Blood Type Genetics and Inheritance

The video tutorial covers the concept of codominance in blood types, explaining the different alleles involved, such as IA, IB, and i, and their dominance relationships. It provides examples of genetic crosses to determine blood type phenotypes and genotypes, focusing on type A, B, AB, and O blood types. The tutorial includes step-by-step examples to help students understand how to calculate the percentage of offspring with specific blood types and genotypes.

What is codominance in the context of blood types?

• A situation where one allele completely masks another

• A situation where neither allele is expressed

• A situation where both alleles are equally expressed

• A situation where alleles blend to form an intermediate phenotype

Which of the following is a recessive allele for blood type?

• i

• IB

• IAIB

• IA

What blood type results from the combination of IA and IB alleles?

• Type A

• Type B

• Type AB

• Type O

In the first example, what percentage of offspring have type A blood?

• 100%

• 25%

• 50%

• 75%

In the first example, what percentage of offspring have type AB blood?

• 75%

• 50%

• 25%

• 100%

In the second example, what percentage of offspring have type O blood?

• 50%

• 25%

• 100%

• 75%

In the second example, what percentage of offspring have type A blood?

• 100%

• 50%

• 25%

• 75%

In the third example, what percentage of offspring have type A blood?

• 100%

• 25%

• 75%

• 50%

In the third example, what percentage of offspring have a heterozygous genotype?

• 100%

• 75%

• 50%

• 25%

Which genotype represents a heterozygous condition?

• IAIA

• IBIB

• ii

• IAi