Question

Select the correct statements regarding the pyramids of ecosystem
(A) The pyramid of number of a tree ecosystem is inverted
(B) Pyramid of biomass in sea is inverted
(C) Pyramid of energy is mostly upright except in one special case
(D) Pyramids do not properly account the species belonging to two or more trophic levels

• A. A, B, C, D
• B. A, B, D
• C. A, B
• D. A, B, C

Answer 1

The correct option is C A, B

• An ecological pyramid is a graphic representation of the relationship between organisms at various trophic levels in a food chain. The basis of an ecological pyramid is biomass, energy, and number.
• The pyramid of number of a tree ecosystem is inverted as the first trophic level is a single tree and the higher trophic levels have organisms more in number.
• Pyramid of biomass in the sea is inverted because of the pattern of the food chain in the ocean- the biomass of zooplankton is greater than phytoplankton, the producer because of their small size and low mass and the predatory fish is much larger than zooplankton.
• Pyramid of energy is always upright because when energy flows from one trophic level to the next trophic level, some energy is always lost as heat at each step. There are no exceptions.
• Pyramids can properly account for the species belonging to more than two trophic levels. Normal trophic levels are often 4 to 5 organisms long as much of the energy is lost between levels.
• So the correct option is C.