Red blood cells are specialized cells that have many adaptations which help them to transport oxygen efficiently in the body. 1. Firstly, red blood cells have haemoglobin protein that can bind to oxygen (acts as a carrier) and then transport it to the different parts of the body in the form of oxyhemoglobin. When the tissues need oxygen, the oxygen would dissociate from haemoglobin, and then it will be released into those tissues. 2. Red blood cells don’t have any nucleus due to which it is easier for them to have more space haemoglobin proteins and then for binding more oxygen. 3. They have thin cell membranes which increase the rate of diffusion of oxygen gas into and out of the cell. Also, the oxygen has to just diffuse to a shorter distance; hence, this process becomes more efficient with thin membranes. 4. Also, they have a biconcave shape which increases the surface area to volume ratio that again makes sure there is rapid diffusion happening. 5. Red blood cells are small cells, so they can pass easily through the narrow blood vessels, without getting stuck in them. This ensures a smooth flow of blood in the blood vessels. To wrap up: 