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In humans, three alleles affect blood type. The A and B alleles are codominant and the O allele is recessive.
Which of the following answer choices is true?

CORRECT (SELECTED)
The A and B alleles are codominant because both alleles are simultaneously expressed in the heterozygote.

This is true because it would result in the AB blood type, a codominant genotype that results in the codominant phenotype of both A and B antigens simultaneously present on AB red blood cells.

CORRECT (SELECTED)
Human blood type is an example of multiple allele inheritance.

Multiple allele inheritance occurs when a gene is controlled by more than two alleles. The ABO blood type system involves three alleles, two of which will be inherited by the diploid offspring.

Respuesta :

marianaegarciaperedo

ABO Blood type is coded by a triallelic gene expressing both codominance and complete dominance. IA and IB are dominant over i allele. IA and IB are codominant to each other.

What is the ABO blood type?

The ABO blood type refers to the type of blood of each person.

Blood type is determined by a triallelic gene, meaning that it follows a multiple allele inheritance pattern.

Depending on the allele combination, the inheritance pattern can be either codominance or complete dominance.

Let us analyze this information.

→ The gene that codes for blood type is I.

→ Three alleles are involved in blood type determination,

  • IA,
  • IB,
  • i

⇒ IA and IB alleles are dominant over i, meaning that in heterozygous genotype, only the I dominant allele will be expressed.

⇒ IA and IB are codominant, meaning that in heterozygous individuals, both alleles -IA and IB- will be simultaneoulsy expressed.

     Genotypes              Phenotypes                 Antigens            

IAIA (Homozygous)      A blood type               A type of antigens

IAi (Heterozygous)       A blood type               A type of antigens

IBIB (Homozygous)      B blood type               B type of antigens

IBi (Homozygous)         B blood type              B type of antigens

ii (Homozygous)            0 blood type             no antigen

IAIB (Heterozygous)     AB blood type           A and B antigens

Options

  • The A and B alleles are codominant because both alleles are simultaneously expressed in the heterozygote ⇒ CORRECT

In codominance both alleles are expressed in the phenotype. People carrying IA and IB alelles will express the AB blood type.

  • Human blood type is an example of multiple allele inheritance ⇒ CORRECT

Multiple allele inheritance refers to how a trait is coded concerning allele combination. When more that two alleles are involved in a trait expression, we refer to multiple allele inheritance.

You can learn more about ABO blood type at

https://brainly.com/question/27757703

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