In an ecosystem the rate of production of organic matter during photosynthesis is termed as

Options

A. Gross primary productivity
B. secondary productivity
C. Net productivity
D. net primary productivity

Answer

To answer the question "In an ecosystem the rate of production of organic matter during photosynthesis is termed as", we will analyze the options provided and determine the correct term based on our understanding of ecological productivity.

### Step-by-Step Solution:

1. **Understanding Photosynthesis**:
- Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll. During this process, they convert carbon dioxide and water into glucose and oxygen.

2. **Defining Gross Primary Productivity (GPP)**:
- Gross Primary Productivity (GPP) refers to the total amount of organic matter (biomass) produced by photosynthesis in a given area and time. It represents the total energy captured by plants.

3. **Defining Net Primary Productivity (NPP)**:
- Net Primary Productivity (NPP) is the amount of organic matter that remains after the plants have used some of the energy for their own respiration. It is calculated as NPP = GPP - Respiration.

4. **Defining Secondary Productivity**:
- Secondary productivity is the rate at which consumers (heterotrophs) convert the organic matter they consume into their own biomass. This is not directly related to the photosynthesis process.

5. **Defining Net Productivity**:
- Net productivity generally refers to the energy available to the next trophic level after accounting for energy lost through respiration. This term is broader and can apply to both primary and secondary producers.

6. **Conclusion**:
- Since the question specifically asks for the rate of production of organic matter during photosynthesis, the correct term is **Gross Primary Productivity (GPP)**.

### Final Answer:
The rate of production of organic matter during photosynthesis in an ecosystem is termed as **Gross Primary Productivity (GPP)**.

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