Chemical reaction takes place during dark reaction of photosynthesis is

Options

A. photolysis
B. hydrolysis
C. carbon dioxide is bonded with RUBP
D. nitrogen fixation

Answer

### Step-by-Step Solution:

1. **Understanding Photosynthesis**: Photosynthesis is the process by which plants convert light energy into chemical energy stored in glucose. It occurs in two main stages: the light-dependent reactions and the light-independent reactions (dark reactions).

2. **Identifying the Dark Reaction**: The dark reaction, also known as the Calvin Cycle, occurs in the stroma of the chloroplasts and does not require light directly. Instead, it utilizes the products of the light-dependent reactions, specifically ATP and NADPH.

3. **Key Components of the Dark Reaction**:
- **Carbon Dioxide (CO2)**: The dark reaction begins with the fixation of carbon dioxide.
- **Ribulose 1,5-bisphosphate (RUBP)**: This is a 5-carbon sugar that combines with CO2 during the dark reaction.

4. **Chemical Reaction in the Dark Reaction**: The main chemical reaction can be summarized as:
\[ \text{CO2} + \text{RUBP} \rightarrow \text{3-phosphoglycerate (3-PGA)} \]
This reaction is catalyzed by the enzyme RuBisCO.

5. **Formation of Glucose**: Through a series of reactions in the Calvin Cycle, 3-PGA is eventually converted into glucose, which serves as food for the plant.

### Final Answer:
The chemical reaction that takes place during the dark reaction of photosynthesis is the fixation of carbon dioxide (CO2) with ribulose 1,5-bisphosphate (RUBP) to form 3-phosphoglycerate (3-PGA).

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