Final answer:
Erythrocytes have features such as hemoglobin and biconcave shape that directly contribute to the transport of oxygen. They can carry up to four oxygen molecules and have a large surface area for efficient gas exchange. Additionally, their ability to fold and stack allows oxygen delivery in narrow capillaries.
Step-by-step explanation:
Erythrocytes, also known as red blood cells, have several features directly related to the transport of oxygen. First, they contain hemoglobin, a metalloprotein composed of four subunits with a ring-like structure. Hemoglobin binds oxygen, allowing each erythrocyte to carry up to four oxygen molecules. Second, erythrocytes have a biconcave shape, which provides a greater surface area for gas exchange relative to their volume. This enables them to efficiently transport oxygen to the body's tissues. Finally, erythrocytes can fold and stack themselves in narrow capillaries, ensuring that oxygen can be delivered even in tight spaces.