Which of the following does not have any place in the ecological pyramids?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Detritus
Option (1) Plants — Has a place. Plants form the base.
Option (2) Frog — Has a place. A consumer.
Option (3) Detritus — No place. Detritus is the dead biomass on which decomposers (saprophytes) feed. NCERT notes as a limitation of ecological pyramids that saprophytes are given no place in them; plants, frogs and birds are all placed in trophic levels.
Option (4) Birds — Has a place. A consumer.
NCERT Extract:
Ecological Pyramids – “… However, there are certain limitations of ecological pyramids such as it does not take into account the same species belonging to two or more trophic levels. It assumes a simple food chain, something that almost never exists in nature; it does not accommodate a food web. Moreover, saprophytes are not given any place in ecological pyramids even though they play a vital role in the ecosystem.”
Energy Flow – “… When any organism dies it is converted to detritus or dead biomass that serves as an energy source for decomposers.”