In: Biology
Give the expected genotypic and phenotypic ratios for the following crosses for ABO blood types:
IAi x IBi =
IAIB x IAi
IAIB x IAIB
ii x IAi
IAIB x ii
Co-dominant allele determine human blood type. There are three different alleles for human bloos group, known as IA, IB, and i. The IA and IB alleles are codominant, while the i allele is recessive.
There are four blood groupsin humans: A, B, AB and O. A and B individuals can be homozygous (IAIA, or IBIB) or heterozygous ((IAi or IBi, respectively).
1) IAi X IBi
IBi |
|||
IB |
i |
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IAi |
IA |
IAIB AB blood group |
IAi A blood group |
i |
IBi B blood group |
ii O blood group |
Genotype ratio: 1 IAIB : 1 IAi : IBi: 1 ii
Phenotype Ratio: 1 AB : 1A: 1B :1 O
2) IAIB x IAi
IAi |
|||
IA |
i |
||
IAIB |
IA |
IAIA A blood group |
IAi A blood group |
IB |
IAIB AB blood group |
IBi B blood group |
Genotype ratio: 1 IAIA : 1 IAIB : IAi: 1 IBi
Phenotype Ratio: 2A: 1 AB : 1B
3) IAIB x IAIB
IAIB |
|||
IA |
IB |
||
IAIB |
IA |
IAIA A blood group |
IAIB AB blood group |
IB |
IAIB AB blood group |
IBIB B blood group |
Genotype ratio: 1 IAIA : 2 IAIB : 1 IBIB
Phenotype Ratio: 1A: 2 AB : 1B
4) ii x IAi
IAi |
|||
IA |
i |
||
ii |
i |
IAi A blood group |
ii O blood group |
i |
IAi A blood group |
ii O blood group |
Genotype ratio: 2 IAi : 2 ii
Phenotype Ratio: 2 A : 2O
5) IAIB x ii
ii |
|||
i |
i |
||
IAIB |
IA |
IAi A blood group |
IAi A blood group |
IB |
IBi B blood group |
IBi B blood group |
Genotype ratio: 2 IAi : 2 IBi
Phenotype Ratio: 2 A : 2B