Dark reaction of photosynthesis is driven by ______ and the product of most crucial step of dark reaction undergoes _______

Options

A. Light, phosphorylation
B. Darkness, regeneration
C. Products of light reaction, reduction
D. Products of light reaction, carboxylation

Answer

To solve the question regarding the dark reaction of photosynthesis, we will break it down step by step.

### Step-by-Step Solution:

1. **Understanding Dark Reactions**:
- Dark reactions, also known as the Calvin Cycle, occur in the stroma of chloroplasts and do not directly require light. However, they are dependent on the products of the light reactions.

2. **Identifying the Driver of Dark Reactions**:
- The dark reactions are driven by the products of the light reactions, which are ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). These molecules provide the energy and reducing power necessary for the synthesis of glucose from carbon dioxide.

3. **Identifying the Crucial Step in Dark Reactions**:
- The most crucial step in the dark reactions is the conversion of carbon dioxide into glucose. This process involves a series of reactions where carbon dioxide is fixed and reduced to form glucose.

4. **Understanding the Product of the Crucial Step**:
- The product of the most crucial step of the dark reaction is glucose. This glucose can undergo further processes such as glycolysis or can be utilized in cellular respiration.

5. **Filling in the Blanks**:
- The first blank can be filled with "ATP and NADPH" since they drive the dark reactions.
- The second blank can be filled with "reduction" as the crucial step involves the reduction of carbon dioxide to glucose.

### Final Answer:
The dark reaction of photosynthesis is driven by **ATP and NADPH** and the product of the most crucial step of the dark reaction undergoes **reduction**.

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