Rapid inter - nodal elongation is caused due to which hormone ?

Options

A. Gibberrllin
B. Auxin
C. Cytokinin
D. Abscisic acid

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which hormone is responsible for rapid inter-nodal elongation in plants.

2. **Identifying Plant Hormones**: There are several plant hormones, including auxins, gibberellins, cytokinins, and abscisic acid. Each of these hormones has specific functions in plant growth and development.

3. **Focusing on Gibberellins**: Gibberellins are known for their role in promoting growth, particularly in stem elongation and germination. They are crucial in processes that involve rapid growth.

4. **Defining Inter-nodal Elongation**: Inter-nodal elongation refers to the increase in length between the nodes (the points on a stem where leaves are attached). This elongation is essential for the overall height and structure of the plant.

5. **Linking Gibberellins to Inter-nodal Elongation**: Gibberellins are specifically known to promote the rapid elongation of internodes. This means that when gibberellins are present, they stimulate the cells in the internodes to elongate more quickly than they would without the hormone.

6. **Conclusion**: Based on the functions of gibberellins, it is clear that the hormone responsible for rapid inter-nodal elongation is gibberellin.

**Final Answer**: Gibberellin is the hormone responsible for rapid inter-nodal elongation.

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