HEREDITY
SEX LINKAGE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Large quantities of male hormones are necessary in order for the allele carrying the disease to be expressed.
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Female fetuses that carry the allele for the disease die before birth.
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A female could get the disease only by having a mother who is a carrier and a father who has the disease. Since most males with the disease do not survive to reproductive age, this is an extremely unlikely event.
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A female could get the disease only by having parents who are both carriers of the disease. Because females cannot be carriers, this is an impossible event.
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Detailed explanation-1: -Which of the following is the best explanation for the observation that females rarely get the disease hemophilia? a female could get the disease only by having a mother who is a carrier and a father who has the disease.
Detailed explanation-2: -Males can only get an X chromosome from their mother whilst females get an X chromosome from both parents. As a result, females tend to show higher prevalence of X-linked dominant disorders because they have more of a chance to inherit a faulty X chromosome.
Detailed explanation-3: -Hemophilia is a sex-linked recessive disorder. The abnormal gene responsible for hemophilia is carried on the X chromosome. Males have one X chromosome and one Y chromosome.
Detailed explanation-4: -With each pregnancy, a woman who carries an altered gene for X-linked recessive has a 50 percent chance of having sons who are affected and a 50 percent chance of having daughters who carry one copy of the altered gene.