Cell wall is absent in :

Options

A. Nostoc
B. Aspergillus
C. Funaria
D. Mycoplasma

Answer

To determine in which organism the cell wall is absent, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Analyze the first option: Nostoc**
- Nostoc is a genus of cyanobacteria. It is known to have a cell wall, although it is composed of non-cellulosic materials, specifically pseudo-mureins.
- **Conclusion**: Nostoc has a cell wall.

2. **Analyze the second option: Aspergillus**
- Aspergillus is a genus of fungi. Its cell wall is made up of polysaccharides, primarily beta-1,3-glucan and chitin, which provide structural support and rigidity.
- **Conclusion**: Aspergillus has a cell wall.

3. **Analyze the third option: Funerea**
- Funerea is a genus of fungi, and like other fungi, it possesses a cell wall that is made of chitin and other polysaccharides.
- **Conclusion**: Funerea has a cell wall.

4. **Analyze the fourth option: Mycoplasma**
- Mycoplasma is a genus of bacteria that is unique because it lacks a cell wall. Instead, it has a flexible cell membrane, which allows it to change shape and size.
- **Conclusion**: Mycoplasma does not have a cell wall.

### Final Answer:
The correct answer is **Mycoplasma**, as it is the only organism listed that lacks a cell wall.

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