Class 10 Science: Food Chains and Webs & How Our Activities Affect The Environment — Practice Questions with Answers

Identify which of the following groups contains only biodegradable items.

1. Grass, flowers and leather
2. Grass, wood and plastic
3. Fruit-peels, cake and lime-juice
4. Cake, wood and grass

From the given options, which one represents a valid food-chain?

1. Grass, wheat and mango
2. Grass, goat and human
3. Goat, cow and human
4. Grass, fish and goat

From the given lists, identify which groups of organisms do not form a valid food chain: (i) Wolf, rabbit, grass, lion (ii) Plankton, man, grasshopper, fish (iii) Hawk, grass, snake, grasshopper, frog (iv) Grass, snake, wolf, tiger

1. (i) and (iv)
2. (i) and (iii)
3. (ii) and (iii)
4. (ii) and (iv)

Two statements are given, one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the codes (a), (b), (c) and (d) as given below. Assertion (A): The amount of ozone in the atmosphere began to drop sharply in the 1980s. Reason (R): The oxygen atoms combine with molecular oxygen to form ozone.

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.

What is the approximate percentage of solar energy that is NOT converted into chemical energy by green plants in a land-based ecosystem?

1. 1%
2. 10%
3. 90%
4. 99%

From the options provided, choose the one that consists entirely of non-biodegradable substances.

1. Leather, Glass, Plastic
2. Cotton, Wood, Nylon
3. DDT, Polyester, Glass
4. Leather, Silk, Wool

An assertion (A) and a reason (R) are provided. Assertion (A): Using jute bags for shopping helps in reducing pollution. Reason (R): Jute is a biodegradable material, and jute bags can be reused multiple times. Choose the correct option regarding these statements.

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.

From the following food chains, identify the one that is most efficient in terms of energy transfer to the final consumer.

1. Grass → Grasshopper → Frog → Snake
2. Plants → Deer → Lion
3. Plants → Man
4. Phytoplankton → Zooplankton → Small Fish → Big Fish

Which of the following human activities has a detrimental effect on the environment?

1. Minimising the use of chlorofluorocarbons
2. Excessive use of disposable cups and plates
3. Maximising the use of reusable utensils for eating and drinking
4. Afforestation

If the energy available at the third trophic level is 50 kJ, calculate the energy that was available at the producer level.

1. 0.5 kJ
2. 5 kJ
3. 500 kJ
4. 5000 kJ

Identify the incorrect statement regarding ozone from the following options.

1. It is a deadly poisonous gas.
2. It shields the surface of the Earth from UV radiation from the sun.
3. It is used as a refrigerant and in fire extinguishers.
4. It is formed by combining an oxygen molecule with a free oxygen atom.

Consider the following statements: Assertion (A): A food web is a network of several food chains operating in an ecosystem. Reason (R): A food web decreases the stability of an ecosystem. Select the correct option regarding these statements.

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.

What is the primary reason that green plants are always positioned at the first trophic level in any food chain?

1. they exist over a large area.
2. they have very less concentration of harmful chemicals.
3. they have to feed a large number of herbivores.
4. they can synthesize food by photosynthesis.

Consider the following statements: Assertion (A): The accumulation of harmful chemicals is maximum in the organisms at the highest trophic level of a food chain. Reason (R): Harmful chemicals are sprayed on the crops to protect them from diseases and pests. Select the correct option regarding these statements.

1. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. Assertion (A) is true, but Reason (R) is false.
4. Assertion (A) is false, but Reason (R) is true.

Consider the following statements about ozone: (A) Ozone is a poisonous gas. (B) Ozone shields the earth's surface from infrared radiation from the sun. (C) Ozone is a product of UV radiation acting on oxygen molecules. (D) At the lower level of the earth's atmosphere, ozone performs its most essential function. Which of the given options represents the correct statements?

1. (A) and (B)
2. (A) and (C)
3. (B) and (C)
4. (B) and (D)