GENETICS AND EVOLUTION
INHERITANCE AND VARIATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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All sons will have hemophilia
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all daughters will have hemophilia
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50% of daughters and 50% of sons have hemophilia
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100% of sons have hemophilia and 100% of daughters are carriers
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Detailed explanation-1: -Thus the correct answer is (D) 50% sons will have haemophilia. Note: Haemophilia is X recessive linked gene disorder. A carrier mother has 50% chance of transferring the disease to her daughter. An affected male will pass on the genes to the daughters.
Detailed explanation-2: -So, the correct answer is ‘50% sons will have haemophilia’.
Detailed explanation-3: -A baby girl will inherit an X chromosome with a dominant gene for normal blood clotting from her father. So the daughter will not have hemophilia. A daughter will get either her mother’s X chromosome with the hemophilia gene or her mother’s X chromosome with the normal gene for clotting.
Detailed explanation-4: -In other words, a woman who inherits a faulty X chromosome and abnormal factor gene will carry hemophilia. They may not have symptoms, but they can pass the condition on to their children. There’s a 50% chance that any children they have-boys or girls-will inherit hemophilia.