What type of cell is responsible for carrying oxygen throughout the body? 

Red blood cells, also known as erythrocytes, are responsible for carrying oxygen throughout the body. These cells contain a protein called hemoglobin, which binds to oxygen and transports it from the lungs to the body's tissues and organs. Once the hemoglobin releases oxygen to the cells, it binds with carbon dioxide produced by the cells and transports it back to the lungs to be exhaled. Therefore, red blood cells play a critical role in the respiratory system and are responsible for delivering oxygen to all parts of the body.