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Q1. Forests are useful to us in many ways. However, man has also faced some undesirable consequences due to forests. Which of the following is one of them?

• Prevention of floods
• Prevention of soil erosion
• Maintenance of water table
• Forest fires

Solution

Forest fires are the most common hazards in the forests. They pose a threat not only to the forest wealth but also to the entire flora and fauna disturbing the biodiversity and the ecology and environment of a region. 

Q2. What prevents sunlight from entering forests?

• Covering of leaves
• Covering of branches
• Covering of stems
• Covering of flowers

Solution

The thick covering of leaves hardly allows sunlight to enter forests, thus making thick forests very dark.

Q3. A large area of land on which trees and other plants grow naturally is termed

• Forest
• Biosphere
• Zoo
• National park

Solution

A forest is a large area where natural vegetation and wildlife are found.

Q4. In a food chain, energy is transferred from green plants to 

• Herbivores
• Carnivores
• Omnivores
• Decomposers

Solution

In a food chain, energy is transferred from green plants to herbivores. Green plants are producers which prepare their food by utilising solar energy, and herbivores are plant eaters only.

Q5. Plants release excessive water into the atmosphere by the process of 

• Translocation
• Transpiration
• Respiration
• Reproduction

Solution

Very little water is used by plants for photosynthesis; the remaining water is released in the atmosphere through stomata present in the leaves by transpiration.

Q6. Which oil is required for the manufacture of rubber?

• Turpentine
• Coconut
• Mustard
• Sunflower

Solution

Rubber is manufactured by processing latex and using turpentine oil.

Q7. A technique used to grow plants in nutrient solutions rather than in the soil is called

• Hydroponics
• Vegetative propagation
• Micropropagation
• Tissue culture

Solution

Hydroponics is a technique which enables plants to grow in nutrient solutions rather than in soil.

Q8. Paper is obtained from

• Latex
• Resin
• Wood pulp
• Gum

Solution

Wood pulp is processed to make paper.

Q9. Which of the following are the possible causes of forest fire? (A) Carelessness of human beings (B) Lightning during a storm (C) Friction by dry stems and branches of trees

• (A) and (B)
• (B) and (C)
• (A) and (C)
• (A), (B) and (C)

Solution

Huge forest areas are destroyed by fires every year because of people’s carelessness, lightning or by friction between dry stems and dry branches of leaves.

Q10. What do we call the branches of tall trees which look like a roof over other plants?

• Crown
• Canopy
• Cap
• Understorey

Solution

When trees of different sizes are grown in a forest, the branches of tall trees look like a roof over short plants. This is called a canopy.

Q11. Which plants form the lowest layer of the understorey?

• Herbs
• Shrubs
• Trees
• Climbers

Solution

Herbs are the shortest among all plants, so they form the lowest layer of the understorey.

Q12. The layer of vegetation in a forest which grows under the shade of the canopy is called

• Crown
• Canopy
• Understorey
• Forest floor

Solution

The layer of vegetation in a forest which grows under the shade of the canopy is called understorey. There are different horizontal layers in the understorey depending on the size of the plants.

Q13. Which part of the plant binds soil particles to prevent soil erosion?

• Leaves
• Stem
• Roots
• Flowers

Solution

Roots bind soil particles and do not let the soil to wash away with water or wind.

Q14. After primary consumers, what is the next trophic level in a food chain?

• Producers
• Carnivores
• Top carnivores
• Decomposers

Solution

After primary consumers, the next trophic level in a food chain comprises secondary consumers or carnivores which eat other animals.

Q15. Forests are called green

• Lungs
• Liver
• Heart
• Pancreas

Solution

Forests are called green lungs because they provide oxygen for breathing and help maintain the ratio of oxygen to carbon dioxide in the atmosphere.

Q16. A network of several food chains connecting each other is called a

• Food web
• Food pyramid
• Food cycle
• Trophic level

Solution

Food web is a network of a large number of food chains existing in an ecosystem which shows the linkages among the various species.

Q17. Which of the following constitutes a food chain?

• Grass → Wheat → Mango
• Grass → Goat → Humans
• Goat → Cow → Elephant
• Grass → Fish → Goat

Solution

This food chain tells us that grass is eaten by goat, and the goat is then eaten by humans. In this food chain, grass is the producer, goat is a herbivore and human beings are carnivores.

Q18. Which of the following is not obtained from plants?

• Medicines
• Paper
• Spices
• Honey

Solution

Plants provide us with a variety of products such as paper, timber, medicines and spices which we use in daily life. Honey is obtained from honeybees.

Q19. Which of the following is not a medicinal plant?

• Neem
• Tulsi
• Foxglove
• Tobacco

Solution

Neem, tulsi and foxglove are medicinal plants which help to cure diseases. Tobacco is not a medicinal plant. 

Q20. Which of the following is released during the decay of organic matter?

• Light
• Heat
• Moisture
• Oxygen

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