Pyramid of number in a pond ecosystem is

Options

A. inverted
B. upright
C. spindle - shaped
D. irregular

Answer

### Step-by-Step Solution

1. **Understanding the Pyramid of Numbers**: The pyramid of numbers is a graphical representation that shows the number of individual organisms at each trophic level in an ecosystem.

2. **Structure of the Pyramid in a Pond Ecosystem**:
- **Producers**: At the base of the pyramid, we have the producers (such as aquatic plants). They are the most numerous organisms in the pond ecosystem.
- **Primary Consumers**: The next level consists of primary consumers (herbivores that feed on the producers). Their numbers are fewer than the producers.
- **Secondary Consumers**: Above the primary consumers are the secondary consumers (carnivores that feed on primary consumers). They are even less in number compared to primary consumers.
- **Tertiary Consumers**: At the top of the pyramid are the tertiary consumers (top predators). Their numbers are the least among all trophic levels.

3. **Shape of the Pyramid**: In a pond ecosystem, the pyramid of numbers is typically upright. This means that as you move up from producers to tertiary consumers, the number of individuals decreases.

4. **Conclusion**: Based on the structure and the number of organisms at each trophic level, we can conclude that the pyramid of number in a pond ecosystem is upright.

5. **Final Answer**: Therefore, the correct answer is option 2, indicating that the pyramid of numbers in a pond ecosystem is always upright.