Final answer:
The respiratory system is responsible for gas exchange, bringing oxygen into the body and removing carbon dioxide.
Step-by-step explanation:
The system responsible for replacing oxygen in the blood and removing carbon dioxide is the respiratory system. This organ system works to bring oxygen into the body while expelling carbon dioxide and other waste gases into the atmosphere. The respiratory system involves the exchange of gases via respiration in two main steps.
Firstly, oxygen is inhaled into the lungs, and carbon dioxide is exhaled out of the body through the respiratory tract. Secondly, the circulatory system carries the oxygen from the lungs to body cells and collects carbon dioxide as a waste product from the cells to take back to the lungs.
The cardiovascular system works closely with the respiratory system in maintaining homeostasis by transporting gases throughout the body. Oxygen absorbed by the blood in the lungs is then distributed to cells for cellular respiration, which generates ATP, the energy currency of the cell.