Which one can induce flowering in long day plants ?

Options

A. cytokinin
B. auxin
C. Gibberellin
D. Ethylene

Answer

To determine which hormone can induce flowering in long-day plants, we will analyze the options provided and identify the correct one.

### Step-by-Step Solution:

1. **Understanding Long-Day Plants**:
- Long-day plants require a longer duration of light to initiate flowering. They typically flower when the day length exceeds a certain threshold.

2. **Reviewing the Options**:
- The options provided are:
- A) Cytokinin
- B) Auxin
- C) Gibberellin
- D) Ethylene

3. **Analyzing Each Option**:
- **A) Cytokinin**:
- Cytokinins are primarily involved in promoting cell division and growth. They do not play a significant role in inducing flowering in long-day plants.
- **Conclusion**: Incorrect.

- **B) Auxin**:
- Auxins are hormones that promote apical dominance and are involved in various growth processes. However, they do not specifically induce flowering in long-day plants.
- **Conclusion**: Incorrect.

- **C) Gibberellin**:
- Gibberellins are known to promote stem elongation and play a crucial role in flowering, especially in long-day plants. They facilitate the transition from vegetative growth to flowering by promoting cell division and elongation.
- **Conclusion**: Correct.

- **D) Ethylene**:
- Ethylene is primarily known for its role in fruit ripening and does not induce flowering in long-day plants.
- **Conclusion**: Incorrect.

4. **Final Answer**:
- The hormone that can induce flowering in long-day plants is **Gibberellin**.