Red Blood Cells (RBCs) are crucial for oxygen transport throughout the body. They contain haemoglobin, a red-coloured protein that has a strong affinity for oxygen. Haemoglobin binds with oxygen in the lungs and releases it in the body's tissues. Plasma is the liquid part of blood that carries nutrients, hormones, and waste products. Platelets are involved in blood clotting to prevent excessive bleeding. White Blood Cells (WBCs) are part of the immune system, fighting infections and foreign invaders.