To obtain virus-free, healthy plants from a diseased one by tissue culture technique, which part of the diseased plant will be taken ?

Options

A. (a) epidermis only
B. (b) apical meristem only
C. (c) palisade parenchyma
D. (d) both apical and axillary meristem

Answer

To obtain virus-free, healthy plants from a diseased one using tissue culture techniques, the following steps outline the process of identifying the appropriate part of the diseased plant to be taken:

### Step-by-Step Solution:

1. **Identify the Type of Tissue**:
- The first step is to understand that not all tissues in a plant are suitable for tissue culture, especially when the goal is to eliminate viruses.

2. **Focus on Meristematic Tissue**:
- The meristematic tissue is identified as the ideal choice. This tissue is undifferentiated, meaning it has not yet specialized into specific types of cells or organs.

3. **Characteristics of Meristematic Tissue**:
- Meristematic tissues have a high rate of cell division. This rapid division is crucial because it allows for the regeneration of healthy plant cells that can outpace the growth of any viruses present.

4. **Auxin Concentration**:
- Meristematic tissues also have a high concentration of auxins, which are phytohormones that promote cell elongation and division. Auxins can inhibit viral growth, making this tissue even more suitable for obtaining virus-free plants.

5. **Absence of Vascular Elements**:
- In meristematic tissues, vascular elements (which are pathways for virus movement) are absent. This means that the viruses cannot migrate through these tissues, further ensuring that the resulting plant will be virus-free.

6. **Selection of Specific Meristematic Parts**:
- Both apical (the tip of the plant) and axillary (the sides of the plant) meristems can be used to obtain virus-free plants. Thus, the correct choice would be to take either or both of these meristematic tissues.

7. **Conclusion**:
- Therefore, the correct answer to the question is that both apical and axillary meristematic tissues should be taken from the diseased plant for tissue culture to produce virus-free plants.

### Final Answer:
The part of the diseased plant that will be taken is **both apical and axillary meristematic tissues**.

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