Two food chains are shown. tree `rarr` aphid `rarr` insectivorous bird `rarr` bird of prey phytoplankton `rarr` zooplankton `rarr` plarikton-feeding fish `rarr` carnivorous fish Which diagram is a pyramid of energy representing both food chains?

Options

A.
B.
C.
D.

Answer

To determine which diagram represents a pyramid of energy for the given food chains, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Food Chains**:
- The first food chain is: Tree → Aphid → Insectivorous Bird → Bird of Prey.
- The second food chain is: Phytoplankton → Zooplankton → Plankton-feeding Fish → Carnivorous Fish.

2. **Define Pyramid of Energy**:
- A pyramid of energy is a graphical representation that shows the amount of energy available at each trophic level in an ecosystem. It typically has a broad base and narrows towards the top, indicating that energy decreases as you move up trophic levels.

3. **Identify Trophic Levels**:
- In the first food chain:
- 1st Trophic Level: Tree (Producers)
- 2nd Trophic Level: Aphid (Primary Consumers)
- 3rd Trophic Level: Insectivorous Bird (Secondary Consumers)
- 4th Trophic Level: Bird of Prey (Tertiary Consumers)
- In the second food chain:
- 1st Trophic Level: Phytoplankton (Producers)
- 2nd Trophic Level: Zooplankton (Primary Consumers)
- 3rd Trophic Level: Plankton-feeding Fish (Secondary Consumers)
- 4th Trophic Level: Carnivorous Fish (Tertiary Consumers)

4. **Energy Transfer**:
- Energy transfer between trophic levels typically follows the 10% rule, where only about 10% of the energy is passed on to the next level, and the rest is lost as heat or used for metabolic processes.

5. **Shape of the Pyramid**:
- The pyramid of energy is always upright, meaning that the energy decreases as you move from the base (producers) to the top (top predators).

6. **Select the Correct Diagram**:
- Based on the definitions and characteristics of a pyramid of energy, the correct diagram representing both food chains must show an upright pyramid structure, reflecting the decrease in energy from producers to top consumers.

### Conclusion:
- The correct option for the pyramid of energy representing both food chains is **Option C**, which illustrates the upright shape of the energy pyramid.