“Tissue culture'' means

Options

A. Cultivation of tissue in laboratory through formation of new cells
B. Introduction of new tissue in an animal body
C. A technique for maintaining fragments of cells alive after their removal from an organism
D. Maintaining tissue alive by immersing it partially in a nutrient fluid

Explanation

**Step-by-Step Solution:**

1. **Definition of Tissue Culture**: Tissue culture refers to a collection of techniques used to maintain or grow plant cells, tissues, or organs in a controlled environment outside of their natural setting.

2. **Conditions for Tissue Culture**: The process requires specific conditions, which are usually provided in a laboratory setting. This includes sterile environments and nutrient-rich media that support the growth of the cells or tissues.

3. **Purpose of Tissue Culture**: The main goal of tissue culture is to cultivate tissues in a laboratory to study their growth, development, and response to various treatments. This technique is widely used in plant propagation, genetic engineering, and research.

4. **Options Analysis**: Given the options provided:
- A) Cultivation of tissue in laboratory through formation of new cells.
- B) Introduction of new tissue in an animal body.
- C) A technique for maintaining fragments of cells alive after their removal from an organism.
- D) Maintaining tissue alive by immersing it partially in a nutrient fluid.

The most accurate definition of tissue culture aligns with option A, as it emphasizes the cultivation of tissue in a laboratory setting.

5. **Conclusion**: Therefore, the correct answer to the question "Tissue culture means" is option A: "Cultivation of tissue in laboratory through formation of new cells."

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