Which of these plant hormones allows the plant to withstand extremely dry climates ?

Options

A. ABA
B. Auxin
C. Cytokinin
D. GA

Answer

To solve the question of which plant hormone allows the plant to withstand extremely dry climates, we will analyze each of the provided options step by step.

### Step 1: Identify the Options
The options given are:
1. Abscisic Acid (ABA)
2. Auxin
3. Cytokinin
4. Gibberellic Acid

### Step 2: Understand the Role of Each Hormone
- **Abscisic Acid (ABA)**: This hormone is known as the "stress hormone." It plays a crucial role in helping plants cope with stress conditions, particularly drought. ABA induces stomatal closure in leaves, which reduces water loss during periods of water scarcity.

- **Auxin**: This hormone is primarily involved in processes such as stem elongation and rooting. It does not play a significant role in helping plants withstand dry conditions.

- **Cytokinin**: Cytokinins are involved in promoting cell division and growth. They do not have a direct role in drought resistance.

- **Gibberellic Acid**: This hormone is responsible for various growth processes, including seed germination and stem elongation. It is not associated with drought resistance.

### Step 3: Conclusion
Based on the functions of each hormone, **Abscisic Acid (ABA)** is the correct answer as it helps plants withstand extremely dry climates by inducing stomatal closure to minimize water loss.

### Final Answer
The plant hormone that allows the plant to withstand extremely dry climates is **Abscisic Acid (ABA)**.

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