Identify whether the given statements are true or false for double circulation.
I. It checks the mixing of oxygenated and deoxygenated blood.
II. It carries only oxygenated blood.
Choose the correct option accordingly.

Options

A. I-False, II-False
B. I-True, II-True
C. II-False, I-True
D. I-True, II-False

Answer

To determine whether the given statements about double circulation are true or false, let's analyze each statement step by step.

### Step 1: Understand Double Circulation
Double circulation refers to the system in which blood passes through the heart twice during one complete circuit of the body. In humans, this involves two separate pathways: one for oxygenated blood and one for deoxygenated blood.

### Step 2: Analyze Statement I
**Statement I: It checks the mixing of oxygenated and deoxygenated blood.**

- In double circulation, the heart has a structure that prevents the mixing of oxygenated and deoxygenated blood. The right side of the heart receives deoxygenated blood from the body and pumps it to the lungs for oxygenation, while the left side receives oxygenated blood from the lungs and pumps it to the rest of the body.
- Therefore, this statement is **True**.

### Step 3: Analyze Statement II
**Statement II: It carries only oxygenated blood.**

- This statement is incorrect because double circulation involves both oxygenated and deoxygenated blood. The right side of the heart carries deoxygenated blood to the lungs, while the left side carries oxygenated blood to the body.
- Therefore, this statement is **False**.

### Conclusion
- **Statement I** is **True**.
- **Statement II** is **False**.

### Final Answer
The correct option is:
- Statement I: True
- Statement II: False

---