Which one of the following is neither a prokaryote nor an eukaryote?
(a) T.M.V.
(b) E. coli
(c) Yeast
(d) Cyanobacteria

Options

A. T.M.V.
B. E. coli
C. Yeast
D. Cyanobacteria

Explanation

To solve the question "Which one of the following is neither a prokaryote nor an eukaryote?", we need to analyze each option provided:

1. **Understanding Prokaryotes and Eukaryotes**:
- Prokaryotes are simple, unicellular organisms that lack a nucleus and membrane-bound organelles. Examples include bacteria.
- Eukaryotes are more complex organisms that have a nucleus and membrane-bound organelles. Examples include fungi, plants, and animals.

2. **Analyzing the Options**:
- **(a) T.M.V. (Tobacco Mosaic Virus)**: This is a virus. Viruses are not classified as living organisms because they cannot carry out metabolic processes on their own and require a host to replicate. Therefore, they do not fit into the categories of prokaryotes or eukaryotes.
- **(b) E. coli**: This is a bacterium, which is a prokaryote.
- **(c) Yeast**: This is a fungus, which is a eukaryote.
- **(d) Cyanobacteria**: These are photosynthetic bacteria, which are also classified as prokaryotes.

3. **Conclusion**:
- The only option that is neither a prokaryote nor a eukaryote is **(a) T.M.V. (Tobacco Mosaic Virus)**.

Thus, the correct answer is **(a) T.M.V.**.