By looking at a plant externally can you tell whether a plant is`C_(3)or C_(4)?` When and how ?

Explanation

To determine whether a plant is a C3 or C4 type based on external observation, follow these steps:

### Step-by-Step Solution:

1. **Understanding C3 and C4 Plants**:
- C3 plants primarily use the Calvin cycle for photosynthesis, where carbon dioxide is fixed into a three-carbon compound (3-phosphoglycerate).
- C4 plants utilize a different pathway that initially fixes carbon dioxide into a four-carbon compound (oxaloacetate), which is then converted into malate or aspartate.

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