Forests: Our Lifeline Worksheet

Objective Type Questions

1. Fill in the blanks:
   Microorganisms which convert dead plants and animals to humus are called________.
   
   
2. Match the following:
   
   
   
3. Find the odd one out:
   Tulsi, Rubber, Eucalyptus, Neem
   
   
4. State whether the given statement is true or false:
   Vultures are decomposers.
   
   Multiple Choice Questions
   
   
5. Organisms which provide food to all animals in the forests, directly or indirectly, are known as
   (a) Autotrophs
   (b) Heterotrophs
   (c) Saprotrophs
   (d) Decomposers
   
   
6. Which of the following can be included in an ecosystem?
   (a) (i), (ii), (v) and (vi)
   (b) (iii) and (iv)
   (c) (i), (iii) and (iv)
   (d) All of these 
   
   
   
7. Smaller trees and tree saplings form the understorey layer of the forest. The understorey layer lies
   (a) below the herb layer
   (b) below the shrub layer
   (c) below the canopy
   (d) above the herb layer
   
   
8. Which of the following is NOT an advantage of forests?
   (a) Maintains water cycle in nature
   (b) Maintains a balance of CO₂ and O₂ in the atmosphere 
   (c) Makes soil infertile for crops
   (d) Prevents the occurrence of floods  
   
   
9. Which of the following will eat the dead bodies of other animals?
   (a) Bacteria
   (b) Jackal
   (c) Lion
   (d) Tiger
   
   Subjective Questions
   
   
10. How do forests act as purifiers of water and air?
    
    
11. Explain how various components of a forest are interdependent.
    
    
12. Nothing ever goes waste in a forest. Explain.
    
    
13. Draw four shapes of tree crown found in forests.
    
    
14. Forests are known to be green lungs. Give reason.
    
    
15. Arrange the following images in the correct order as per the food chain occurring in the forest habitat (Put appropriate arrows between the alphabet letters assigned to each image to show the correct order of the food chain)
    
    
    
16. How do forests help in reducing noise pollution?
    
    
17. State the difference between a creeper and a climber.
    
    Assertion-Reasoning Questions
    
    Below questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
    
    
    
18. Assertion: Plants are saprotrophs. 
    Reason: Plants are producers. 
    
    
19. Assertion: The forest is a dynamic living entity.
    Reason: The wide variety of plants and animals helps the forest to regenerate and grow.   
    
    Case-Based Questionsy
    
    
20.  
    
    The above picture shows the different layers of the forest. Answer the following questions based on it:
    (a) What is present in the uppermost layer of the forest? What is this layer of vegetation called?
    (b) Name the vegetation layer between the shrub layer and the forest floor in a forest.
    (c) What does layer 2 consist of? Name this layer.
    (d) What forms layer 3 of vegetation in a forest?  

Objective Type Questions
 

1. Fill in the blanks:
   Microorganisms which convert dead plants and animals to humus are called________.
   Solution: Microorganisms which convert dead plants and animals to humus are called decomposers.
   
   
2. Match the following:
   
   Solution:
   
   
   
3. Find the odd one out:
   Tulsi, Rubber, Eucalyptus, Neem
   Solution: Rubber
   Neem, Tulsi and Eucalyptus are medicinal plants that help in curing diseases, while rubber plant is used to manufacture rubber in the rubber industry.
   
4. State whether the given statement is true or false:
   Vultures are decomposers.
   Solution: False.
   Vultures, crows, jackals and hyenas are scavengers which eat up the dead bodies of animals and help in keeping the forest clean. However, they do not break down the dead animals to simple substances like humus which can be reused by the plants. Hence, vultures cannot be called decomposers.
   
   Multiple Choice Questions
   
   
5. Organisms which provide food to all animals in the forests, directly or indirectly, are known as
   (a) Autotrophs
   (b) Heterotrophs
   (c) Saprotrophs
   (d) Decomposers
   Correct option: (a) Autotrophs
   Solution: Organisms which provide food to all animals in the forests, directly or indirectly, are known as autotrophs or producers, e.g., plants.
   
   
6. Which of the following can be included in an ecosystem?
   (a) (i), (ii), (v) and (vi)
   (b) (iii) and (iv)
   (c) (i), (iii) and (iv)
   (d) All of these 
   
   Correct option: (d) All of these
   Solution: An ecosystem is a self-sufficient unit of living things and their non–living environment. It consists of living things such as plants, animals and decomposers, and non–living things such as soil, water, sunlight and air.
   
   
7. Smaller trees and tree saplings form the understorey layer of the forest. The understorey layer lies
   (a) below the herb layer
   (b) below the shrub layer
   (c) below the canopy
   (d) above the herb layer
   Correct option: (c) below the canopy
   Solution: The understorey layer of the forest lies just below the canopy and above the shrub layer.
   
   
   
8. Which of the following is NOT an advantage of forests?
   (a) Maintains water cycle in nature
   (b) Maintains a balance of CO₂ and O₂ in the atmosphere 
   (c) Makes soil infertile for crops
   (d) Prevents the occurrence of floods 
   Correct option: (c) Make soils infertile for crops
   Solution: Forests prevent soil erosion by preserving the fertile top layer of soil. Cutting down of forests leads to soil erosion, removing the fertile top layer of the soil and making the land unsuitable for growing crops.
   
