Question

If two individuals with blood group 'AB' marry and have sufficiently large number of children, these children could be classified as 'A' blood group : 'AB' blood group: 'B' blood group in 1 : 2 : 1 ratio. Modem technique of protein electrophoresis reveals presence of both 'A' and 'B' type proteins in 'AB' blood group individuals. This is an example of ______.

Options

• Co-dominance

• Polygenic inheritance

• Criss-cross inheritance

• Complete dominance

Answer 1

Co-dominance

Explanation:

Both alleles of a gene pair in a heterozygote are completely expressed in co-dominance, with neither dominant nor recessive to the other. 

When alleles I^A and I^B are present in the same AB blood group, they produce their own form of sugar on the RBC surface.  As a result, it is a case of co-dominance.