List the components of blood. Mention their functions.

The components of blood and their functions are as follows:

1. Red blood cells or erythrocytes: Red blood cells contain haemoglobin. Red blood cells are responsible for the transportation of oxygen to all parts of the body.
2. White blood cells or leucocytes: White blood cells are larger than RBCs and are devoid of haemoglobin. These blood cells are the soldiers of the body and protect the body against invading micro-organisms.
3. Platelets: Platelets help in clotting of blood in the event of an injury.
4. Plasma: Plasma is the straw-coloured liquid constituent of blood that transports nutrients as well as metabolic waste products.