A marathon runner sprints across the finish line at the end of a race, pumping her arms into the air while lengthening the stride of her legs. Which two organ systems are primarily responsible for her movements in the race?

answer: cellular respiration takes in food and uses it to create atp, a chemical which the cell uses for energy. usually, this process uses oxygen, and is called aerobic respiration. it has four stages known as glycolysis, link reaction, the krebs cycle, and the electron transport chain.