Question

What will be dry weight $\left(kg{m}^{–2}\right)$ of tertiary consumer in an ecosystem if the dry weight of primary consumer is $37kg{m}^{–2}$?

• A. $21kg{m}^{–2}$
• B. $11kg{m}^{–2}$
• C. $4kg{m}^{–2}$
• D. $1.5kg{m}^{–2}$

Answer 1

The correct option is D $1.5kg{m}^{–2}$

The pyramid of biomass shows a sharp decrease in biomass at higher trophic levels.

With less energy at higher trophic levels, there are usually fewer organisms as well. Organisms tend to be larger in size at higher trophic levels, but their smaller numbers result in less biomass.

Biomass is the total mass of organisms at a trophic level. As shown in the pyramid below, if the dry weight of primary consumer is $37kg{m}^{–2}$, then according to the 10% law, at each trophic level 10% energy is passed, so the tertiary consumer will recieve the least energy resulting in the least production of biomass. So the correct answer is $1.5kg{m}^{–2}$.