Which one prevents premature fall of fruits

Options

A. IAA
B. Ethylene
C. `GA_(3)`
D. Zeatin

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks which substance prevents the premature fall of fruits. We need to identify the correct plant hormone from the given options: IAA, ethylene, GA3, or zeatin.

2. **Identifying the Hormones:**
- **IAA (Indole-3-acetic acid)**: This is a type of auxin, which is known for its role in promoting plant growth and preventing abscission (the process of leaves and fruits falling off).
- **Ethylene**: This hormone is known to promote ripening and can actually lead to the premature falling of fruits and leaves.
- **GA3 (Gibberellic acid)**: This hormone is involved in various developmental processes in plants but does not specifically prevent the fall of fruits.
- **Zeatin**: This is a type of cytokinin that promotes cell division and growth but does not prevent fruit drop.

3. **Analyzing the Functions:**
- Auxins, particularly IAA, are responsible for preventing the abscission layer from forming, which helps keep fruits attached to the plant.
- Ethylene, on the other hand, promotes the abscission process, leading to the dropping of fruits.
- GA3 and zeatin do not have a direct role in preventing premature fruit fall.

4. **Conclusion:**
Based on the functions of the hormones, the correct answer is **IAA (Indole-3-acetic acid)**, as it prevents the premature fall of fruits.

**Final Answer:**
The substance that prevents the premature fall of fruits is **IAA (Indole-3-acetic acid)**.

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