Cellulosic cell wall, coenocytic mycelium, aquatic habitat are present in the members of fungi of class :

Options

A. Oomycetes
B. Zygomycetes
C. Ascomycetes
D. Basidiomycetes

Answer

To solve the question regarding which class of fungi has a cellulosic cell wall, coenocytic mycelium, and an aquatic habitat, we will analyze each of the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Mycelium**:
- Mycelium is the main body of fungi, composed of thread-like structures called hyphae.
- There are two types of mycelium: septate (with cross walls) and coenocytic (without cross walls).

**Hint**: Remember that coenocytic mycelium lacks septa, meaning it is a continuous network.

2. **Identifying the Classes of Fungi**:
- The options provided are Oomycetes, Zygomycetes, Ascomycetes, and Basidiomycetes.
- We need to determine which of these classes has a coenocytic mycelium and a cellulosic cell wall.

3. **Analyzing Oomycetes**:
- Oomycetes are known to have coenocytic mycelium, meaning their hyphae do not have septa.
- The cell wall of Oomycetes is made of cellulose, not chitin, which is common in other fungi.
- Oomycetes are typically found in aquatic environments.

**Hint**: Oomycetes are often referred to as "water molds" due to their aquatic habitats.

4. **Analyzing Zygomycetes**:
- Zygomycetes generally have septate mycelium and are terrestrial, not aquatic.
- Their cell wall is made of chitin, not cellulose.

**Hint**: Zygomycetes are commonly found in soil and decaying matter.

5. **Analyzing Ascomycetes and Basidiomycetes**:
- Both Ascomycetes and Basidiomycetes have septate mycelium.
- They also have chitin in their cell walls, and they are primarily terrestrial.

**Hint**: Both these classes are known for their complex fruiting bodies and are not aquatic.

6. **Conclusion**:
- Based on the analysis, the class of fungi that has a cellulosic cell wall, coenocytic mycelium, and an aquatic habitat is **Oomycetes**.

### Final Answer:
The correct class of fungi is **Oomycetes**.