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In a cross with a mother who carries the allele for hemophilia and a father who has normal blood clotting what would be the expected phenotypes of the offspring?

Respuesta :

1/4 carrier female, 1/4 regular female, 1/4 hemophiliac male, 1/4 regular male

Answer:

The correcet phenotype ratio would be 3 normal : 1 hemophilic (boy).

Explanation:

Hemophilia is the recessive X linked disease which means it express only when both X chromosomes are recessive For this disease in females and carrying only one recessive X chromosome for gene is consider as carrier of the disease, however in males there is only one X chromosome present so if its recessive they will have hemophilia disorder.

Offsprings of carrier mother (XcXC) and normal father (XCY) cross will form gametes Xx, XC and XC, Y will assort independently with each other and produce offspring genotypicaly XcXC (carrier female), XcY (hemophilic male), XCXC (normal female), XCY (normale male) 25% each.

One can not tell phenotypicaly that individual is carrier or not so phenotype of offsprings (male and female) will be 3 normal: 1 hemophilic or 75% normal offspring and 25% diseased.