GENETICS AND EVOLUTION
EVOLUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Each of their sons will have hemophilia.
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None of their daughters will have hemophilia.
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Their sons have a 25% chance of having hemophilia.
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There is a 50% chance that their daughters will have hemophilia.
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Detailed explanation-1: -Hemophilia is a sex-linked recessive trait. Which of the following describes the probability of hemophilia in the offspring of a man who does not have hemophilia and a woman whose father is a hemophiliac? None of their daughters will have hemophilia.
Detailed explanation-2: -If a mother is heterozygous (a carrier) for hemophilia and the father does not have hemophilia, each son has a 1 in 2 (50%) chance of getting his mother’s hemophilia allele and having hemophilia.
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: -a 25% (one in four) chance of having a son with hemophilia. a 25% chance of having a son with normal blood clotting. a 25% chance of having a daughter who is a carrier. a 25% chance of having a daughter who has hemophilia.
Detailed explanation-5: -Based on the Punnett square, there is a 50% probability that the children will have hemophilia. For the female offspring, the possible genotypes are XH, Xh X H, X h (carrier) and Xh, Xh X h, X h (hemophiliac). For the male offspring, the possible genotypes are XH, Y X H, Y (no disease) and Xh, Y X h, Y (hemophiliac).