Select the incorrect function w.r.t gibberellin.

Options

A. Accelerates cell elongation only under in vitro conditions
B. They are weakly acidic hormones
C. First isolated from the fungus Gibberella fujikuroi
D. They occur naturally in plants

Answer

To determine the incorrect function with respect to gibberellin, we will analyze each of the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Gibberellin**: Gibberellins are plant hormones that play a crucial role in various growth processes, including stem elongation, germination, and flowering.

2. **Analyzing the Options**:
- **Option A**: "Accelerate cell elongation only under in vitro conditions."
- This statement suggests that gibberellins only work to accelerate cell elongation in laboratory conditions (in vitro). However, gibberellins are naturally occurring hormones that function in vivo (in the living plant). Therefore, this statement is incorrect.

- **Option B**: "They are weakly acidic hormones."
- Gibberellins, specifically gibberellic acid, are indeed weakly acidic. This statement is correct.

- **Option C**: "First isolated from the fungus Gibberella fujikuroi."
- Gibberellins were first isolated from the fungus Gibberella fujikuroi in 1926. This statement is also correct.

- **Option D**: "They occur naturally in plants."
- Gibberellins are naturally occurring hormones in plants. This statement is correct.

3. **Conclusion**: The only incorrect function with respect to gibberellin is **Option A**, which states that gibberellins accelerate cell elongation only under in vitro conditions.

### Final Answer:
**The incorrect function with respect to gibberellin is: "Accelerate cell elongation only under in vitro conditions."**

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