Which of the following uses maximum energy ?

Options

A. Primary producer
B. Primary consumers
C. Secondary consumers
D. Decomposer

Answer

To determine which group uses maximum energy among primary producers, primary consumers, secondary consumers, and decomposers, we can analyze the energy flow in an ecosystem based on trophic levels.

### Step-by-Step Solution:

1. **Identify Trophic Levels**:
- The first trophic level consists of **primary producers** (e.g., plants).
- The second trophic level consists of **primary consumers** (e.g., herbivores).
- The third trophic level consists of **secondary consumers** (e.g., carnivores that eat herbivores).
- The fourth trophic level consists of **tertiary consumers** (e.g., top predators like lions).

2. **Understand Energy Transfer**:
- Energy is transferred from one trophic level to the next. However, according to the **10% energy law**, only about 10% of the energy from one level is transferred to the next level. The remaining 90% is lost primarily as heat or used for metabolic processes.

3. **Analyze Energy at Each Level**:
- At the **first trophic level** (primary producers), the total energy available is the highest since they convert sunlight into energy through photosynthesis.
- At the **second trophic level** (primary consumers), only 10% of the energy from the primary producers is available.
- At the **third trophic level** (secondary consumers), only 10% of the energy from the primary consumers is available.
- At the **fourth trophic level** (tertiary consumers), only 10% of the energy from the secondary consumers is available.

4. **Conclusion**:
- Since energy decreases as it moves up the trophic levels, the group that uses maximum energy is the **primary producers**. They are the foundation of the energy pyramid and have the most energy available.

### Final Answer:
The group that uses maximum energy is **Primary Producers**.