`CO_2` acceptor during `C_3`-cycle is

Options

A. 5-carbon ketose sugar
B. Hexose sugar
C. RuBP
D. Both (1) & (3)

Answer

To solve the question regarding the CO₂ acceptor during the C₃ cycle, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the C₃ Cycle**: The C₃ cycle, also known as the Calvin cycle, is a crucial part of photosynthesis where carbon dioxide is fixed into organic compounds. This cycle occurs in the stroma of chloroplasts and does not require light directly.

**Hint**: The C₃ cycle is also referred to as the Calvin cycle and is essential for carbon fixation.

2. **Identify the CO₂ Acceptor**: In the C₃ cycle, the primary molecule that accepts carbon dioxide (CO₂) is ribulose 1,5-bisphosphate (RUBP). This molecule is a 5-carbon compound that plays a key role in the initial step of the cycle.

**Hint**: Look for the molecule that directly interacts with CO₂ at the beginning of the Calvin cycle.

3. **Analyze the Options**: The options provided are:
- 5 carbon ketose sugar
- Hexose sugar
- RUBP
- Both 1 and 3

Since RUBP is indeed a 5-carbon ketose sugar, it fits both the description of being a 5-carbon compound and being the CO₂ acceptor.

**Hint**: Consider the definitions of the terms provided in the options to see which ones are correct.

4. **Determine the Correct Answer**: Since RUBP is a 5-carbon ketose sugar and it is the CO₂ acceptor in the C₃ cycle, the correct answer is that both options 1 (5 carbon ketose sugar) and 3 (RUBP) are correct.

**Hint**: If an option states "both 1 and 3," check if both statements are true to confirm that option is correct.

### Final Answer:
The CO₂ acceptor during the C₃ cycle is **both 1 and 3** (5 carbon ketose sugar and RUBP).