If the dark period is interrupted by flashes of light `"____________"` plant will not flower.

Answer

To answer the question "If the dark period is interrupted by flashes of light, '____________' plant will not flower," we need to understand the concept of photoperiodism in plants.

### Step-by-Step Solution:

1. **Understand Photoperiodism**: Photoperiodism is the physiological reaction of organisms to the length of day or night. Plants respond to the duration of light and darkness to regulate flowering and other growth processes.

2. **Classify Plants Based on Light Requirements**: Plants can be classified into three categories based on their light requirements:
- **Short Day Plants**: These plants require a longer dark period (night) and a shorter light period (day) to flower. They typically flower when the nights are longer than a certain critical length.
- **Long Day Plants**: These plants require a longer light period and a shorter dark period to flower. They usually flower when the nights are shorter than a certain critical length.
- **Day Neutral Plants**: These plants do not have a specific requirement for day length and can flower regardless of the light conditions.

3. **Analyze the Effect of Interrupting the Dark Period**: In the case of short day plants, if the dark period is interrupted by flashes of light, it disrupts the necessary long night duration that these plants require to initiate flowering. Therefore, they will not flower if their dark period is interrupted.

4. **Conclusion**: Since the question specifically mentions the interruption of the dark period, the correct answer to fill in the blank is "short day."

### Final Answer:
If the dark period is interrupted by flashes of light, "short day" plant will not flower.

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