PATHOLOGY MCQ
GENETICS AND DISEASE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
multiple alleles.
|
|
|
a specific allele.
|
|
|
dozens of alleles.
|
|
|
2 codons.
|
Detailed explanation-1: -The A, B, AB and O blood group types in humans are determined by three alleles of a gene. The gene I, which determines the blood type, exists in three allelic forms, which are IA, IB and i.
Detailed explanation-2: -The ABO blood group antigens are encoded by one genetic locus, the ABO locus, which has three alternative (allelic) forms-A, B, and O. A child receives one of the three alleles from each parent, giving rise to six possible genotypes and four possible blood types (phenotypes).
Detailed explanation-3: -The human ABO blood group system exhibits codominance. The system consists of three alleles A, B, and O. Both A and B are dominant in relation to O, and therefore blood group A can have the genotype AA or AO.