A man of blood type A married a woman of blood type B, they had a child of type AB. What does this mean in terms of genetics?

Question

Question

This question was previously asked in

RRB Group D 27 Sept 2022 Shift 3 Official Paper

The gene is dominant for blood group A and the gene is recessive for blood group B.
The gene for blood group B is dominant and the gene for blood group A is recessive.
The gene for blood type A and the gene for blood type B are both inactive.
Both the gene for blood type A and the gene for blood type B are dominant.

Answer 1

The correct answer is Both the gene for blood type A and the gene for blood type B are dominant.Key Points

The gene for blood group A is dominant and the gene for blood group B is recessive.
- This means that if a person has one gene for blood group A and one gene for blood group B, they will express the A phenotype because the A gene is dominant.
The child having blood type AB indicates that they inherited one gene for A from the father and one gene for B from the mother.
The A and B genes are codominant, which means that when they are both present, they both express themselves equally.
If both the gene for blood type A and the gene for blood type B are inactive, then the person would have blood type O, which is the absence of A and B antigens on the surface of red blood cells.
If both the gene for blood type A and the gene for blood type B are dominant, then a person with that genotype would have blood type AB, which is the codominant expression of both antigens.

Additional Information

Blood type is determined by the presence or absence of specific antigens on the surface of red blood cells.
The ABO blood group system is based on the presence or absence of two antigens: A and B.
A person with blood type A has the A antigen on their red blood cells, while a person with blood type B has the B antigen.
A person with blood type AB has both A and B antigens, while a person with blood type O has neither A nor B antigens.
The Rh factor is another antigen that can be present on red blood cells, and its presence or absence determines whether a person is Rh positive or Rh negative.