Blood contains Red Blood Cells, White Blood Cells and Platelets. Red Blood Cells develop in bone marrow. They contain a protein called Haemoglobin which combines with oxygen to give blood–a red colour. Red Blood Cells circulate for around 120 days. They carry oxygen around the body and remove carbon dioxide from the body. The shape of a Red Blood Cell is a flat circle.
Where do Red Blood Cells Develop?
