Which unicellular photosynthetic eukaryote lacks cell wall?

Options

A. Mycoplasma
B. Amoeba
C. Euglena
D. Slime mould

Answer

To solve the question "Which unicellular photosynthetic eukaryote lacks cell wall?", we can follow these steps:

### Step 1: Understand the Question
We need to identify a unicellular organism that is both photosynthetic and a eukaryote, while also lacking a cell wall.

### Step 2: Analyze the Options
The options provided are:
- Mycoplasma
- Amoeba
- Euglena
- Slime mould

### Step 3: Evaluate Each Option
1. **Mycoplasma**:
- Mycoplasma is a prokaryote, not a eukaryote. Although it lacks a cell wall, it does not fit the criteria of being a eukaryote.

2. **Amoeba**:
- Amoeba is a eukaryote, but it is not photosynthetic. It does not perform photosynthesis and typically has a flexible cell membrane rather than a rigid cell wall.

3. **Euglena**:
- Euglena is a unicellular eukaryote that is capable of photosynthesis. It has chloroplasts that allow it to perform photosynthesis, and it lacks a cell wall, having instead a flexible pellicle.

4. **Slime Mould**:
- Slime moulds are eukaryotic organisms that do have a cell wall, typically made of cellulose, and they are not primarily photosynthetic.

### Step 4: Identify the Correct Answer
Based on the evaluations:
- Mycoplasma is a prokaryote.
- Amoeba is not photosynthetic.
- Slime mould has a cell wall.
- Euglena is the only organism that is a unicellular, photosynthetic eukaryote that lacks a cell wall.

Thus, the correct answer is **Euglena**.

### Final Answer
The unicellular photosynthetic eukaryote that lacks a cell wall is **Euglena**.

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