If night period is broken by a single flash of red light, followed by far red, red and finally far red light, what will be its effect on flowering in short day plants

Options

A. no flowering
B. poor flowering
C. delayed flowering
D. no effect on flowering in SDP

Answer

To solve the question regarding the effect of a sequence of light flashes on flowering in short day plants, we can break it down into several steps:

### Step-by-Step Solution:

1. **Understanding Short Day Plants**:
- Short day plants are those that require longer nights and shorter days to induce flowering. They typically flower when the duration of darkness exceeds a certain critical length.

**Hint**: Remember that short day plants thrive under conditions of extended darkness.

2. **Effect of Light on Flowering**:
- In short day plants, exposure to red light during the night inhibits flowering. This is because red light is perceived by phytochromes, which are light-sensitive proteins that regulate flowering.

**Hint**: Consider how different wavelengths of light affect the plant's internal signaling mechanisms.

3. **Sequence of Light Exposure**:
- The question specifies a sequence of light exposure: a flash of red light, followed by far red light, then red light again, and finally far red light.
- The first flash of red light will prevent flowering.
- The subsequent flash of far red light will reverse the effect of the red light and induce flowering.
- The next red light flash will again inhibit flowering.
- The final far red light flash will again induce flowering.

**Hint**: Pay attention to how each light flash interacts with the previous one and the cumulative effect on flowering.

4. **Final Effect on Flowering**:
- Since the last light exposure is far red light, which induces flowering, the final outcome will be that flowering will occur in the short day plant despite the earlier red light flashes.

**Hint**: Focus on the last action in a sequence of events, as it often determines the final outcome.

### Conclusion:
The effect of the sequence of light flashes on flowering in short day plants is that the last flash of far red light will induce flowering. Therefore, the final result is that flowering will occur in the short day plant.