Coralloid roots of Cycas are

Options

A. Negatively geotropic
B. Positively geotropic
C. Positively phototropic
D. Negatively phototropic.

Answer

**Step-by-Step Solution:**

1. **Understanding Coralloid Roots**: Coralloid roots are specialized structures found in certain plants, such as Cycas. They are characterized by their unique shape and function.

2. **Defining Geotropism**: Geotropism refers to the growth of a plant in response to gravity. It can be classified as:
- **Positive Geotropism**: Growth towards the gravitational pull (e.g., roots growing downwards).
- **Negative Geotropism**: Growth away from the gravitational pull (e.g., some roots or shoots growing upwards).

3. **Analyzing the Options**: The question provides four options regarding the nature of coralloid roots:
- Negatively geotropic
- Positively geotropic
- Positively phototropic
- Negatively phototropic

4. **Identifying the Correct Response**:
- Coralloid roots of Cycas are known to grow away from the earth, which means they exhibit negative geotropism. Therefore, the first option, "negatively geotropic," is correct.
- The other options can be eliminated:
- **Positively geotropic**: Incorrect, as coralloid roots do not grow towards gravity.
- **Positively phototropic**: Incorrect, as this refers to growth towards light, which is not applicable here.
- **Negatively phototropic**: Incorrect, as this does not relate to the growth pattern of coralloid roots.

5. **Conclusion**: The coralloid roots of Cycas are negatively geotropic, meaning they grow away from the gravitational pull.

**Final Answer**: Coralloid roots of Cycas are negatively geotropic.

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