Standard Science Primary 5 Systems

What is the main function of the air sacs in the lungs?

A To store digested food.
B To pump blood to the rest of the body.
C To protect the heart from injury.
D To allow for the exchange of gases.
Show Worked Solution

Worked Solution

Step 1: Air sacs (alveoli) are at the end of the respiratory system. Step 2: Their thin walls are surrounded by blood vessels. Step 3: This is where oxygen enters the blood and carbon dioxide leaves it.

Correct answer: To allow for the exchange of gases.

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

Start Free Trial — 7 Days Free