Which of the following statements about ecological pyramids is/are correct?
1. The pyramid of numbers can take a spindle shape.
2. In the aquatic ecosystem, the pyramid of biomass can be inverted.
3. The pyramid of energy is always upright.

Select the correct answer using the codes given below:
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3

Question

Which of the following statements about ecological pyramids is/are correct?
1. The pyramid of numbers can take a spindle shape.
2. In the aquatic ecosystem, the pyramid of biomass can be inverted.
3. The pyramid of energy is always upright.

Select the correct answer using the codes given below:
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3

ONLiNE UPSC · Accepted Answer

Statement 1 is correct: The pyramid of numbers can take a spindle shape in ecosystems where the number of individuals is greater at the middle trophic levels than at the base or top. For example, in a forest ecosystem, there are few large producers (trees), a large number of herbivorous insects, and fewer top predators, forming a spindle-shaped pyramid.

Statement 2 is correct: In aquatic ecosystems, the pyramid of biomass can be inverted. This happens because phytoplankton (producers) have a lower biomass than zooplankton (primary consumers), but they reproduce rapidly, supporting the food chain despite their lower standing biomass.

Statement 3 is correct: The pyramid of energy is always upright because energy flow follows the laws of thermodynamics with energy loss as heat at each trophic level. No ecosystem can have more energy at higher trophic levels than at lower ones, making this pyramid always upright.

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Ecological Pyramids

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M Question 1	⏱ 0
Which of the following statements about ecological pyramids is/are correct? 1. The pyramid of numbers can take a spindle shape. 2. In the aquatic ecosystem, the pyramid of biomass can be inverted. 3. The pyramid of energy is always upright. Select the correct answer using the codes given below: (a) 1 only (b) 1 and 2 only (c) 2 and 3 only (d) 1, 2 and 3