Answer: Erythrocytes contain large amounts of the protein hemoglobin to which oxygen and carbon dioxide reversibly combine.
Explanation: Erythrocytes, or red blood cells, are responsible for circulating oxygen and other gases around the body. In order to carry out this function, they have a protein known as hemoglobin.
Hemoglobin is a protein that can easily bind with both oxygen and carbon dioxide. The binding between these gases and hemoglobin is reversible, meaning that hemoglobin can also discharge and release these gases after binding with them. This is important because hemoglobin helps red blood cells carry oxygen throughout the body and deliver them to body cells. In addition, hemoglobin also plays the role of carrying carbon dioxide produced by cells and delivering them to the lungs so that it can be exhaled.