An explant is

Options

A. dead plant
B. part of the plant
C. part of the plant used in tissue culture
D. part of the plant that expresses a specific gene.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Term "Explant":**
- An explant refers to a piece of plant tissue that is excised from a plant and used for tissue culture.

2. **Identifying Characteristics of Explants:**
- Explants have the ability to regenerate into a whole plant. This property is known as totipotency, which means that a single cell or a small group of cells can develop into an entire organism.

3. **Explants in Tissue Culture:**
- In tissue culture, explants are placed in a nutrient medium under sterile conditions to promote growth and development into a new plant.

4. **Evaluating the Options:**
- **Option A:** Dead plant - Incorrect, as explants must be living tissue.
- **Option B:** Part of plant - This is too vague and not specific enough to be correct.
- **Option C:** Part of plant used in tissue culture - Correct, as this specifically describes the role of explants.
- **Option D:** Part of plant that expresses a specific gene - Incorrect, as this does not define an explant.

5. **Conclusion:**
- The correct answer is **Option C: Part of plant used in tissue culture**, as it accurately describes what an explant is.

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