Which one of the following pairs, is not correctly matched ?

Options

A. Cytokinin - Cell division
B. IAA - Cell wall elongation
C. Abscissic Acid - Stomata! closure
D. Gibberellic Acid - Leaf fall

Answer

To determine which pair is not correctly matched, we will analyze each pair one by one based on the functions of the plant hormones mentioned.

### Step-by-Step Solution:

1. **Identify the First Pair: Cytokinin - Cell Division**
- Cytokinins are plant hormones that promote cell division in plant roots and shoots.
- **Conclusion**: This pair is correctly matched.

2. **Identify the Second Pair: IAA - Cell Wall Elongation**
- IAA stands for Indole Acetic Acid, which is a type of auxin. Auxins promote cell elongation by loosening the cell walls.
- **Conclusion**: This pair is correctly matched.

3. **Identify the Third Pair: Abscisic Acid - Stomatal Closure**
- Abscisic acid (ABA) is known as the stress hormone and plays a crucial role in closing stomata to reduce water loss, especially during water scarcity.
- **Conclusion**: This pair is correctly matched.

4. **Identify the Fourth Pair: Gibberellic Acid - Leaf Fall**
- Gibberellic acid (GA) is a plant hormone that promotes growth and is responsible for processes such as seed germination and stem elongation. It does not promote leaf fall; rather, it helps in the formation of leaves.
- **Conclusion**: This pair is not correctly matched.

### Final Answer:
The incorrect pair is **Gibberellic Acid - Leaf Fall**.

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