Codominance

The video explains codominance, where both alleles are expressed in the phenotype, unlike monohybrid crosses where one allele is dominant. Examples include speckled chickens and blood groups. Blood group genetics are detailed, showing how IA and IB are codominant, while IO is recessive. A Punnett square is used to illustrate possible offspring genotypes from parental alleles.

What is the main difference between a monohybrid cross and codominance?

• Monohybrid cross involves two characteristics, codominance involves one.

• In a monohybrid cross, both alleles are expressed equally.

• Monohybrid cross results in a mixture of traits, while codominance does not.

• Codominance results in a mixture of traits, while monohybrid cross does not.

Which of the following blood groups is a result of codominance?

• Blood group A

• Blood group AB

• Blood group O

• Blood group B

How many alleles are involved in determining human blood groups?

• Five

• Four

• Three

• Two

If a child has blood group O, what can be inferred about the parents' alleles?

• Both parents must have at least one IO allele.

• One parent must have IA and the other IB allele.

• Both parents must have at least one IA allele.

• Both parents must have at least one IB allele.

In a Punnett square, if one parent has IAIO and the other has IBIO, which blood group is not possible for their offspring?

• Blood group A

• Blood group B

• Blood group AB

• Blood group O