Which one of the following is a living fossil

Options

A. Spirogyra
B. Cycas
C. Moss
D. Saccharomyces

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an example of a "living fossil." A living fossil is a term used to describe a species that has remained relatively unchanged over a long period of geological time and has no close living relatives.

2. **Analyzing the Options**: The options provided are:
- Spirogyra
- Cycus
- Mose
- Sucharomyces

3. **Identifying Living Fossils**: Among the options, we need to identify which one is recognized as a living fossil.
- **Spirogyra**: This is a green algae and does not fit the definition of a living fossil.
- **Cycus**: This is a genus of cycads, which are known to have existed since the time of the dinosaurs and have not changed significantly over millions of years. Thus, Cycus is a living fossil.
- **Mose**: This is likely a misspelling of "moss," which also does not fit the criteria.
- **Sucharomyces**: This is a type of yeast and does not qualify as a living fossil.

4. **Conclusion**: Based on the analysis, the correct answer is **Cycus**. It is a living fossil because it has retained its characteristics over millions of years while other related species have become extinct.

5. **Final Answer**: The living fossil among the options is **Cycus**.

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