Arrange the amount of energy in a sequence from the highest trophic level to the lowest trophic level (Pyramid of Energy):
(A) 10,000 J
(B) 1000 J
(C) 10 J
(D) 100 J
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (C), (D), (B), (A)
(C) 10 J — first: the highest trophic level, the tertiary consumers or top carnivores. By the 10 per cent law, only about 10 per cent of the energy at one level passes on to the next, so the top of the pyramid holds the least energy: 10 per cent of 100 J = 10 J. The sequence asked for therefore starts at the smallest value, not at 10,000 J.
(D) 100 J — second: the secondary consumers (small carnivores). They get 10 per cent of the 1000 J held by the herbivores, that is 100 J.
(B) 1000 J — third: the primary consumers (herbivores). They get 10 per cent of the 10,000 J held by the producers, that is 1000 J.
(A) 10,000 J — last: the producers, the lowest trophic level at the base of the pyramid. They hold the most energy because every other level depends on what they fix from sunlight. Option (1) gives this same chain read from the producers upwards, the reverse of what the question asks.
NCERT Extract:
Ecological Pyramids –
