Question

c. multiple alleles
examine the chart below for blood types
blood type gene has three alleles;
a, b, and o (o is recessive)

1. cross a person that is homozygous for b blood with a person that is type o

genotype:
phenotype:

1. cross a person with o blood with a person that has ab blood

genotype:
phenotype:
alleles blood type
a+a = a
a+o = a
a+b = ab
b+b = b
b+o = b
o+o = o

Explanation:

Step1: Identify parent genotypes

Homozygous B: $I^B I^B$; Type O: $ii$

Step2: Set up Punnett Square (Q1)

	$I^B$	$I^B$
$i$	$I^B i$	$I^B i$

Step3: Determine Q1 genotype/phenotype

All offspring inherit $I^B i$.

Step4: Identify parent genotypes (Q2)

Type O: $ii$; Type AB: $I^A I^B$

Step5: Set up Punnett Square (Q2)

	$I^A$	$I^B$
$i$	$I^A i$	$I^B i$

Step6: Determine Q2 genotype/phenotype

Offspring have 2 genotypes: $I^A i$, $I^B i$.

Answer:

1. Genotype: All offspring are $I^B i$

Phenotype: All offspring have type B blood

1. Genotype: 50% $I^A i$, 50% $I^B i$

Phenotype: 50% type A blood, 50% type B blood