The smallest functional unit of kidney is
(a) Nephron
(b) Collecting tubule
(c) Glomerulus
(d) Bowman's capsule

Options

A. Nephron
B. Collecting tubule
C. Glomerulus
D. Bowman's capsule

Answer

To solve the question "The smallest functional unit of kidney is", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the smallest functional unit of the kidney. This requires knowledge about the structure and function of the kidney.

2. **Identify the Options**: The options provided are:
- (a) Nephron
- (b) Collecting tubule
- (c) Glomerulus
- (d) Bowman's capsule

3. **Define Each Option**:
- **Nephron**: The nephron is the basic structural and functional unit of the kidney. It is responsible for filtering blood and forming urine.
- **Collecting tubule**: This is part of the nephron where urine is collected from the distal convoluted tubule before it moves to the renal pelvis.
- **Glomerulus**: A network of capillaries located within the nephron that is involved in the filtration of blood.
- **Bowman's capsule**: A cup-shaped structure that surrounds the glomerulus and collects the filtrate from the blood.

4. **Analyze the Options**:
- The nephron is composed of several parts, including the glomerulus and Bowman's capsule.
- The collecting tubule is also a part of the nephron.
- Since the nephron itself is the smallest functional unit that encompasses all these components, it is the correct answer.

5. **Conclusion**: Based on the definitions and analysis, the smallest functional unit of the kidney is the nephron.

### Final Answer:
(a) Nephron

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