Sexual reproduction in lichen is by

Options

A. Ascospore
B. Sporangiospore
C. Basidiospore
D. Soredia

Answer

To answer the question about how sexual reproduction occurs in lichens, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Lichens**: Lichens are symbiotic associations between fungi and photosynthetic organisms (like algae or cyanobacteria). They can reproduce both sexually and asexually.

2. **Identifying Reproductive Structures**: In lichens, the reproductive structures can be categorized into sexual and asexual forms. The question specifically asks about sexual reproduction.

3. **Types of Spores**:
- **Ascospore**: This is produced by ascomycete fungi during sexual reproduction, but it is not the primary reproductive structure in lichens.
- **Sporangiospore**: This type of spore is typically associated with asexual reproduction and is not relevant to sexual reproduction in lichens.
- **Basidiospore**: This is produced by basidiomycete fungi and is a form of sexual reproduction. It is relevant to lichens that have a basidiomycete partner.
- **Soredia**: These are a means of vegetative reproduction, not sexual reproduction.

4. **Conclusion**: Given the options and the definitions, the correct answer for sexual reproduction in lichens is **Basidiospore**.

### Final Answer:
The sexual reproduction in lichen is by **Basidiospore**.

---