Apogeotropic roots forming an association with BGA are observed in

Options

A. Cycas
B. Pinus
C. Banyan
D. Peepal

Answer

To solve the question regarding apogeotropic roots forming an association with blue-green algae (BGA), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Apogeotropic Roots**:
- Apogeotropic roots are roots that grow in a direction opposite to the force of gravity. They are often short and branching.
- These roots are also known as coralloid roots due to their irregular, beady appearance.

**Hint**: Remember that apogeotropic roots do not grow downward like typical roots but instead grow upwards or horizontally.

2. **Identifying the Types of Roots**:
- There are two types of branching roots:
- Long branching geotropic roots (which grow downwards).
- Short branching apogeotropic roots (which grow upwards or horizontally).

**Hint**: Focus on the characteristics of the roots mentioned in the question—specifically, look for short, irregular roots.

3. **Association with Blue-Green Algae**:
- The question specifies that these apogeotropic roots form an association with blue-green algae (BGA), which is known for its role in nitrogen fixation.
- In certain plants, these roots host cyanobacteria that help in fixing atmospheric nitrogen.

**Hint**: Think about which plants are known for having symbiotic relationships with cyanobacteria.

4. **Analyzing the Options**:
- **Option 1: Cycus** - This is a gymnosperm known to have coralloid roots that associate with BGA for nitrogen fixation.
- **Option 2: Pinus** - This is a type of conifer that does not have apogeotropic roots associated with BGA.
- **Option 3: Banyan** - This is a type of fig tree and does not have the specific root type mentioned.
- **Option 4: Peepal** - This is also a fig tree and does not have the association with BGA.

**Hint**: Consider which of the options is a gymnosperm and has a known relationship with blue-green algae.

5. **Conclusion**:
- Based on the above analysis, the correct answer is **Cycus**. This plant has short branching apogeotropic roots that form an association with blue-green algae for nitrogen fixation.

**Final Answer**: **Cycus**