Which one of the following organisms is not an example of a unicellular eukaryote?

Options

A. Euglena
B. Gonyaulax
C. Amoeba
D. E. coli

Answer

To solve the question of which organism is not an example of a unicellular eukaryote, we can follow these steps:

### Step 1: Understand the Definitions
- **Eukaryotes** are organisms whose cells have a nucleus enclosed within membranes. They can be unicellular (single-celled) or multicellular (many cells).
- **Prokaryotes** are organisms whose cells do not have a nucleus. They are always unicellular.

### Step 2: Identify the Organisms
The options given are:
- A. Euglena
- B. Corneolax
- C. Amoeba
- D. E. coli

### Step 3: Classify Each Organism
- **Euglena**: This is a unicellular organism that belongs to the kingdom Protista and is a eukaryote.
- **Corneolax**: This is also a unicellular eukaryote, belonging to the kingdom Protista.
- **Amoeba**: This is another unicellular eukaryote, also classified under the kingdom Protista.
- **E. coli**: This is a bacterium, which is a prokaryote and belongs to the kingdom Monera.

### Step 4: Determine the Answer
Since E. coli is a prokaryote and not a eukaryote, it is the organism that is not an example of a unicellular eukaryote.

### Final Answer
The organism that is not an example of a unicellular eukaryote is **D. E. coli**.

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