Identify the correct one from the following as we move up from lower trophic level to the higher level in ecological pyramids

Options

A. Number increases in predatory food chain
B. Number increases in parasitic food chain
C. Energy increases in predatory food chain
D. Biomass decreases is aquatic food chain

Answer

To solve the question about ecological pyramids and the changes that occur as we move from lower trophic levels to higher trophic levels, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Ecological Pyramids**:
- Ecological pyramids represent the distribution of biomass, numbers, or energy among trophic levels in an ecosystem. As we move from lower to higher trophic levels, we need to analyze how different factors change.

2. **Analyzing the Options**:
- We have four options to evaluate:
1. Number of increase in predatory food chain.
2. Number increase in parasitic food chain.
3. Energy increase in predatory food chain.
4. Biomass decrease in aquatic food chain.

3. **Evaluating Option 1**:
- "Number of increase in predatory food chain":
- In a typical pyramid of numbers, as we move up to higher trophic levels (from plants to top carnivores), the number of organisms generally decreases. Therefore, this option is **incorrect**.

4. **Evaluating Option 2**:
- "Number increase in parasitic food chain":
- In a parasitic food chain, as we move from herbivores to carnivores, the number of parasites often increases because they rely on their hosts. Therefore, this option is **correct**.

5. **Evaluating Option 3**:
- "Energy increase in predatory food chain":
- In an energy pyramid, as we move from lower to higher trophic levels, energy decreases due to energy loss at each level (e.g., through metabolic processes). Thus, this option is **incorrect**.

6. **Evaluating Option 4**:
- "Biomass decrease in aquatic food chain":
- In aquatic ecosystems, the biomass can sometimes be inverted, but generally, biomass does not decrease as we move up trophic levels. This option is also **incorrect**.

7. **Conclusion**:
- The correct answer is **Option 2: Number increase in parasitic food chain**.