Example of positive geotropism is

Options

A. Closing of flowers
B. Upwards growth of stem
C. Downward growth of root
D. Lateral growth of root.

Answer

**Step-by-Step Solution:**

1. **Understand Geotropism**: Geotropism refers to the growth response of plant parts to gravity. It is important to distinguish between the two types of geotropism: positive and negative.

2. **Identify Positive Geotropism**: Positive geotropism is the growth of plant parts in the direction of gravitational pull. This means that roots, which grow downward, are exhibiting positive geotropism.

3. **Review the Options**:
- **Option A**: Closing of flowers - This is not related to geotropism.
- **Option B**: Upward growth of stem - This is an example of negative geotropism, as it grows against gravity.
- **Option C**: Downward growth of root - This is an example of positive geotropism, as roots grow in the direction of gravity.
- **Option D**: Lateral growth of root - This does not specifically indicate a response to gravity.

4. **Select the Correct Answer**: Based on the definitions and analysis of the options, the correct answer is **Option C: Downward growth of root**.

5. **Conclusion**: The example of positive geotropism is the downward growth of roots, as they grow towards the gravitational pull.

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