Name the hormone which stimulates trans- verse or isodiametric growth

Options

A. ethylene
B. GA
C. sodium salt of NAA
D. methionine

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks for the hormone that stimulates transverse or isodiametric growth. Isodiametric growth refers to growth that is roughly spherical, meaning the diameter remains the same in all directions.

2. **Identifying the Hormones**: The options provided are:
- Ethylene
- Gibberellic acid
- Sodium salt of NAA
- (An unspecified fourth option)

3. **Defining Isodiametric Growth**: Isodiametric growth is characterized by equal growth in all directions, leading to a roughly spherical shape. This type of growth is different from longitudinal growth, which is more elongated.

4. **Role of Ethylene**: Ethylene is known as a gaseous plant hormone that plays a significant role in various growth processes, including stimulating isodiametric growth. It is particularly known for promoting growth that is more uniform in all directions.

5. **Effects of Ethylene**: Ethylene not only stimulates isodiametric growth but also retards longitudinal growth. This means that while it encourages growth that is more rounded, it limits growth in a single direction.

6. **Source of Ethylene**: Ethylene is produced by all plant tissues and is also released by certain microorganisms. It is derived from the breakdown of the amino acid methionine.

7. **Solubility of Ethylene**: Ethylene is less soluble in water, which means it does not accumulate in plant cells. Instead, it diffuses out of the cells, allowing for its effects to be exerted on surrounding tissues.

8. **Conclusion**: Based on the information gathered, the hormone that stimulates transverse or isodiametric growth is ethylene.

**Final Answer**: Ethylene

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