Agar-agar, an important solidifying agent used in culture medium, is obtained from

Options

A. red algae
B. green algae
C. kelps
D. yellow algae

Answer

**Step-by-Step Solution:**

1. **Understanding Agar-Agar**:
- Agar-agar is a polysaccharide, which means it is a carbohydrate made up of multiple sugar molecules. It is commonly used as a solidifying agent in culture media for microbiological work.

2. **Identifying the Source**:
- Agar-agar is primarily obtained from certain types of algae. The question asks for the specific type of algae from which agar-agar is derived.

3. **Analyzing the Options**:
- The options provided are:
- A) Red algae
- B) Green algae
- C) Calves (which is not an algae)
- D) Yellow algae
- We need to determine which of these options is correct.

4. **Correct Identification**:
- Agar-agar is specifically extracted from red algae, which belong to the family Rhodophyceae. This is the key information needed to answer the question.

5. **Examples of Red Algae**:
- Some examples of red algae that are sources of agar-agar include species like Gelidium and Gracilaria. These species have cell walls that contain agar-agar.

6. **Conclusion**:
- Based on the information analyzed, the correct answer to the question is **A) Red algae**.

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