What are the following?

(a) Rh factor

(b) Universal donor

(c) Diapedesis

(a) Landsteiner, and Weiner discovered the presence of a protein on the surface of red blood cells of Rhesus species (common monkey) and also in the human beings. They named this protein as Rh Factor. Rh factor is found in 85% of the white population and 93% of Indian population.

(b) People belonging to blood group O have no antigen on the plasma membrane of their red blood cells. Their blood can be transfused to any other person because neither of the antibodies in the recipient's blood plasma would agglutinate these cells. Hence, they are called universal donor.

(c) White blood cells are amoeboid and can produce pseudopodia with which they can squeeze through the walls of the capillaries into the tissues by a process called diapedesis.