   
9. Which of the following will eat the dead bodies of other animals?
   (a) Bacteria
   (b) Jackal
   (c) Lion
   (d) Tiger
   Correct option: (b) Jackal
   Solution: Jackal is a scavenger that feeds on the dead bodies of other animals.
   
   Subjective Questions
   
   
10. How do forests act as purifiers of water and air?
    Solution: Trees absorb the dirty water from the soil through their roots and make pure water available in the form of rain through the water cycle. Trees act as green filters by releasing oxygen as a product of photosynthesis, thus purifying air by increasing oxygen in the atmosphere. They also help in removing harmful particles and pollutants. In this way, forests act as purifiers of water and air.
    
    
11. Explain how various components of a forest are interdependent.
    Solution: 
    (i) A large and diverse variety of flora and fauna live together and maintain the ecological balance in a forest. Plants and animals are dependent on each other for oxygen-carbon dioxide balance, food and other factors.
    (ii) The biotic and abiotic factors of the forest ecosystem are interdependent and essential.
    (iii) Green plants produce food. All animals, including herbivores and carnivores depend directly or indirectly on plants for food. Organisms which feed on plants are consumed by other organisms. For example, grass is eaten by insects which in turn are eaten by a frog. The frog is consumed by snakes. This forms a food chain.
    (iv) There are various food chains in the forests. All food chains are interlinked. If any one food chain is disturbed, it affects the other food chains.
    (v) In this way, various components of a forest are interdependent.
    
12. Nothing ever goes waste in a forest. Explain.
    Solution:
    (i) The dead plants, dry leaves, remains of dead plants and animals and animal tissues are converted into a dark-coloured substance called humus. This humus is rich in nutrients. The humus ensures that it gets readily mixed with the soil so that it could be absorbed by the roots of the plants.
    (ii) The dead animals are eaten by the scavengers like vultures, crows, jackal, hyenas and some insects like ants and termites
    (iii) Broken branches of trees are used as fuel by the people living in the vicinity of the forest.
    (iv) In this way, each and every component of the forest is utilised in some or the other way. Hence, nothing goes to waste in a forest. 
    
    
13. Draw four shapes of tree crown found in forests.
    Solution: Some tree crowns seen in forests are as follows:
    
    
    
14. Forests are known to be green lungs. Give reason.
    Solution: Plants release oxygen through the process of photosynthesis which is used by the animals for respiration. They also maintain the balance of oxygen and carbon dioxide in the atmosphere. That is why forests are called green lungs.
    
    
15. Arrange the following images in the correct order as per the food chain occurring in the forest habitat (Put appropriate arrows between the alphabet letters assigned to each image to show the correct order of the food chain)
    
    Solution: The correct order of the food chain is: 
    (d) → (a) → (c) → (b) → (e)
    Producers (grass) → herbivore(grasshopper) → carnivore (frog) → large carnivore (snake) →  Top carnivore (Eagle)
    
    
16. How do forests help in reducing noise pollution?
    Solution: Forests absorb the noise of the activities occurring in the nearby areas like the sound of the vehicles from the nearby highway and thus help in reducing noise pollution.
    
    
17. State the difference between a creeper and a climber.
    Solution: A creeper tends to creep along the soil surface and spread over a long distance. A climber has a weak stem and hence, tends to climb up to some support in order to reach the sunlight.
    
    Assertion-Reasoning Questions
    
    Below questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
    
    
    
18. Assertion: Plants are saprotrophs. 
    Reason: Plants are producers.
    Correct option: (d) A is false, but R is true. 
    Solution: Plants are autotrophs because they produce their own food by the process of photosynthesis. Thus, they are also called producers. Saprotrophs are decomposer organisms which feed on dead plants and animals. Thus, plants are not saprotrophs.  Thus, the given assertion is false but the reason is true.
    
    
19. Assertion: The forest is a dynamic living entity.
    Reason: The wide variety of plants and animals helps the forest to regenerate and grow.
    Correct option: (a) Both A and R are true, and R is the correct explanation of A. 
    Solution: The forest harbours a great variety of plants and this provides greater opportunities for food and habitat for the herbivores. 
    A larger number of herbivores provides increased availability of food for a variety of carnivores. Decomposers help in maintaining a supply of nutrients to the growing plants in the forest. Thus, the forest is full of life and vitality and hence, is considered as a dynamic living entity. Thus, both assertion and reason are true and reason is the correct explanation of assertion.
    
    
    Case-Based Questionsy
    
    
20.  
    
    The above picture shows the different layers of the forest. Answer the following questions based on it:
    (a) What is present in the uppermost layer of the forest? What is this layer of vegetation called?
    (b) Name the vegetation layer between the shrub layer and the forest floor in a forest.
    (c) What does layer 2 consist of? Name this layer.
    (d) What forms layer 3 of vegetation in a forest? 
    Solution:
    (a) The uppermost branches and leaves of tall trees are present in the highest layer of the forest. This layer is called a canopy. 
    (b) Herb layer 
    (c) Layer 2 mainly consists of smaller trees and tree saplings. This layer is called the understorey. 
    (d) Layer 3 is a shrub layer and mainly consists of mature shrubs and bushes.