Q. In an ecosystem if the Net Primary Productivity (NPP) of first trophic level is: $100x\,(kcal\,m^{-2})yr^{-1}$ what would be the GPP (Gross Primary Productivity) of the third trophic level of the same ecosystem?
A) $10x\,(kcal\,m^{-2})yr^{-1}$
B) $\frac{100x}{3x}\,(kcal\,m^{-2})yr^{-1}$
C) $\frac{x}{10}\,(kcal\,m^{-2})yr^{-1}$
D) $x\,(kcal\,m^{-2})yr^{-1}$
Explanation
[Solution by Claude - not from source] By the 10% law, the second trophic level gets $10x$ and the third gets $x$. (Medium confidence: question is ambiguous about GPP vs NPP.) Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.