The correct answer is A.) however C.) is cellular respiration or the function of the mitochondria. D.) is describing chloroplasts B.) is something concerning DNA and proteins synthesis
D prevents repeating. experiments have to be repeated to be reliable.
Answer:
The Cardiovascular System
Explanation:
The respiratory system draws air into the lungs. Oxygen diffuses through the walls of the alveoli and across the walls of the capillaries where it enteres the bloodstream. The oxygen molecules are picked up by red blood cells, which are pumped through the blood vessels by the action of the heart. As the red blood cells carrying oxygen pass through capillaries near the cells, oxygen diffuses into the cells.
