Question

Rh factor is present in
A) All vertebrates
B) All mammals
C) All reptiles
D) Man and Rhesus monkey only

Answer 1

Rh factor was discovered by K Landsteiner and A S Wiener (1940) from rabbits immunized with the blood of monkey Macaco, rhesus.

Complete answer:
Rh factor, also known as the Rhesus factor, is a type of protein that is found on the outside of red blood cells. This protein is genetically inherited, i.e., passed down from your parents. If the blood has the protein, it is said to be Rh-positive and if the blood lacks the protein, it is said to be Rh-negative. The Rh factor is among the 30 human blood group systems and was first discovered by Landsteiner and Weiner during immunization of a rabbit with the blood of Rhesus monkey, hence the name Rh factor. The retrieved antibodies also agglutinated blood of some caucasian people, which led to the discovery of the presence of the Rh blood group system in humans and Rhesus monkeys. Rhesus factor is an important characteristic of blood cells.

Thus, the correct answer is option (D) Man and Rhesus monkey only.

Note: It should be noted that the Rhesus factor can affect your pregnancy. It can cause complications during pregnancy if an Rh-negative mother carries an Rh-positive child. Rh incompatibility occurs when a woman who is Rh-negative becomes pregnant with a baby with Rh-positive blood. The woman’s immune system reacts and creates Rh antibodies. These antibodies help drive an immune system attack against the baby, which the mother’s body views as a foreign material.