Which one is a living fossil ?

Options

A. Pinus
B. Gnetum
C. Ginkgo
D. Riccia.

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Living Fossil":**
- A living fossil refers to an organism that has remained relatively unchanged for millions of years and has living relatives that are no longer in existence (extinct).
- Example: If we have a plant that has existed for millions of years but its relatives have disappeared, that plant is considered a living fossil.

2. **Identifying Examples of Living Fossils:**
- We need to evaluate the options given: Pinus genetum, Ginkgo, Rixia.
- We will analyze each option to determine if it fits the definition of a living fossil.

3. **Evaluating Each Option:**
- **Pinus genetum:** This is a type of pine tree, but it does not fit the criteria of a living fossil as it has many existing relatives.
- **Ginkgo (Ginkgo biloba):** This tree is often cited as a classic example of a living fossil. It has existed for millions of years, and its relatives have largely gone extinct.
- **Rixia:** This plant does not have a significant history of being classified as a living fossil.

4. **Conclusion:**
- Among the options provided, Ginkgo biloba is the only organism that qualifies as a living fossil because it has survived for millions of years while its relatives have become extinct.

5. **Final Answer:**
- The correct answer is **Ginkgo (Ginkgo biloba)**.

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