildlife.
- They can regenerate on their own.
CONSERVATION OF FORESTS: Forests are extremely important for us, and other living organisms on earth and the balance of the environment. They must be conserved. The following steps can be taken to conserve forests.
- Government should ban the excessive cutting of trees.
- More trees should be planted in place of cut-down trees.
- The paper should be recycled and used again.
Chapter 17 Forests Our Lifeline Questions
1. Explain how animals dwelling in the forest help it grow and regenerate.
Ans. There is a variety of animals living in a forest. They are herbivores, carnivores and microorganisms etc. The dwelling of these animals in the forest helps them grow and regenerate in the following ways:
a) Microorganisms convert dead plants and animals into simpler substances which are absorbed in the soil and are used by plants for their growth.
b) The decaying animal dung provides nutrients to the growing plants.
c) Animals are also responsible for the dispersal of seeds of certain plants.
2. Explain how forests prevent floods.
Ans. Forests absorb the rainwater and allow it to seep into the soil. Forests bind the particles of soil together and do not allow it to get carried away by rainwater. They also reduce the runoff water. If forests are not present on earth the rainwater would hit the ground directly resulting in floods.
3. What are decomposers? Name any two of them. What do they do in the forest?
Ans. They are microorganisms which convert dead plants and animals into humus. Bacteria and Fungi are the two most common decomposers.
Microorganisms help in the process of recycling nutrients and clearing forests. They convert dead plants and animals into simple usable nutrients which are absorbed in the soil and are used for the growth of plants.
4. Explain the role of forests in maintaining the balance between oxygen and carbon dioxide in the atmosphere.
Ans. Human beings and other animals use oxygen and release carbon dioxide into the atmosphere during respiration. The burning of fuel in homes, transport and factories also adds carbon dioxide into the atmosphere. Carbon dioxide is used by plants for the process of photosynthesis while oxygen is released during this process. In this way, plants maintain the balance of oxygen and carbon dioxide in the atmosphere.
5. Explain why there is no waste in a forest.
Ans. There is no waste in the forests because decomposers act on dead plants and animals and convert them into humus which adds to the soil and provides nutrients to the plants.
6. List five products we get from forests?
Ans. The five products that se get from forests are:
- Fill in the blank:
(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.
- Why should we worry about the conditions and issues related to forests far from us?
Ans. We should worry about the conditions and issues related to forests far from us because of the following reasons:
1) Forest purifies air and water.
2) They play an important role in the water cycle.
3) If the forest is decreased, it will increase the level of carbon dioxide in the atmosphere which will increase the temperature of the earth.
4) Forests provide us with food and they are also habitats for animals.
5) Forests prevent the occurrence of floods and also reduce soil erosion.
- Explain why there is a need for a variety of animals and plants in a forest.
Ans. There is a need for a variety of animals and plants in a forest because it helps the forests to regenerate and grow. It also maintains a balance between carbon dioxide and oxygen in the atmosphere. The greater variety of plants means more food and habitat opportunities for herbivores which increases their number in a forest. An increase in the number of herbivores means food for carnivores. The variety of plants and animals in a forest is important for ecological balance.
- 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, carbon dioxide, oxygen, plants, animals, soil, roots, and water table.
- Which of the following is not a forest product?
(iii) Sealing wax
Ans. (iv) Kerosene.
- 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.
Ans. (ii) Plants and animals in a forest are not dependent on one another.
- Micro-organisms act upon the dead plants to produce
Ans. (iii) humus
- Tick mark the correct choice.
- Micro-organism which converts dead plants, animals into humus are known as: –
Ans. (a) Decomposers
- Which of the following is not a forest product?
Ans. (d) Gasoline
- Deforestation results in
(a) Increase in rainfall
(b) Global warming
(c) Increase in water level
(d) Conservation of soil
Ans. (b) Global warming
- 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
That’s all about Forests Our Lifeline Class 7 Question Answers. Hope it has helped. Do share your views about this post in the comment section below.