Topic 3 - ABO Blood Group Inheritance

Question 1

What is it called when two dominant alleles can be expressed together in the same individual?

Answer 1

Codominance

Codominance occurs when both alleles contribute equally to the phenotype.

Question 2

What do we call a situation where three or more alleles can be present at the same locus?

Answer 2

Multiple alleles

Multiple alleles refer to the presence of more than two allele forms for a particular gene.

Question 3

What are the alleles involved in the ABO blood group system?

Answer 3

A, B, and O

The ABO blood group system has three main alleles that determine blood type.

Question 4

What blood type results from the combination of A and B alleles?

Answer 4

Type AB

Type AB blood is an example of codominance where both alleles are expressed.

Question 5

What is the phenotype for the combination of A and O alleles?

Answer 5

Type A

The A allele is dominant over the O allele, resulting in Type A blood.

Question 6

What phenotype occurs with the combination of B and B alleles?

Answer 6

Type B

Individuals with two B alleles will express Type B blood.

Question 7

What is the phenotype for the combination of O and O alleles?

Answer 7

Type O

Type O blood results from the presence of two O alleles, which are recessive.

Question 8

What can be said about the rarity of Type O blood compared to other blood types?

Answer 8

Type O blood is significantly more rare

This is due to the dominance of A and B alleles in the population.

Question 9

Fill in the blank: The O allele is __________.

Answer 9

Recessive

The recessive nature of the O allele means it only expresses when paired with another O allele.