Fungi lacking crosswalls in the mycelium belong to Class

Options

A. Phycomycetes
B. Ascomycetes
C. Basidiomycetes
D. Deuteromycetes.

Answer

To answer the question "Fungi lacking crosswalls in the mycelium belong to Class," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of Fungi**: Fungi are made up of a network of filaments called hyphae, which can be divided into two types: those with crosswalls (septate) and those without (coenocytic or aseptate).

2. **Identify the Classes of Fungi**: The question provides four options:
- A) Phycomycetes
- B) Ascomycetes
- C) Basidiomycetes
- D) Deuteromycetes

3. **Analyze Each Class**:
- **Phycomycetes**: This class includes fungi that typically lack crosswalls in their mycelium. They are often referred to as coenocytic fungi.
- **Ascomycetes**: This class has septate hyphae, meaning they have crosswalls.
- **Basidiomycetes**: Similar to Ascomycetes, they also have septate hyphae.
- **Deuteromycetes**: This class is known for fungi that do not have a known sexual reproduction stage, but they also typically have septate hyphae.

4. **Conclusion**: Based on the analysis, the class of fungi that lacks crosswalls in the mycelium is **Phycomycetes**. However, it is important to note that the term "Phycomycetes" has been largely replaced by more specific classifications like Zygomycetes.

5. **Final Answer**: Therefore, the correct answer is **A) Phycomycetes**.