Which of the following genera is associated with coralloid roots

Options

A. Cycas
B. Taxus
C. Pinus
D. Sequoia.

Answer

To solve the question "Which of the following genera is associated with coralloid roots?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question is asking for a specific genus that has a characteristic known as coralloid roots.

2. **Identify the Options**: The options provided are:
- Cyclus
- Texas
- Penis
- Scoia

3. **Research Coralloid Roots**: Coralloid roots are a type of root structure that is irregular and negatively geotropic (they grow against gravity). They are known for their coral-like appearance and lack of root hairs and root caps.

4. **Examine Each Option**:
- **Cyclus**: This genus is known to have coralloid roots. These roots form a symbiotic relationship with blue-green algae (cyanobacteria), such as Nostoc and Anabaena species.
- **Texas**: This does not refer to a genus associated with coralloid roots.
- **Penis**: This does not refer to a genus associated with coralloid roots.
- **Scoia**: This does not refer to a genus associated with coralloid roots.

5. **Conclusion**: Since Cyclus is the only genus listed that is associated with coralloid roots, it is the correct answer.

### Final Answer:
The correct answer is **Cyclus**.