which pair is wrong ?

Options

A. `C_3` - Maize
B. `C_4` - Kranz anatomy
C. Calvin cycle - PGA
D. Hatch & Slack cycle - OAA

Answer

To solve the question "Which pair is wrong?" regarding photosynthesis in higher plants, we will analyze the provided statements about different types of plants and their characteristics.

### Step-by-Step Solution:

1. **Identify the Types of Plants**:
- C3 plants
- C4 plants

2. **C3 Plants**:
- C3 plants primarily include species like mustard and spinach. They utilize the Calvin cycle for photosynthesis and have a three-carbon compound (3-PGA) as the first stable product of carbon fixation.

3. **C4 Plants**:
- C4 plants, such as maize and sorghum, have a different mechanism of photosynthesis that involves a four-carbon compound (oxaloacetate) as the first product. They exhibit Kranz anatomy, which includes two types of cells: bundle sheath cells and mesophyll cells.

4. **Review the Given Statements**:
- The first statement claims that "C3 is maize." This is incorrect because maize is a C4 plant.
- The second statement correctly identifies that the Calvin cycle involves PGA (phosphoglycerate).
- The third statement correctly describes C4 plants as having Kranz anatomy and being more advanced plants found in tropical regions.

5. **Conclusion**:
- The statement that "C3 is maize" is the wrong pair. Therefore, the answer to the question is that the first option is incorrect.

### Final Answer:
The wrong pair is: **C3 is maize.**