Agar is obtained from

Options

A. Gracilaria
B. Laminaria
C. Gelidium
D. Both (1) & (3)

Answer

**Step-by-Step Solution:**

1. **Understanding Agar**: Agar is a gelling agent that is primarily used in microbiology as a solidifying agent for liquid culture media. It is a polysaccharide that is unbranched.

2. **Source of Agar**: Agar is obtained from the cell walls of certain types of algae. Specifically, it is derived from red algae.

3. **Identifying the Types of Algae**: The two main species of red algae from which agar is extracted are Gelidium and Gracilaria.

4. **Evaluating the Options**:
- **Option 1: Gracilaria** - This is a type of red algae, so it is a correct source of agar.
- **Option 2: Laminaria** - This is a type of brown algae and does not produce agar, so it is incorrect.
- **Option 3: Gelidium** - This is also a type of red algae, making it another correct source of agar.

5. **Conclusion**: Since both Gracilaria and Gelidium are correct sources of agar, the correct answer is that agar is obtained from both these types of red algae. Therefore, the correct answer is option 4, which states that both 1 (Gracilaria) and 3 (Gelidium) are correct.