MICROANATOMY

Detailed explanation-1: -In humans, as in all mammals, the mature RBC lacks a nucleus. This allows the cell more room to store hemoglobin, the oxygen-binding protein, enabling the RBC to transport more oxygen. RBCs are also biconcave in shape; this shape increases their surface area for the diffusion of oxygen across their surfaces.

Detailed explanation-2: -The cell is flexible and assumes a bell shape as it passes through extremely small blood vessels. It is covered with a membrane composed of lipids and proteins, lacks a nucleus, and contains hemoglobin-a red iron-rich protein that binds oxygen.

Detailed explanation-3: -Mature mammalian red blood cells and platelets lack a nucleus whereas white blood cells contain a nucleus.

Detailed explanation-4: -Red blood cells are adapted for the transport of oxygen. They are small and flexible so they can fit through narrow vessels, have a bi-concave shape which maximises their surface area to absorb oxygen, have a thin membrane so gases easily diffuse through, and contain haemoglobin which binds to oxygen.