Which of the following is not a function of kidneys?

Options

A. Regulation of blood pressure
B. Removal of urea
C. Regulation of acidity of fluids
D. Secretion of antibiotics

Answer

**Step-by-Step Solution:**

1. **Understand the Functions of Kidneys**: The kidneys are vital organs that perform several important functions in the body, primarily related to excretion and homeostasis.

2. **Identify Key Functions of Kidneys**:
- **Excretion of Waste**: The kidneys filter out waste products from the blood, including urea, which is a byproduct of protein metabolism.
- **Regulation of Electrolytes**: They help maintain the balance of electrolytes such as sodium, potassium, and calcium.
- **Acid-Base Balance**: The kidneys regulate the pH of the blood by excreting hydrogen ions and reabsorbing bicarbonate.
- **Regulation of Blood Pressure**: They help control blood pressure by regulating the volume of blood (by adjusting water excretion) and releasing the enzyme renin.

3. **Analyze the Options Given**: The question asks which of the following is NOT a function of the kidneys. The options typically include:
- Regulation of blood pressure
- Removal of urea
- Regulation of acidity or fluids
- Secretion of antibiotics

4. **Evaluate Each Option**:
- **Regulation of Blood Pressure**: This is a function of the kidneys. (Incorrect option)
- **Removal of Urea**: This is also a function of the kidneys. (Incorrect option)
- **Regulation of Acidity or Fluids**: This is a function of the kidneys. (Incorrect option)
- **Secretion of Antibiotics**: This is NOT a function of the kidneys. (Correct option)

5. **Conclusion**: The correct answer is the option that states "secretion of antibiotics" as this is not a function performed by the kidneys.

**Final Answer**: Secretion of antibiotics.

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