For practice, let's work with blood groups. Three alleles exist for human blood types. They were not numbered, but instead marked with the letters for A, B and O. The labeling convention is : IA, IB, and Ii. IA and IB are codominant alleles, whereas Ii is the recessive allele for type O. Humans are diploid; every individual carries only two alleles.

I think this is the complete question you were hoping to ask:

For practice, let's work with blood groups. Three alleles exist for human blood types. They were not numbered, but instead marked with the letters for A,B and O. The labelling convention is: IA, IB and Ii. IA and IB are codominant alleles, whereas Ii is the recessive type O. Humans are diploid; every individual carries only two alleles.

1.) List all possible blood group genotypes.

2.) How many kinds of homozygotes are there?

3.) How many kinds of heterozygotes are there?

4.) There are only 4 blood group phenotypes (A, B, AB and O). Based on the information given here , list the genotypes that produce each phenotype.

a.) type A  b.) type B   c.) type AB  d.) type O.

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1. All possible blood group genotypes are

  AA, AO, BB, BO, AB, OO

2. there are three kinds of homozygotes: AA, BB, OO

3. There are also three kinds of heterozygotes: AO, BO, AB

4. type A: AA, AO   type B: BB, BO  type AB: AB, type O: OO

Explanation:

The human blood group system is depicted in such a way that it is based on the presence or the absence of antigens A and B carried on the surface of the red blood cells. The pattern of inheritance of both A and B is usually in the codominant form. the blood types includes, A, B, O, AB.

1. All possible blood group genotypes are

  AA, AO, BB, BO, AB, OO

2. there are three kinds of homozygotes: AA, BB, OO

3. There are also three kinds of heterozygotes: AO, BO, AB

4. type A: AA, AO   type B: BB, BO  type AB: AB, type O: OO

regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation: