What is Rhesus factor

The Rhesus factor, or Rh factor, is an inherited genetic trait that can be passed down from parents to their children. It is a protein found on the surface of red blood cells and certain other body tissues in mammals such as humans. A person's Rh status can either be positive (+) if it contains the gene for expression of this marker, or negative (-) if they lack this gene. These two types are often referred to as being Rhesus-positive (Rh+) or Rhesus-negative (Rh-) respectively. 

People with Rh+ genes inherit them from both mother and father whereas those who have a 'negative' type only receive one copy of the gene from each parent: these people are said to be heterozygous while those with Rh+genotype carry two identical copies called homozygotes. Individuals who possess at least one rh(-) allele will also display characteristics usually associated with that genotype; weaker immune response against certain infections, higher risk for some metabolic diseases etcetera!

Functions of Rhesus factor

The Rhesus factor, also known as the Rh antigen or D antigen, is a protein located on the surface of red blood cells. 

It plays an important role in determining someone’s blood type and can cause medical issues if not affected properly. 

Rhesus factor functions by affecting how a person's immune system responds to certain antigens found on another person's red blood cells that have different types of Rhesus proteins or lack it altogether.

 If two people with incompatible Rhesus factors come into contact together, one partner may produce antibodies against their partners' antigens which could lead to immunological reactions such as hemolytic disease of the newborn (HDN). 

For this reason, pregnant women are routinely tested for compatibility between themselves and their fetuses so doctors can take preventative measures should any incompatibility be detected. 

This includes administering special treatments during pregnancies to reduce the risk of HDN occurring for babies whose mothers are Rh negative but carrying Rh positive infants.