Available biomass for the consumption to heterotrophs is

Options

A. GPP
B. NPP
C. Secondary productivity
D. Net productivity

Answer

To solve the question regarding the available biomass for consumption by heterotrophs, we can follow these steps:

### Step 1: Understand the terms
- **Heterotrophs**: These are organisms that cannot produce their own food and rely on consuming other organisms, primarily plants or organic matter.
- **Biomass**: This refers to the total mass of living matter in a given area or volume, which can be consumed by heterotrophs.

### Step 2: Identify the relevant productivity types
- **Gross Primary Productivity (GPP)**: This is the total amount of organic matter produced by photosynthesis in a given area.
- **Net Primary Productivity (NPP)**: This is the amount of organic matter that remains after the plants have used some of it for their own respiration. It represents the biomass available for consumption by heterotrophs.
- **Secondary Productivity**: This refers to the generation of biomass by heterotrophs through the consumption of primary producers.
- **Net Productivity**: This term can sometimes refer to the net gain of biomass in an ecosystem, but it is less commonly used in this context.

### Step 3: Determine the correct answer
Since the question specifically asks for the biomass available for consumption by heterotrophs, we need to focus on the type of productivity that represents this available biomass.

- **NPP (Net Primary Productivity)** is the correct answer because it is the biomass produced by primary producers (plants) that is available for consumption by heterotrophs.

### Conclusion
Thus, the available biomass for the consumption of heterotrophs is **Net Primary Productivity (NPP)**.

### Final Answer
**B. Net Primary Productivity**

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