The term explant refers:

Options

A. A plant part used for tissue culture
B. An unorganised mass of cells
C. A complete hybrid plant
D. A waste part of plant

Answer

### Step-by-Step Solution:

1. **Understanding the Term "Explant":**
- The term "explant" is derived from two parts: "ex" meaning from or out of, and "plant" referring to a portion of a plant.
- An explant is a piece of plant tissue that is taken from a plant for the purpose of tissue culture.

2. **Role of Explant in Tissue Culture:**
- Tissue culture is a technique used to grow new plants from small pieces of plant tissue (the explant).
- The explant can be any part of the plant, such as leaves, stems, or roots, and is used to regenerate a whole plant.

3. **Nutrient Medium:**
- For the explant to grow into a new plant, it is placed in a specific nutrient medium that provides the necessary nutrients and hormones required for growth and development.

4. **Micropropagation:**
- This technique allows for the rapid multiplication of plants. A small piece of the plant (explant) can lead to thousands of new plants through micropropagation.

5. **Conclusion:**
- Therefore, the term "explant" refers to a portion of a plant taken for tissue culture to regenerate a new plant.