The first antibiotic called penicillin was extracted from:

Options

A. a bacterium
B. a protozoan
C. a fungus
D. an alga

Answer

**Step-by-Step Solution:**

1. **Understanding Penicillin**: Penicillin is known as the first antibiotic discovered and is crucial in treating bacterial infections.

2. **Identifying the Source**: The source of penicillin is important. It is derived from a specific type of organism.

3. **Genus of the Organism**: Penicillin is obtained from a fungus that belongs to the genus *Penicillium*.

4. **Historical Context**: The discovery of penicillin was made by Alexander Fleming, who found it accidentally while working with bacteria.

5. **Impact of Penicillin**: The antibiotic had a significant impact during World War II, helping to treat wounded soldiers effectively.

6. **Conclusion**: Based on the information, the first antibiotic, penicillin, was extracted from a fungus.

**Final Answer**: Penicillin was extracted from a fungus.

---