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

Hint: The pyramid of ecosystem is a graphical representation of various living organisms at different levels and their relationship with each other. There are three types of pyramids - Pyramid of number, biomass and energy.

Complete Answer:
An ecological pyramid can be defined as a graphical 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.

Option A: The given statement is correct as the pyramid of numbers is inverted. The first trophic level in this pyramid is a single tree which supports the consumers. The consumers are far higher in number than the single tree.

Option B: The pyramid of biomass in the sea is inverted because of the pattern of the food chain in the ocean. It is observed that 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. These phytoplanktons grow and reproduce rapidly. Hence, the pyramid of biomass has a small base, with the consumer biomass exceeding the producer biomass. Hence, the pyramid takes inverted biomass. Therefore, this statement is correct.

Option C: The 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. Therefore, this statement is incorrect.

Option D: The given statement is incorrect as pyramids can account properly for the species which belong to more than two trophic levels. There are almost 4-5 organisms in a normal trophic level.

Thus, the correct option is C) A, B.

Note: The importance of pyramids of ecosystem are,
- They can show the efficiency of energy transfer.
- They can show the feeding habits of various organisms belonging to different ecosystems.
- They can be used for monitoring ecosystems and also help in prevention of any kind of further damage to it.