Which statement is incorrect w.r.t photoperiodism in plants?

Options

A. The site of perception of light/dark is cotyledons or embryo
B. It depends on duration of light/dark
C. Critical exposure of light/dark is required
D. When there is no correlation between exposure to light duration and induction of flowering response, plants are called day neutral plants

Answer

To determine which statement is incorrect with respect to photoperiodism in plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Photoperiodism**: Photoperiodism is the response of plants to the lengths of day and night. It influences flowering and other developmental processes in plants.

2. **Categorize Plants Based on Photoperiod**:
- **Short Day Plants (SDP)**: These plants require a longer duration of darkness (shorter light periods) to flower.
- **Long Day Plants (LDP)**: These plants require a longer duration of light (shorter dark periods) to flower.
- **Day-Neutral Plants**: These plants do not depend on the duration of light or darkness for flowering.

3. **Identify the Site of Perception**: The leaves are the primary site for the perception of light and dark durations. Hormones produced in the leaves are responsible for signaling flowering.

4. **Analyze the Statements**:
- Check each statement provided in the question regarding photoperiodism and identify which one contradicts the established understanding of this phenomenon.

5. **Determine the Incorrect Statement**:
- If a statement claims that the site of perception of light is something other than leaves (e.g., "cutlet dense and embryo"), it would be incorrect, as the leaves are indeed the site of perception.

### Conclusion:
The incorrect statement regarding photoperiodism in plants is the one that states the site of perception of light is "cutlet dense and embryo," as this is not true; the correct site is the leaves.

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