In an ecosystem,

Options

A. Primary producers are more than primary consumers
B. Primary consumers are larger than primary producers
C. Secondary consumers are larger than primary producers
D. Primary consumers least depend on primary producers

Answer

### Step-by-Step Solution:

1. **Understanding Ecosystem Components**:
- In an ecosystem, organisms are categorized into different trophic levels. The primary producers are at the base of the food chain, followed by primary consumers, secondary consumers, and so on.

2. **Defining Primary Producers**:
- Primary producers are autotrophs, meaning they can produce their own food. They typically do this by trapping energy from sunlight (photosynthesis) or from inorganic molecules (chemosynthesis).

3. **Role of Primary Producers**:
- The main function of primary producers is to convert solar or chemical energy into energy-rich organic molecules, which serve as food for primary consumers.

4. **Energy Transfer in Ecosystems**:
- Energy transfer occurs from one trophic level to the next. However, due to the inefficiency of energy transfer, only about 10% of the energy from one level is passed to the next. This is known as the 10% law of energy transfer.

5. **Implications of the 10% Law**:
- Since only 10% of energy is transferred to the next trophic level, there must be a larger number of primary producers than primary consumers to support the energy needs of the consumers. If there were more consumers than producers, they would quickly deplete the available energy.

6. **Analyzing the Options**:
- A. Primary producers are more than primary consumers. (True)
- B. Primary consumers are larger than primary producers. (False)
- C. Secondary consumers are larger than primary producers. (Not necessarily true)
- D. Primary consumers least depend on primary producers. (False)

7. **Conclusion**:
- Based on the analysis, the correct answer is **Option A: Primary producers are more than primary consumers**.