Question

1. What are the possible genotypes of the offspring made from a parent with homozygous Type A blood andanother with heterozygous Type B blood?2. What are the chances of getting a baby with type A blood from a parent with Type AB blood and anotherwith Type O blood?3. Which two parent genotypes give the possibility of having offspring with Type A, Type B, Type O, or Type ABblood?27

Answer 1

INTRODUCTION

The blood group is given by three different alleles: A, B and O; where A and B have the same dominance and at the same time, both are dominant over the O allele. Therefore, the possible combinations of alleles and the resulting blood groups would be:

A/A: Blood Type A

A/B: Blood Type AB

B/B: Blood Type B

A/O: Blood Type A

B/O: Blood Type B

O/O: Blood Type O

QUESTIONS

1. Now we can do the punnet square for the cross between a homozygous type A individual (A/A) and a heterozygous type B individual (B/O); It should be noted that the second individual cannot have a B/B genotype because he would be homozygous:

2. Using the same information from the introduction and following the example of question 1 we can make another punnet square to answer the second question:

Parent 1 (Blood type AB) x Parent 2 (Blood type OO)

3. To answer question 3 we only have to cross two individuals heterozygous for blood types A and B (A/O and B/O) having a 25% chance of each blood type in the offspring: