Guided course 04:37X-Linked Recessive Disorder: Hemophilia InheritanceJason Amores Sumpter3163views34rank
Multiple ChoiceWild type fruit flies have red eyes. A white-eyed female fly is crossed with a red-eyed male fly. All of the females from the cross are red-eyed and all of the males, white-eyed. What type of inheritance pattern is this?3776views8rank
Multiple ChoiceWhen Thomas Hunt Morgan crossed red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?6008views7rank
Open QuestionThe following pedigree is for the X-linked-recessive trait for color blindness. Using XN for the normal allele and Xn for the color blindness allele, fill in the top half of the boxes/circles with the genotype. Also, fill in the bottom half of the boxes/circles with the phenotype (Normal vision or color blind). If it is impossible to know for certain a specific allele in the genotype, then place a '?' to represent the allele that is in question.2235views16rank
Multiple ChoiceWhat is the probability that a human male will inherit an X-linked recessive allele from his father? 896views
Multiple ChoiceWhich of the following results of Thomas Hunt Morgan's experiments with white-eyed mutant flies was unexpected in light of Mendelian genetics? 865views
Multiple ChoiceFor an X-linked trait, it is the contribution of __________ that determines whether a son will display the trait. 870views
Multiple ChoiceIf a woman is heterozygous for a recessive sex-linked allele and her husband has the dominant allele, which one of the following is true about the probabilities for their children? 1427views
Multiple ChoiceIn werewolves (hypothetically), the pointy ear allele (P) is dominant over the round ear allele (p). The gene for ear shape is on the X chromosome. (Sex determination in werewolves is the same as for "other" humans.) A certain female werewolf has pointy ears even though her father had round ears. What percentage of her sons will have round ears if she mates with a werewolf with round ears? 1414views1rank
Multiple ChoiceA woman is red-green color-blind. What can we conclude, if anything, about her father? 1081views
Multiple ChoiceA woman is a carrier for red-green color blindness, a sex-linked trait. Her husband is normal (not color-blind) for this trait. What are the chances that their newborn daughter will be red-green color-blind? 1517views
Multiple ChoiceDuchenne muscular dystrophy is caused by a sex-linked recessive allele. Its victims are almost invariably boys, who usually die before the age of 20. Why is this disorder almost never seen in girls? 1430views2rank
Multiple ChoiceHemophilia is an X-linked disorder. The daughter of a father with hemophilia and a carrier mother has a __________ probability of having hemophilia. 855views
Multiple ChoiceConsider a woman who is a carrier of a recessive X-linked allele for hemophilia. Which of the following possibilities could explain the presence of the hemophilia allele in her genotype? 876views
Multiple ChoiceIn a certain fish, fin rays (supporting structures for the fins) can be either bony or soft in adult fish. Sex linkage in a fish is similar to that in humans. What evidence would most strongly support the idea that the ray locus is on the X chromosome? 1184views1rank
Multiple ChoiceX-linked genes differ from Y-linked genes in which of the following ways? 1876views2rank
Multiple ChoiceWomen with X-linked disorders always pass the genes for the disorder on to ______. While men with X-linked disorders always pass the genes for the disorder on to _______.357views1rank
Textbook QuestionA woman is a carrier of the X-linked recessive color blindness gene. She has children with a man with normal color vision. Which of the following is true of their offspring? a. All the males will be color blind; b. All the females will be carriers; c. Half the females will be color blind; d. Half the males will be color blind.5405views
Textbook QuestionA fruit fly with a gray body and red eyes (genotype BbPp) is mated with a fly having a black body and purple eyes (genotype bbpp). What ratio of offspring would you expect if the body-color and eye-color genes are on different chromosomes (unlinked)? When this mating is actually carried out, most of the offspring look like the parents, but 3% have a gray body and purple eyes, and 3% have a black body and red eyes. Are these genes linked or unlinked? What is the recombination frequency?712views
Textbook QuestionA series of matings shows that the recombination frequency between the black-body gene and the gene for dumpy (shortened) wings is 36%. The recombination frequency between purple eyes and dumpy wings is 41%. What is the sequence of these three genes on the chromosome?761views
Textbook QuestionThe pedigree in the figure below illustrates the inheritance of a sex-linked recessive trait. What is the genotype of individual II-5? a. XHXH; b. XHXh; c. XhXh; d. XHY; e. XhY1542views
Textbook QuestionAs a genetic counselor, you advise couples about the possibility of genetic disease in their offspring. Today you met with an engaged couple, both of whom are phenotypically normal. The man, however, has a brother who died of Duchenne-type muscular dystrophy, an X-linked recessive condition. His fiancée, whose family has no history of the disease, is worried that the couple's sons or daughters might be afflicted. The sister of this man is planning to marry his fiancée's brother. How would you advise this second couple?551views
Textbook QuestionAs a genetic counselor, you advise couples about the possibility of genetic disease in their offspring. Today you met with an engaged couple, both of whom are phenotypically normal. The man, however, has a brother who died of Duchenne-type muscular dystrophy, an X-linked recessive condition. His fiancée, whose family has no history of the disease, is worried that the couple's sons or daughters might be afflicted. How would you advise this couple?566views
Textbook QuestionA couple are both phenotypically normal, but their son suffers from hemophilia, a sex-linked recessive disorder. What fraction of their children are likely to suffer from hemophilia? What fraction are likely to be carriers?866views
Textbook QuestionHeather was surprised to discover she suffered from red-green colorblindness. She told her biology professor, who said, 'Your father is colorblind, too, right?' How did her professor know this? Why did her professor not say the same thing to the colorblind males in the class?445views
Textbook QuestionRecall that hemophilia is an X-linked recessive disease. If a woman with hemophilia had children with a man without hemophilia, what is the chance that their first child will have the disease? What is the chance that their first child will be a carrier?854views