The process of photosynthesis and respiration cause the cycling of........ through the environment.

Options

A. carbon
B. water
C. nitrogen
D. hydrogen

Answer

**Step-by-Step Solution:**

1. **Understanding Photosynthesis**:
- Photosynthesis is the process by which plants convert carbon dioxide and water into glucose (a type of sugar) and oxygen using sunlight and chlorophyll.
- The equation for photosynthesis can be summarized as:
\[ 6CO_2 + 6H_2O + light \rightarrow C_6H_{12}O_6 + 6O_2 \]
- Here, carbon dioxide (CO2) is absorbed from the atmosphere, and oxygen (O2) is released.

2. **Understanding Respiration**:
- Respiration is the process by which living organisms, including plants, break down glucose to release energy. This process uses oxygen and produces carbon dioxide as a byproduct.
- The equation for respiration can be summarized as:
\[ C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + energy \]
- In this process, oxygen is consumed, and carbon dioxide is released back into the atmosphere.

3. **The Cycling of Carbon**:
- The two processes are interconnected. During photosynthesis, carbon dioxide is taken in and converted into organic compounds, while during respiration, carbon dioxide is released back into the atmosphere.
- This continuous exchange of carbon dioxide between plants and the environment illustrates the carbon cycle.

4. **Conclusion**:
- Therefore, the answer to the question is that the processes of photosynthesis and respiration cause the cycling of **carbon** through the environment.

**Final Answer**: Carbon

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