NCERT Solutions for Class 7 Science Chapter 17 Forests Our Lifeline are provided here with simple step-by-step explanations. These solutions for Forests Our Lifeline are extremely popular among Class 7 students for Science Forests Our Lifeline Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the NCERT Book of Class 7 Science Chapter 17 are provided here for you for free. You will also love the ad-free experience on Meritnation’s NCERT Solutions. All NCERT Solutions for class Class 7 Science are prepared by experts and are 100% accurate.
Page No 89:
Question 1:
Which of the following serve as green lungs?
(a) Green pigment of the plants
(b) Forests
(c) Kitchen gardens
(d) Green house gases
Answer:
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.
Hence, the correct answer is option (b).
Page No 89:
Question 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
Answer:
The noise could disturb the birds and animals of the forest.
Hence, the correct answer is option (c).
Page No 89:
Question 3:
Which among the following forest animals is the smallest?
(a) Fox
(b) Boar
(c) Bison
(d) Porcupine
Answer:
Porcupine is the smallest forest animal among the given animals.
Hence, the correct answer is option (d).
Page No 89:
Question 4:
Which of the following has the strongest stem?
(a) A tree
(b) A creeper
(c) A climber
(d) A bush
Answer:
A tree has the strongest stem.
Hence, the correct answer is option (a).
Page No 89:
Question 5:
Which of the following is not prepared from the wood obtained from forest?
(a) Paper
(b) Thermocol
(c) Matchsticks
(d) Plywood
Answer:
Paper, matchsticks and plywood are obtained from the forest but thermocol is obtained from the synthetic fibre.
Hence, the correct answer is option (b).
Page No 90:
Question 6:
Which of the following is not the name of a tree?
(a) Teak
(b) Sal
(c) Porcupine
(d) Kachnar
Answer:
Porcupine is an animal while teak, sal and kachnar are trees.
Hence, the correct answer is option (d).
Page No 90:
Question 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
Answer:
Semal is a tree and Hornbill is an animal.
Hence, the correct answer is option (a).
Page No 90:
Question 8:
Which of the products is not obtained from a forest?
(a) Honey
(b) Catechu
(c) Gum
(d) Ginger
Answer:
Ginger is usually cultivated on farms and not found in the forest. Honey, gum and catechu are the products of a forest.
Hence, the correct answer is option (d).
Page No 90:
Question 9:
The branchy part of a tree above the stem is known as
(a) crown
(b) canopy
(c) sapling
(d) humus
Answer:
The branched part of a tree above the stem is called the crown of the tree.
Hence, the correct answer is option (a).
Page No 90:
Question 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 water table.
Answer:
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. On the other hand, if trees are not present, rain hits the ground directly and may flood the area around it.
Hence, the correct answer is option (b).
Page No 90:
Question 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?
Answer:
As trees absorb noise, noise pollution rarely occurs in a forest.
Page No 90:
Question 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.
(b) In a forest, trees form the uppermost layer, followed by herbs. The shrubs form the lowest layer of vegetation.
(c) The forest keeps on growing and changing and can regenerate.
(d) Forests protect the soil from erosion.
Answer:
(a) True
(b) False; In a forest, trees form the uppermost layer, followed by shrubs. The herbs form the lowest layer of vegetation.
(c) True
(d) True
Page No 91:
Question 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.
Answer:
The correct food chain will be-
grass→ insects→ frog → snake → eagle
Page No 91:
Question 14:
Give names of any four birds which you expect to see in a forest.
Answer:
Koel, kingfisher, jungle crow, myna, hornbill, etc. can be seen in a forest.
Page No 91:
Question 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 reason.
Answer:
As each forest has different climatic and environmental conditions, one would observe different types of plants and animals in different forests.
Page No 91:
Question 16:
“A bunch of seedlings were seen sprouting on a heap of animal dropping in a forest.” How do you think is the seedling benefited from the animal dung?
Answer:
The decaying animal dung provides the required nutrients for the seedlings to grow.
Page No 91:
Question 17:
Match Column I with Column II
| Column I | Column II |
| (a) Decomposers | (i) dead plant and animal tissues |
| (b) Canopy | (ii) habitats for wild life |
| (c) Porcupine | (iii) micro-organisms |
| (d) Humus | (iv) wild animal |
| (e) Forest | (v) branches of tall trees |
Answer:
| Column I | Column II |
| (a) Decomposers | (iii) micro-organisms |
| (b) Canopy | (v) branches of tall trees |
| (c) Porcupine | (iv) wild animal |
| (d) Humus | (i) dead plant and animal tissues |
| (e) Forest | (ii) habitats for wild life |
Page No 91:
Question 18:
Deforestation may lead to floods. Why?
Answer:
Deforestation is cutting down a forest, so if trees are not present, rain hits the ground directly and may flood the area around it. Heavy rain may also damage the soil. The roots of trees normally bind the soil together, but in their absence, the soil is washed away or eroded.
Page No 91:
Question 19:
Name any four useful products other than wood, which we get from forests.
Answer:
Catechu, sealing wax, medicine, timber, gum, and honey are few products we get from forest.
Page No 92:
Question 20:
In the given figure shows a part of a forest.
Write any three activities going on in the forest on the basis of this figure.
Answer:
The three activities going on in the forest on the basis of this figure-
(i) Photosynthesis taking place, through which plants give out oxygen.
(ii) Microorganisms decomposing dead and decaying material to release nutrients for plants.
(iii) Plants consuming carbon dioxide from the environment.
Page No 92:
Question 21:
People say that nothing goes waste in a forest. Can you explain, how?
Answer:
Forests are self-sustaining in function. The reasons why nothing goes waste in a forest are-
- Predators consume dead animals.
- Broken parts of trees are used as fuel by the people living near the forest.
- Microorganisms decompose the dead remnants of plants and animals.
Page No 92:
Question 22:
Give any four factors which are responsible for the destruction of forests.
Answer:
The factors which are responsible for the destruction of forests are-
- ​Cutting of trees for obtaining timber or other products
- Construction of roads through forest regions
- Construction of buildings near or inside forest regions
- Overgrazing by animals
Page No 92:
Question 23:
Draw a figure showing two animals, two birds and a few trees as a part of a forest.
Answer:
IMAGE
Page No 92:
Question 24:
All the needs of animals living in a forest are fulfilled. Justify this statement in a few sentences.
Answer:
The plants in the forest provide numerous necessities for animals. Animals need oxygen to breathe, which plants offer. Animals are directly or indirectly reliant on plants for their food. Carnivores rely on herbivores for food while herbivores get their nourishment directly from plants. Animals living in the wild can find shelter in trees. As a result, it is believed that a forest provides for all of the needs of its animal inhabitants.
Page No 92:
Question 25:
“Forests are our lifeline.” Write five sentences on this topic.
Answer:
Forests are very important for human beings, animals, etc.
- Forests are called the ‘green lungs of the world’. They purify the air and release oxygen by the process of photosynthesis.
- Forests provide us with timber, medicinal plants, gum, resins, etc. Forests are also important for wildlife as they provide them with food and shelter, and protect them from predators.
- When mountains lose their forest cover, rainwater rushes down very fast. This causes flooding of the plains. Forest cover prevents such floods.
- Forests allow water to seep into the soil, which in turn recharges groundwater. This prevents the problem of scarcity of water after the monsoon.
- Forests absorb dust and other pollutants. They absorb the noise coming from the nearby areas, thereby controlling noise pollution.
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