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

Options

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

Answer

To determine which statement is incorrect about the transport of gases, let's analyze each option step by step.

### Step-by-Step Solution:

1. **Analyze the First Statement**:
- The statement claims that 97% of O2 is transported by RBC (red blood cells).
- This is correct because most oxygen in the blood is indeed carried by hemoglobin within red blood cells in the form of oxyhemoglobin.

2. **Analyze the Second Statement**:
- This statement mentions that 3% of O2 is carried in a dissolved state in plasma.
- This is also correct. A small percentage of oxygen is dissolved in the plasma, while the majority is bound to hemoglobin.

3. **Analyze the Third Statement**:
- The statement indicates that 20 to 25% of CO2 is transported by RBC in the form of carbamino hemoglobin.
- This statement is correct as well. A significant portion of carbon dioxide is indeed transported in this form.

4. **Analyze the Fourth Statement**:
- This statement claims that about 70% of carbon dioxide is carried in a dissolved state in plasma.
- This statement is incorrect. In reality, about 70% of carbon dioxide is transported in the form of bicarbonate ions (HCO3-) in the plasma, not in a dissolved state.

### Conclusion:
- The incorrect statement among the options provided is the fourth one, which states that 70% of carbon dioxide is carried in a dissolved state in plasma.

### Final Answer:
The incorrect statement about the transport of gases is: "About 70% carbon dioxide is carried in dissolved state in plasma."

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