Question

__________ carries the carbon dioxide to the alveoli in the lungs.

Answer 1

Alveoli:

1. Alveoli are the tiny air sacs present in the lungs where the exchange of gases takes place.
2. The walls of the alveolus are very thin, so the molecules of gases can easily pass through it.
3. Along with it, each alveolus has a very complex, thin blood capillary network through which gases can come in and out.
4. Thus, oxygen diffuses into the blood from the alveoli and carbon diffuses out from the blood capillaries into the alveolus.

Final answer:
Blood capillaries carry the carbon dioxide to the alveoli in the lungs.