A sexual spore produced by a sac fungus is called :

Options

A. mycelium
B. conidium
C. ascospore
D. basidiospore

Explanation

To answer the question "A sexual spore produced by a sac fungus is called:", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of Spores**: We need to identify the different types of spores mentioned in the options: mycelium, conidium, ascospore, and basidiospore.

2. **Evaluate Mycelium**: Mycelium is not a type of spore. It is the vegetative part of the fungus, consisting of a mass of thread-like structures called hyphae. Therefore, mycelium is not the correct answer.

3. **Evaluate Conidium**: Conidia are asexual spores that are produced at the tips of hyphae. While they are indeed spores, they are not specifically associated with sac fungi. Thus, conidium is not the correct answer.

4. **Evaluate Ascospore**: Ascospores are the sexual spores produced by sac fungi (also known as ascomycetes). These spores are formed within a sac-like structure called an ascus. This makes ascospore the correct answer.

5. **Evaluate Basidiospore**: Basidiospores are produced by basidiomycetes, another group of fungi, and are formed on a structure called a basidium. Therefore, basidiospore is not the correct answer.

6. **Conclusion**: Based on the evaluations, the correct answer to the question is "ascospore," as it is the sexual spore produced by sac fungi.

### Final Answer:
The sexual spore produced by a sac fungus is called **ascospore**.

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