Which of the following statement is incorrect about the transport of gases ?

Options

A. About 97% of `O_(2)` is transported by RBCs in the blood.
B. About 3% of `O_(2)` is carried in dissolved state in the plasma
C. About 20-25% of `CO_(2)` is transported by RBCs.
D. About 70% carbon dioxide is carried in dissolved state in plasma.

Answer

To determine which statement is incorrect about the transport of gases, we need to analyze each option provided in the question. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Transport of Oxygen
- **Fact**: About 97% of oxygen (O2) is transported by red blood cells (RBCs) through the pigment hemoglobin.
- **Conclusion**: This statement is correct.

### Step 2: Understand the Transport of Oxygen in Plasma
- **Fact**: Approximately 2-3% of oxygen is transported in a dissolved state in the blood plasma.
- **Conclusion**: This statement is also correct.

### Step 3: Understand the Transport of Carbon Dioxide
- **Fact**: About 20-25% of carbon dioxide (CO2) is transported by red blood cells.
- **Conclusion**: This statement is correct as well.

### Step 4: Analyze the Transport of Carbon Dioxide
- **Fact**: The majority of CO2 (about 70%) is transported in the form of bicarbonate ions (HCO3-) in the blood, not in a dissolved state.
- **Conclusion**: If the statement claims that 70% of CO2 is carried in a dissolved state, this is incorrect.

### Step 5: Identify the Incorrect Statement
- Based on the analysis, the only incorrect statement is the one that claims that 70% of CO2 is carried in a dissolved state. The correct transport method for the majority of CO2 is as bicarbonate ions.

### Final Answer
- The incorrect statement is **Option D**, which claims that 70% CO2 is carried in a dissolved state.

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