KSEEB Solutions for Class 7 Science Chapter 17 Forests: Our Lifeline

Students can Download Science Chapter 17 Forests: Our Lifeline Questions and Answers, Notes Pdf, KSEEB Solutions for Class 7 Science helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.

Karnataka State Syllabus Class 7 Science Chapter 17 Forests: Our Lifeline

Class 7 Science Water: A Precious Resource Textbook Exercise Questions and Answers

Question 1.
Explain how animals dwelling in the forest help it grow and regenerate,
Answer:
The animals in forests could be herbivores, carnivores, micro-organisms, etc. They play an important role in maintaining the food chain. The animals help in the following ways:

  • Animals help in seed dispersal and pollination.
  • The micro-organisms convert the dead plants and animals to humus. This humus helps in returning the nutrients back to the soil.
  • The decaying animal dung provides nutrients to the various seedlings to grow.

KSEEB Solutions for Class 7 Science Chapter 17 Forests: Our Lifeline

Question 2.
Explain how forests prevent floods.
Answer:
In the forest, the branches of the tall trees forms roof prevent rainwater directly hitting the ground. The rainwater falls on the branches and leaves come down slowly. Thus soil is able to absorb large amounts of water slowly. Humus also increases the absorbing power of the soil. Thus, forests prevent direct hitting of water to the ground and thus prevent floods.

Question 3.
What are decomposers? Name any two of them. What do they do in the forest?
Answer:
Decomposers are micro-organisms that convert the dead plants and animals to humus. Bacteria and fungi are the two types of decomposers. They help in the process of recycling of nutrients by decomposing various dead organisms such as plants and animals to form humus.

KSEEB Solutions for Class 7 Science Chapter 17 Forests: Our Lifeline

Question 4.
Explain the role of forest in maintaining the balance between oxygen and carbon dioxide in the atmosphere.
Answer:
Forests play an important role in maintaining the balance between oxygen and carbon dioxide in the atmosphere. Forest works like a self – sustaining system. Whatever is produced in the forest is utilized by different components of the forests. Animals during respiration take in oxygen and release carbon dioxide. Plants take in carbon dioxide and release oxygen through the process of photosynthesis. Even the waste is converted into beneficial substances in a forest. Due to this, there is no waste in the forest.

Question 5.
Explain why there is no waste in the forest.
Answer:
There is no waste in a forest because all waste generated is biodegradable on which microorganisms act and convert them into humus. This humus ensures that the nutrients are returned back to the soil.

KSEEB Solutions for Class 7 Science Chapter 17 Forests: Our Lifeline

Question 6.
List five products we get from forests.
Answer:
Five products we get from forests are:

  1. Wood
  2. Gum
  3. Medicinal plants
  4. Spices
  5. Oils.

Question 7.
Fill in the blanks:
(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) air, water
(c) lowest
(d) soil

KSEEB Solutions for Class 7 Science Chapter 17 Forests: Our Lifeline

Question 8.
Why should we worry about the conditions and issues related to forests far from us?
Answer:
There are various reasons for which we should be vigilant about matters related to forests.

  1. A decrease in forest area would lead to an increase in carbon dioxide in the air. This will increase the temperature of the earth’s atmosphere.
  2. Soil erosion would occur if there are no forests.
  3. Floods would be more frequent in absence of forests.
  4. Due to deforestation, many areas will slowly get converted into deserts. Therefore, we need to conserve our forest.

Question 9.
Explain why there is a need of a variety of animals and plants in a forest.
Answer:
A greater variety of plants and animals in the forests helps it to regenerate and grow. A greater variety of plants means more food and habitat for the herbivores. An increase in herbivores means more food for carnivores. Decomposers help to maintain the supply of nutrients to the soil and to the growing plants. This wide variety makes the forest a dynamic living entity.

KSEEB Solutions for Class 7 Science Chapter 17 Forests: Our Lifeline

Question 10.
In the given figure 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.
KSEEB Solutions for Class 7 Science Chapter 17 Forests Our Lifeline 1
Clouds, rain, atmosphere, carbon dioxide, oxygen, plants, animals, soil, roots, water table.
Answer:
KSEEB Solutions for Class 7 Science Chapter 17 Forests Our Lifeline 2

Question 11.
Which of the following is not a forest product?
(a) Gum
(b) Plywood
(c) Sealing wax
(d) Kerosene
Answer:
(d) Kerosene

Question 12.
Which of the following statements is not correct?
(a) Forests protect the soil from erosion.
(b) Plants and animals in a forest are not dependent on one another.
(c) Forests influence the climate and water cycle.
(d) Soil helps forests to grow and regenerate.
Answer:
(b) Plants and animals in a forest are not dependent on one another.

KSEEB Solutions for Class 7 Science Chapter 17 Forests: Our Lifeline

Question 13.
Micro-organisms act upon the dead plants to produce.
(a) sand
(b) mushrooms
(c) humus
(d) wood
Answer:
(c) humus

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