1. Choose the correct option.
a. Which is the lowest layer of the forest?
i. Emergent
ii. Forest floor
iii. Canopy
iv. Understorey
Answer: ii. Forest floor
b. Which of these animals is an omnivore?
i. Bear
ii. Tiger
iii. Fox
iv. Hawk
Answer: i. Bear
c. The components of a food chain – grass, eagle, insects, frog, and snake can be represented in a proper sequence by:
i. Grass → insects → snake → eagle → frog
ii. Grass → frog → snake → eagle → insects
iii. Grass → insects → frog → snake → eagle
iv. Grass → snake → eagle → insects → frog
Answer: iii. Grass → insects → frog → snake → eagle
d. Which one of the following statements is incorrect about forests?
i. Forests maintain the balance of gases in the atmosphere.
ii. Forests decrease the overall temperature.
iii. Forests help in the removal of topsoil.
iv. Forests replenish groundwater.
Answer: iii. Forests help in the removal of topsoil.
2. Assertion–Reasoning questions
(i)
Assertion (A): Forests are renewable natural resources.
Reason (R): Trees that are cut can grow back to replenish nature.
a. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
b. Both Assertion (A) and Reason (R) are true, and Reason (R) is not the correct explanation of the Assertion (A).
c. Assertion (A) is true, but Reason (R) is false.
d. Assertion (A) is false, but Reason (R) is true.
Answer: a. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
(ii)
Assertion (A): Bacteria and fungi help in recycling nutrients back to the soil.
Reason (R): They are scavengers.
a. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
b. Both Assertion (A) and Reason (R) are true, and Reason (R) is not the correct explanation of the Assertion (A).
c. Assertion (A) is true, but Reason (R) is false.
d. Assertion (A) is false, but Reason (R) is true.
Answer: c. Assertion (A) is true, but Reason (R) is false.
3. Answer the following questions in one sentence.
a. How can forests regenerate with the help of animals?
Answer: Animals help in forest regeneration by dispersing seeds through their droppings.
b. What is an ecosystem?
Answer: An ecosystem is a system formed by the interaction between living and non-living things in an environment.
c. What is a food chain?
Answer: A food chain shows how energy passes from one organism to another in an environment.
d. What is afforestation?
Answer: Afforestation is the process of planting trees in an area where there were no forests before.
4. Answer the following in 2-3 sentences.
a. How do forests help in controlling floods?
Answer: Forests control floods by acting as a natural sponge. The roots of trees hold the soil together, reducing soil erosion, while the forest floor absorbs rainwater and allows it to seep into the ground, which recharges groundwater and reduces surface runoff.
b. Why forests are called ‘green lungs’?
Answer: Forests are called ‘green lungs’ because they absorb carbon dioxide from the atmosphere during photosynthesis and release life-supporting oxygen. In this way, they purify the air, much like our lungs do for our bodies.
c. Give any four regions of India where mountain forests are found.
Answer: In India, mountain forests are found in regions like the Himalayas, the Vindhyas, the Nilgiri Hills, and the Western Ghats.
d. List the animals found in mangrove forests.
Answer: Animals commonly found in mangrove forests include the Royal Bengal Tiger, crocodiles, turtles, and various species of snakes and birds.
5. Answer the following questions in 3-4 sentences.
a. What is the main characteristic of a tropical deciduous forest?
Answer: The main characteristic of tropical deciduous forests is that they are composed of trees that shed their leaves during a specific season, typically the dry summer season, to conserve water. These forests are also known as monsoon forests and are found in regions with a distinct wet and dry climate.
b. List the effects of deforestation.
Answer: The effects of deforestation include:
- Increased Global Warming: It raises the level of carbon dioxide in the atmosphere.
- Soil Erosion: The loss of tree roots leads to the topsoil being washed away.
- Loss of Habitat: It destroys the natural homes of many plants and animals, threatening biodiversity.
- Disturbance in the Water Cycle: It reduces the recharge of groundwater and can lead to drier climates.
c. State any four ways to conserve forests.
Answer: Four ways to conserve forests are:
1. Afforestation: Planting new trees to create new forests.
2. Preventing Forest Fires: Implementing measures to control and quickly put out forest fires.
3. Controlled Grazing: Managing the grazing of domestic animals in forest areas.
4. Strict Laws: Enforcing laws and creating protected areas like wildlife sanctuaries and national parks.