Class 10 Science


Our Environment NCERT Exemplar Problem

MCQs Part 2

Question 11: Excessive exposure of humans to UV rays results in

  1. Damage to immune system
  2. Damage to lungs
  3. Skin cancer
  4. Peptic ulcers
  1. (i) and (ii)
  2. (ii) and (iv)
  3. (i) and (iii)
  4. (iii) and (iv)

    Answer: (c) (i) and (iii)

Question 12: In the following groups of materials, which group (s) contains only non-biodegradable items?

  1. Wood, paper, leather
  2. Polythene, detergent, PVC
  3. Plastic, detergent, grass
  4. Plastic, bakelite, DDT
  1. (iii)
  2. (iv)
  3. (i) and (iii)
  4. (ii) and (iv)

    Answer: (d) (ii) and (iv)

Question 13: Which of the following limits the number of trophic levels in a food chain?

  1. Decrease in energy at higher trophic levels
  2. Defficient food supply
  3. Polluted air
  4. Water

    Answer: (a) Decrease in energy at higher trophic levels

Question 14: Which of the statement is incorrect?

  1. All green plants and blue green algae are producers
  2. Green plants get their food from organic compounds
  3. Producers prepare their own food from inorganic compounds
  4. Plants convert solar energy into chemical energy

    Answer: (b) Green plants get their food from organic compounds

Question 15: Which group of organisms are not constituents of a food chain?

  1. Grass, lion, rabbit, wolf
  2. Plankton, man, fish, grasshopper
  3. Wolf, grass, snake, tiger
  4. Frog, snake, eagle, grass, grasshopper
  1. (i) and (iii)
  2. (iii) and (iv)
  3. (ii) and (iii)
  4. (i) and (iv)

    Answer: (c) (ii) and (iii)

Question 17: The percentage of solar radiation absorbed by all the green plants for the process of photosynthesis is about

  1. 1%
  2. 5%
  3. 8%
  4. 10%

    Answer: (a) 1%

Question 18: Assume T1, T2, T3 and T4 are the various trophic levels from bottom to top in a pyramid. At which trophic level is maximum energy available?

  1. T4
  2. T2
  3. T1
  4. T3

    Answer: (c) T1

Question 18: What will happen if deer is missing in the food chain given below?
Grass → Deer → Tiger

  1. The population of tiger increases
  2. The population of grass decreases
  3. Tiger will start eating grass
  4. The population of tiger decreases and the population of grass increases

    Answer: (d) The population of tiger decreases and the population of grass increases

Question 19: The decomposers in an ecosystem

  1. Convert inorganic material, to simpler forms
  2. Convert organic material to inorganic forms
  3. Convert inorganic materials into organic compounds
  4. Do not breakdown organic compounds

    Answer: (b) Convert organic materials to inorganic forms

Question 20: If a grass hopper is eaten by a frog, then the energy transfer will be from

  1. Producer to decomposer
  2. Producer to primary consumer
  3. Primary consumer to secondary consumer
  4. Secondary consumer to primary consumer

    Answer: (c) Primary consumer to secondary consumer

Question 21: Disposable plastic plates should not be used because

  1. They are made of materials with light weight
  2. They are made of toxic materials
  3. They are made of biodegradable materials
  4. They are made of non-biodegradable materials

    Answer: (d) They are made of non-biodegradable materials