PEP is primary `CO_(2)` acceptor in

Options

A. `C_(4)` plants
B. `C_(3)` plant
C. `C_(2)` plants
D. both `C_(3)` and `C_(4)` plants

Explanation

To determine which type of plants utilize PEP (phosphoenolpyruvate) as the primary CO2 acceptor, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding PEP**: PEP is a three-carbon compound that acts as a CO2 acceptor in certain plants. It plays a crucial role in the process of photosynthesis, particularly in the carbon fixation stage.

2. **Types of Plants**: There are different types of plants based on their photosynthetic pathways, mainly C3, C4, and CAM (Crassulacean Acid Metabolism) plants. Each type has a different mechanism for CO2 fixation.

3. **C4 Plants**: C4 plants, such as maize and sugarcane, have evolved a specialized mechanism to efficiently fix CO2. In these plants, PEP acts as the primary CO2 acceptor. The enzyme PEP carboxylase catalyzes the reaction between PEP and CO2 to form oxaloacetate, which is then converted into malate or aspartate.

4. **Avoiding Photorespiration**: One of the advantages of using PEP as a CO2 acceptor in C4 plants is that it minimizes photorespiration. Photorespiration is a process that can lead to the loss of CO2 and energy, especially under high oxygen concentrations. By using PEP, C4 plants can effectively concentrate CO2 and reduce the chances of photorespiration.

5. **Conclusion**: Based on the above information, we can conclude that PEP is the primary CO2 acceptor in C4 plants. C3 plants primarily use RuBP (ribulose bisphosphate) for CO2 fixation and do not utilize PEP in this role.

### Final Answer:
PEP is the primary CO2 acceptor in **C4 plants**.