Select the incorrect match.

Options

A. Conducting part- It extends from the external nostrils upto the terminal bronchioles.
B. Functional residual capacity - Volume of air that remains in the lungs after a normal expiration.
C. Carbonic anhydrase enzyme - It is found in a very high concentration in the plasma.
D. Pneumotaxic center present in medulla

Answer

To solve the question of selecting the incorrect match, we will analyze each statement provided in the question step by step.

### Step 1: Analyze the first statement
- **Statement**: The conducting part extends from the external nostrils up to the terminal bronchioles.
- **Analysis**: This statement is correct. The conducting part of the respiratory system includes structures that transport air to the lungs, starting from the nasal cavity (external nostrils) and extending down to the terminal bronchioles. Its functions include humidifying, warming the air, and filtering out particles.

### Step 2: Analyze the second statement
- **Statement**: FRC (Functional Residual Capacity) is the volume of air that remains in the lung after normal expiration.
- **Analysis**: This statement is also correct. FRC is indeed the volume of air remaining in the lungs after a normal exhalation, which includes the residual volume and the expiratory reserve volume.

### Step 3: Analyze the third statement
- **Statement**: Carbonic anhydrase enzyme is found in very high concentration in the plasma.
- **Analysis**: This statement is incorrect. Carbonic anhydrase is primarily found in red blood cells (RBCs) in high concentrations, while its concentration in plasma is relatively low. This enzyme plays a crucial role in the conversion of carbon dioxide and water into carbonic acid.

### Step 4: Analyze the fourth statement
- **Statement**: The pneumotactic center is present in the medulla.
- **Analysis**: This statement is also incorrect. The pneumotactic center is located in the pons, not the medulla. The medulla contains the respiratory rhythm center, which is regulated by signals from the pneumotactic center.

### Conclusion
- The incorrect matches are found in statements three and four. Therefore, the answer to the question of selecting the incorrect match is that both statements three and four are incorrect.