Which of the following hormone is used for shoot differentiation in callus ?

Options

A. 2,4-D
B. Benzyl amino purine (BAP)
C. Deformylase
D. Gibberelic acid

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which hormone is used for shoot differentiation in callus. Callus is a mass of unorganized plant cells that can differentiate into various plant structures.

2. **Identifying the Options**: The options provided are:
- 2, 4-D (2, 4-Dichlorophenoxyacetic acid)
- Benzylaminopurine (BAP)
- D-formylase
- Gibberellic acid

3. **Analyzing Each Option**:
- **2, 4-D**: This is an auxin, primarily involved in promoting cell elongation and is not specifically used for shoot differentiation.
- **Benzylaminopurine (BAP)**: This is a synthetic cytokinin that promotes cell division and is known to stimulate shoot regeneration from callus tissue.
- **D-formylase**: This is an enzyme and does not play a role in plant hormone activity or shoot differentiation.
- **Gibberellic acid**: This hormone is mainly involved in seed germination and not in shoot differentiation.

4. **Conclusion**: Based on the analysis, the hormone that is used for shoot differentiation in callus is **Benzylaminopurine (BAP)**.

### Final Answer:
The hormone used for shoot differentiation in callus is **Benzylaminopurine (BAP)**.

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