Nutrient medium is made semisolid by adding

Options

A. 2,4 D
B. agar agar
C. alfa alfa
D. yeast

Answer

**Step-by-Step Solution:**

1. **Understanding the Nutrient Medium**: A nutrient medium is a substance that provides essential nutrients for the growth of cells, tissues, or microorganisms in a controlled environment. It is crucial in various biological applications, including tissue culture.

2. **Properties of the Medium**: The medium can be in three states: liquid, solid, or semi-solid. A semi-solid medium has a jelly-like consistency, which is neither completely liquid nor completely solid. This property is important for supporting the growth of cells while allowing for some movement and diffusion of nutrients.

3. **Role of Agar-Agar**: Agar-agar is a gelatinous substance derived from red algae (seaweed) and is commonly used in microbiological and tissue culture media. It acts as a gelling agent that transforms the liquid medium into a semi-solid state.

4. **Why Agar-Agar is Used**: Agar-agar is preferred because it remains solid at higher temperatures and provides a stable environment for the growth of various organisms, including bacteria and fungi. It is also non-toxic to most cells, making it suitable for tissue culture.

5. **Conclusion**: Therefore, the nutrient medium is made semi-solid by adding agar-agar.

**Final Answer**: Nutrient medium is made semi-solid by adding **agar-agar**.

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