If one homozygous parent expresses the GTA glycosyltransferase and the other homozygous parent expresses the GTP glycosyltransferase,what is the probability of a child with a blood type of O?
A) 0%
B) 25%
C) 75%
D) 100%

Question

Quizplus · Accepted Answer

When the parents express the GTA and GTP glycosyltransferases, their genotype would be IAiIBi x IAiIBi. The Punnett square would look like this:

IA   i          IB    i
IA IAIAi     IBIAi
IAIAi           IBIAi
iIAIBi          iIBIB
iIAIBi          iIBIB

In this case, the probability of a child with blood type O (ii) would be 25% (2 out of 8). This is because both the IA and the IB alleles will dominate the i allele in the expression of the glycosyltransferases, producing either type A (IAIA or IAi) or type B (IBIB or IBi) blood in the offspring. The only way to get type O blood is when both parents contribute an i allele, which only happens in 2 out of 8 possible offspring combinations. Therefore, the probability is 25%.

If One Homozygous Parent Expresses the GTA Glycosyltransferase and the Other