what are paternal & maternal chromosomes? how are blood groups determined?

1) Maternal chromosomes are the chromosomes received from your mother and paternal ones are those  received from your father.

Every man has 23 sets of chromosomes. Each set of chromosome is called homologous chromosomes because they contain the genes coding for the same characteristics. One of the homologous chromosomes comes from the father (paternal) and their other comes from the mother (maternal) during fertilisation.

 

 

2) The blood types are determined by the presence or absence of certain antigens – substances that can trigger an immune response if they are foreign to the body. 

There are four major blood groups determined by the presence or absence of two antigens – A and B – on the surface of red blood cells:

• Group A – has only the A antigen on red cells (and B antibody in the plasma)
• Group B – has only the B antigen on red cells (and A antibody in the plasma)
• Group AB – has both A and B antigens on red cells (but neither A nor B antibody in the plasma)
• Group O – has neither A nor B antigens on red cells (but both A and B antibody are in the plasma)

In addition to the A and B antigens, there is a third antigen called the Rh factor, which can be either present (+) or absent ( – ), designated as Rh +ve or Rh –ve.