Which substance destroy the harmful bacteria-

Options

A. Cerumin
B. Chyme
C. HCI
D. Secretin

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which substance is responsible for destroying harmful bacteria in the body.

2. **Analyzing the Options**:
- **Option 1: Cerumin**: This is a waxy substance secreted by ceruminous glands in the ear. It does not play a role in destroying harmful bacteria in the digestive system. Therefore, this option is incorrect.

- **Option 2: Chyme**: Chyme is a semi-fluid mass of partly digested food and gastric juices that is present in the stomach and intestines. While it is involved in digestion, it does not specifically destroy harmful bacteria. Thus, this option is also incorrect.

- **Option 3: Hydrochloric Acid (HCl)**: HCl is a strong acid secreted by the stomach lining. It has a very low pH (ranging from 1.5 to 3.5), which creates an acidic environment that is hostile to many harmful bacteria. It also denatures proteins and activates the enzyme pepsin, which aids in protein digestion. Therefore, this option is correct as it directly contributes to killing harmful bacteria.

- **Option 4: Secretin**: Secretin is a hormone produced in the duodenum that stimulates the pancreas and liver to secrete digestive juices. It does not have a direct role in destroying bacteria, making this option incorrect.

3. **Conclusion**: The substance that destroys harmful bacteria is Hydrochloric Acid (HCl), which is secreted by the stomach.

**Final Answer**: Hydrochloric Acid (HCl) is the substance that destroys harmful bacteria.

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