Abscisic acid causes

Options

A. Seed dormancy
B. Apical dominance
C. Root initiation
D. Phototropism.

Answer

**Step-by-Step Solution:**

1. **Understanding Abscisic Acid (ABA)**: Abscisic acid, commonly known as ABA, is a plant hormone that plays a crucial role in various plant processes, particularly in response to stress conditions.

2. **Identifying the Role of ABA**: ABA is primarily known as a growth inhibitor. It helps plants cope with stress by slowing down growth and conserving resources.

3. **Effects of ABA**: The main effects of abscisic acid include:
- **Closing of Stomata**: ABA causes the stomata (tiny openings on leaves) to close, which reduces water loss during drought conditions.
- **Inhibition of Plant Metabolism**: It slows down metabolic processes, which helps the plant to survive unfavorable conditions.
- **Inducing Seed Dormancy**: ABA promotes seed dormancy, preventing seeds from germinating under unsuitable conditions.

4. **Analyzing the Options**: The question provides four options:
- Seed Dormancy
- Apical Dominance
- Root Initiation
- Phototropism

5. **Determining the Correct Answer**: Among the options, the one that is directly caused by abscisic acid is **Seed Dormancy**. This is because ABA inhibits seed germination and promotes dormancy, ensuring that seeds remain inactive until conditions are favorable for growth.

6. **Conclusion**: Therefore, the correct answer to the question "Abscisic acid causes" is **Seed Dormancy**.

---