_______ is a period when growth and development is temporarily stopped.

Options

A. Dormancy
B. Abscission
C. Senescence
D. Vernalisation

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for a term that describes a period when growth and development in plants is temporarily halted.

2. **Identifying the Options**: The options provided are likely terms related to plant growth stages. Common terms include dormancy, abscission, senescence, and vernalization.

3. **Analyzing Each Option**:
- **Dormancy**: This is a period when a plant's growth and development slow down significantly or stop altogether. This is often a survival mechanism during unfavorable conditions.
- **Abscission**: This refers to the process where leaves or other parts of the plant detach and fall off. It does not indicate a halt in growth but rather a shedding process.
- **Senescence**: This is the process of aging in plants, where they undergo changes leading to death. It is not a temporary stop but a progression towards the end of life.
- **Vernalization**: This is the process of inducing flowering in plants through exposure to prolonged cold. It is not related to stopping growth.

4. **Conclusion**: Among the options, dormancy is the only term that describes a period when growth and development are temporarily stopped. Therefore, the correct answer is **dormancy**.

5. **Additional Information**: The phytohormone responsible for inducing dormancy in plants is abscisic acid (ABA).

**Final Answer**: Dormancy

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