which one of the following pyramid is generally inverted?

Options

A. pyramid of number in grassland ecosystem
B. pyramid of biomass in a grassland ecosystem
C. pyramid of number in sea
D. pyramid of biomass in sea

Answer

To determine which pyramid is generally inverted, we need to analyze the different types of ecological pyramids: pyramid of numbers, pyramid of biomass, and pyramid of energy.

### Step-by-Step Solution:

1. **Understand the Concept of Ecological Pyramids**:
- Ecological pyramids represent the distribution of biomass, numbers, or energy among trophic levels in an ecosystem.
- The base of the pyramid typically consists of producers, followed by primary consumers, secondary consumers, and tertiary consumers.

2. **Identify Types of Ecological Pyramids**:
- **Pyramid of Numbers**: Represents the number of individual organisms at each trophic level.
- **Pyramid of Biomass**: Represents the total biomass (weight of living matter) at each trophic level.
- **Pyramid of Energy**: Represents the flow of energy through each trophic level.

3. **Evaluate the Pyramid of Biomass in Different Ecosystems**:
- In a **grassland ecosystem**, the pyramid of biomass is upright because there are many producers (plants) at the base, followed by fewer herbivores and even fewer carnivores.
- In a **marine ecosystem (ocean)**, the pyramid of biomass can be inverted. This is because the biomass of the primary producers (like phytoplankton) is low compared to the biomass of the consumers (like small fish and larger fish).

4. **Conclusion**:
- The pyramid of biomass in the marine ecosystem is generally inverted due to the low biomass of producers compared to the higher biomass of consumers.

### Final Answer:
The pyramid that is generally inverted is the **Pyramid of Biomass in the Marine Ecosystem**.