Standard Science Primary 5 Systems

Which of the following correctly describes the blood flowing from the lungs to the heart?

A It is rich in carbon dioxide.
B It is rich in oxygen.
C It contains no waste materials.
D It flows through the windpipe.
Show Worked Solution

Worked Solution

Step 1: Gas exchange occurs in the lungs. Step 2: Blood picks up oxygen and drops off carbon dioxide. Step 3: Blood returning to the heart from the lungs is therefore oxygen-rich.

Correct answer: It is rich in oxygen.

Want more questions like this? Superholic Lab has 10,000+ MOE-aligned questions with full worked solutions.

Start Free Trial — 7 Days Free