NCERT Exemplar for Class 7 Science Solutions Chapter 17 Forests : Our Lifeline

Multiple Choice Questions

1. Which of the following serve as green lungs?

(a) Green pigment of the plants

(b) Forests

(c) Kitchen gardens

(d) Greenhouse gases

Ans: The correct answer is option (b), Forests. Plants and trees work as green lungs because they give out oxygen and take carbon dioxide from us.

2. Boojho visited a forest near his town with his classmates and his teacher. As they were entering the forest, their class teacher told them not to make noise in the forest as noise could disturb the

(a) Birds

(b) Animals

(c) Both birds and animals

(d) Plants

Ans: The correct answer is option (c), Both birds and animals.

3. Which among the following forest animals is the smallest?

(a) Fox

(b) Boar

(c) Bison

(d) Porcupine

Ans: The correct answer is option (d), Porcupine.

4. Which of the following has the strongest stem?

(a) A tree

(b) A creeper

(c) A climber

(d) A bush

Ans: The correct answer is option (a), A tree.

5. Which of the following is not prepared from the wood obtained from forest?

(a) Paper

(b) Thermocol

(c) Matchsticks

(d) Plywood

Ans: The correct answer is option (b), Thermocol

6. Which of the following is not the name of a tree?

(a) Teak

(b) Sal

(c) Porcupine

(d) Kachnar

Ans: The correct answer is option (c), Porcupine. Porcupines are wild animals, whereas Teak, Sal, and Kachnar are all trees.

7. Pick the option which gives the names of a tree and an animal, respectively from the following.

(a) Semal, hornbill

(b) Sal, khair

(c) Chinkara, blue bull

(d) Neem, Palash

Ans:  The correct answer is option, (a) Semal, hornbill.

8. Which of the products is not obtained from a forest?

(a) Honey

(b) Catechu

(c) Gum

(d) Ginger

Ans: The correct answer is option (d), Ginger.

9. The branchy part of a tree above the stem is known as

(a) Crown

(b) Canopy

(c) Sapling

(d) Humus

Ans: The correct answer is an option (a), Crown. The crown is the topmost part of the tree, under which all other parts emerge.

10. Forests are not responsible for

(a) Providing medicinal plants

(b) Maintaining the flow of water into the streams

(c) Creating flood conditions

(d) Absorbing rainwater and maintaining the water table

Ans: The correct answer is an option (c), Creating flood conditions.

Very Short Answer Questions

11. Paheli while moving in a forest observed that there was no noise pollution, though lots of heavy vehicles were passing from the nearby highway. Explain why?

Ans:  Because trees absorb sound, they help to reduce noise pollution.

12. State whether the following statements are true or false. If false, give the correct statement.

(a) Forests influence climate, water cycle and air quality.

Ans: The given statement is true.

(b) In a forest, trees form the uppermost layer, followed by herbs. The shrubs form the lowest layer of vegetation.

Ans: The given statement is False. In forests, the uppermost layer is formed by trees, the second layer is formed by shrubs and the lowest layer is formed by herbs of the vegetation

(c) The forest keeps on growing and changing and can regenerate.

Ans: The given statement is true.

(d) Forests protect the soil from erosion.

Ans: The given statement is true.

13. Paheli wrote a food chain in the following way:

Frog → Eagle → Insects → Grass → Snake

The chain is not in the correct order. Help her to write the food chain correctly.

Ans: The correct food chain will be: Grass → Insects → Frog → Snake → Eagle.

Short Answer Questions

14. Give names of any four birds which you expect to see in a forest.

Ans: Four birds that could be seen in the forest are: Kingfisher, hornbill, Jungle crow, Myna.

15. Two friends shared their experiences of their vacation trip to two different forests. Do you think they would have seen the same type of plants and animals during their respective trips? Give a reason.

Ans: Every forest has different types of climatic conditions because of which there are various plants and animals in every forest. Two different forests would not have the same type of plants and animals because of their different climatic conditions.

16. “A bunch of seedlings were seen sprouting on a heap of animal dropping in a forest.” How do you think the seedling benefited from the animal dung?

Ans: The seedlings are nourished with all the vital elements needed for plant growth by the animal dung as they can be easily absorbed due to presence of moisture. Animal dung is high in nitrogen and other nutrients.

17. Match Column I with Column II

Ans:  The correct match is

18. Deforestation may lead to floods. Why?

Ans:  Deforestation is the cutting of trees on a large scale. Deforestation leads to floods as, during rainfall, the canopies of the trees prevent the water from directly falling on the ground and making it stagnant. Because water moves slowly, the soil has an easier time absorbing it. In the absence of trees, the water rushes down the soil and erodes it without being absorbed.

19. Name any four useful products other than wood, which we get from forests.

Ans: Forests provide not only wood, but also latex, oils, spices, turpentine, and other commodities.

Long Answer Questions

20. Figure shows a part of a forest.

Write any three activities going on in the forest on the basis of this figure.

Ans:  Any of the following three activities taking place in the forest are-

i. Trees and plants are consuming carbon dioxide from the surroundings.

ii. Trees and plants are also giving out oxygen.

iii. Fallen leaves and branches are getting decomposed slowly by the microorganisms.

21. People say that nothing goes to waste in a forest. Can you explain, how?

Ans:  The reasons why nothing goes waste in a forest is because

i. Predators such as vultures, jackals, and other woodland carnivores consume dead animals.

ii. Remnants of dead animals and plants get decomposed to form humus by the microorganisms present in the soil.

iii. Hunters and those who live there use the broken branches of the trees.

22. Give any four factors which are responsible for the destruction of forests.

Ans: Forests are being destroyed because of the following reasons

i. Agriculture

ii. Industrialisation and area needed for constructing buildings.

iii. Growing demand for wood for furniture and household materials.

iv. Construction of broader roads.

23. Draw a figure showing two animals, two birds and a few trees as a part of a forest.

24. All the needs of animals living in a forest are fulfilled. Justify this statement in a few sentences.

Ans: Because of the following factors, animals in the forest do not suffer-

i. Plants consume carbon dioxide and give out oxygen to the animals for respiration.

ii. Plant eating animals (herbivores) depend on plants and trees and the animals eating flesh (carnivores) eat some herbivores animals.

iii. Big trees or trees are a shelter to many forest animals like monkeys, snakes, birds, etc.

25. “Forests are our lifeline.” Write five sentences on this topic.

Ans: Forests are our lifeline for the following reasons-

i. Trees are responsible for the health of the rest of the natural environment.

ii. They give us oxygen for respiration.

iii. Trees absorb sound and hence reduce noise pollution.

iv. Forests help to reduce floods in neighboring areas by increasing the soil's water holding capacity.

v. Trees provide us with food (fruits and vegetables), while medicinal plants provide some treatment.

vi. Forests provide a safe haven for wildlife.

Forests- Our Lifeline, Class 7 Science Chapter 17

Forests have always been an important resource to humanity, from early ages, this chapter will dive into that. The chapter emphasizes the need for forests and how human activities are destroying this precious resource. These lessons are essential for children to understand the value of resources and learn how to protect them.