Effect of unilateral irradiation can be eliminated by keeping the plant in a clinostat in

Options

A. Horizontal position
B. Vertical position
C. Horizontal position and rotating it.
D. Vertical position and rotating it.

Answer

To solve the question regarding the effect of unilateral irradiation and how it can be eliminated by using a clinostat, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Unilateral Irradiation**:
- Unilateral irradiation refers to the exposure of a plant to light from one side only. This can cause the plant to bend or grow towards the light source, a phenomenon known as phototropism.

2. **Recognize the Role of a Clinostat**:
- A clinostat is an apparatus designed to rotate a plant slowly, which helps in negating the effects of gravity and other directional stimuli, such as unilateral light.

3. **Determine the Position of the Plant**:
- To effectively eliminate the effect of unilateral irradiation, the plant should be placed in a position where it can receive uniform light exposure from all sides.

4. **Identify the Correct Position and Movement**:
- The clinostat should be set to a vertical position while it rotates. This rotation ensures that the plant does not receive light from just one side, thus minimizing the effect of unilateral irradiation.

5. **Conclusion**:
- Therefore, the correct answer to the question is that the effect of unilateral irradiation can be eliminated by keeping the plant in a **vertical position and rotating it** on a clinostat.

### Final Answer:
The correct option is **vertical position and rotating it**.

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