`"_____________"` ml of oxygen is transported per 100 ml of blood.

Answer

To solve the question, we need to determine how much oxygen is transported in 100 ml of blood.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks how much oxygen (in ml) is transported per 100 ml of blood.

2. **Knowing the Value**: From biological studies, it is known that approximately 5 ml of oxygen is transported per 100 ml of blood.

3. **Final Answer**: Therefore, the answer to the question is **5 ml** of oxygen is transported per 100 ml of blood.