The chemotherapeutic substance derived from living organismas that has an inhibitory effect on parasitic organisms is known as

Options

A. Exotoxin
B. Bactericide
C. Antibody
D. Antibiotic

Answer

To answer the question regarding the chemotherapeutic substance derived from living organisms that has an inhibitory effect on parasitic organisms, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a chemotherapeutic substance that is derived from living organisms and has an inhibitory effect on parasitic organisms.

2. **Analyzing the Options**:
- **Option 1: Exotoxin**: This is a toxin secreted by bacteria that can damage host cells. However, it is not a chemotherapeutic substance derived from living organisms aimed at inhibiting parasites.
- **Option 2: Bactericide**: This is a substance that kills bacteria but is not specifically derived from living organisms nor does it target parasitic organisms.
- **Option 3: Antibody**: Antibodies are protective proteins produced by the immune system against pathogens. While they play a role in fighting infections, they are not classified as chemotherapeutic substances derived from living organisms for the purpose of treating parasitic infections.
- **Option 4: Antibiotic**: Antibiotics are substances that can inhibit the growth of or kill bacteria and some protozoan parasites. They are derived from living organisms (like fungi and bacteria) and have a therapeutic effect against infections.

3. **Identifying the Correct Answer**: Based on the analysis, the correct answer is **Option 4: Antibiotic**, as it fits all criteria mentioned in the question.

### Final Answer:
The chemotherapeutic substance derived from living organisms that has an inhibitory effect on parasitic organisms is known as **Antibiotic**.

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