Question

There are three different alleles of human ABO blood types that will produce how many genotypes and phenotypes respectively?
A) 4 and 6
B) 6 and 4
C) 6 and 6
D) 4 and 4

Answer 1

We all know that people have different kinds of blood groups. The discovery of different blood groups was made 100 years ago. It can be classified based on the presence and absence of antibodies and inherited antigenic receptors on the surface of red blood cells.

Complete answer:
Let’s clear the definition of genotypes and phenotypes first.
Genotypes: The traits that can be passed from parents to offspring are known as genotypes.
Phenotypes: the physical properties which are observable in an organism such as behavior, development, appearance, etc are known as phenotypes.
Now, coming back to the ABO blood group system, there are three individual alleles when paired determines the blood type and they are A, B, and i respectively. Each parent gives one allele to the progeny and those two alleles come together and decide the blood group of the progeny. In the following table, we can see that 6 genotypes can be produced from 3 individual alleles that are iAiA, iAiB, iAi, iBiB, iBi, and ii. Here the A and B alleles are dominant and express themselves over the i allele. So from the 6 genotypes, only 4 phenotypes that are blood groups can be seen such as A, B, O, and AB.

Alleles	iA	iB	iC
iA	iAiA	iAiB	iAi
iB	iAiB	iBiB	iBi
ii	iAi	iBi	ii

So the correct answer is B, 6 genotypes, and 4 phenotypes.

Note: What kind of blood type a progeny will have that majorly depend upon blood group alleles received by offspring. While transfusing blood to someone, the analysis of blood type has to be done otherwise it can cause blood clots due to the presence of antigen present in blood serum.