Question

Which ecological pyramid can never be inverted?

• A. Biomass pyramid
• B. Numbers pyramid
• C. Energy pyramid
• D. Productivity pyramid

Hint:

Ecological pyramids: \[ \boxed{ \begin{aligned} \text{Energy pyramid} &\rightarrow \text{Always upright}\\ \text{Biomass pyramid} &\rightarrow \text{May be inverted}\\ \text{Numbers pyramid} &\rightarrow \text{May be inverted} \end{aligned} } \]

Answer 1

The Correct Option is C

Step 1: Recall why energy pyramids behave differently from the others.
Biomass and numbers pyramids can sometimes invert in special cases, such as a few large trees supporting many small insects.
Step 2: Bring in the physics of energy transfer.
The second law of thermodynamics tells us that a lot of energy is lost as heat every time it passes from one trophic level to the next, so each higher level always has less usable energy than the one below it.
Step 3: Apply this consistently across every ecosystem.
Since this energy loss happens without exception, the energy available at higher trophic levels can never exceed that at lower ones, so the energy pyramid always stays upright.
\[ \boxed{\text{Energy pyramid}} \]