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A sex-influenced trait in humans affects the length of the index finger. A short allele is dominant in males and recessive in females. Heterozygous males have an index finger that is significantly shorter than the ring finger. The gene affecting index finger length is located on an autosome. A woman with short index fingers has children with a man who has normal index fingers. They produce five children in the following order: female, male, male, female, male. The oldest female offspring has one daughter with a man who has normal fingers. The youngest male among the five children has children with a woman with short index fingers; they have two sons. Draw the pedigree for this family. Indicate the
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Genetics: Analysis and Principles
- A gene that controls the ability to see red and green is located on the X chromosome but not on the Y chromosome. There is a recessive nonfunctional allele for this gene that can cause red-green color blindness if the person possessing it does not also have the dominant normal gene. Consider the case of a carrier mother who is heterozygous for the red-green vision gene and a father who has normal vision. Use XB = normal vision, Xb = color-blind vision. What is the chance the parents would have a color-blind boy? A color-blind girl? What about a girl or boy with normal vision? Redo the Punnett square for a carrier mother (XBXb) and a color-blind father (XbY). Do the chances of having color-blind children change? How?arrow_forwardRed-green color blindness is inherited as a sex-linked recessive trait. The gene is found on the X chromosome. How can a man with normal color vision father a daughter who is red-green color-blind? Group of answer choices The man is heterozygous for red-green color blindness. The woman with whom he mates is red-green color-blind. He can't (unless there is a mutation). The man's mother carries an allele for red-green color blindness, and the expression of the trait skipped a generation.arrow_forwardIn humans, blue eyes are inherited as a recessive autosomal trait and color blindness is an X-linked recessive trait. A woman with blue eyes and normal color vision (her father was colorblind) marries a man who has normal color vision. The man has brown eyes, but his mother had blue eyes. What is the probability that this couple will have a son with brown eyes? What is the probability that this couple will have a color blind son with blue eyes?arrow_forward
- In humans, blue eyes are inherited as a recessive autosomal trait and color blindness is an X-linked recessive trait. A woman with blue eyes and normal color vision (her father was colorblind) marries a man who has normal color vision. The man has brown eyes, but his mother had blue eyes. What is the probability that this couple will have a child with normal vision and blue eyes?arrow_forwardA man who is a dwarf due to achondroplasia and has normal vision marries a color-blind woman of normal height. The man's father was 6 feet tall, and both the woman's parents were of average height. Achondroplasia is autosomal dominant, and red-green color blindness is X-linked recessive. What are the possible genotypes and phenotypes of their children? What are the ratios for each?arrow_forwardA man who is a dwarf due to achondroplasia and has normal vision marries a color-blind woman of normal height. The man's father was 6 feet tall, and both the woman's parents were of average height. Achondroplasia is autosomal dominant, and red-green color blindness is X-linked recessive. What are the possible genotypes and phenotypes of their children? What are the ratios for each? For full credit, you must show all work.arrow_forward
- Huntington's disease is an inherited autosomal dominant disorder that can affect both men and women. Imagine a couple has had seven children, and later in life, the husband develops Huntington's disease. He is tested and it is discovered he is heterozygous for the disease allele, Hh. The wife is also genetically tested for the Huntington's disease allele, and her test results show she is unaffected, hh. What is the percent probability that the first child of this couple will have Huntington's disease? probability: % What is the percent probability that two of the seven children will have Huntington's disease? probability: %arrow_forwardIf a trait is X-linked, which of the following statements is true? Two recessive alleles are needed to express that trait. A female with one recessive allele will express that trait. A female can be a carrier, affected or unaffected. The trait is inherited from father to son. The gene is carried on the Y chromosome.arrow_forwardman who is a dwarf due to achondroplasia and has normal vision marries a color-blind woman of normal height. The man's father was 6 feet tall, and both the woman's parents were of average height. Achondroplasia is autosomal dominant, and red-green color blindness is X-linked recessive. What are the possible genotypes and phenotypes of their children? What are the ratios for each? you must show all work.arrow_forward
- A certain type of deafness in humans is inherited as an X-linked recessive trait. A man with this type of deafness married a normal woman, and they are expecting a child. They find out that they are distantly related. Part of the family tree is shown here.How would you advise the parents about the probability of their child being a deaf boy, a deaf girl, a normal boy, or a normal girl? Be sure to state any assumptions that you make.arrow_forwardHemophilia is a recessive sex-linked trait in humans. Sickle-cell anemia is a recessive trait on an autosome. A couple are both carriers of the sickle-cell trait. The man and woman are normal, but the woman is a carrier for hemophilia. How many of their male children would you expect to have both sickle-cell anemia and hemophilia? How many of their female children would have both conditions?arrow_forwardThe shape of a heliodor is an X-linked trait. Male heliodors inherit two X chromosomes, while the females inherit an X and a Y chromosome. The recessive allele codes for the common bell-shape while the dominant phenotype is a round shape . Hudson is a round male and has offspring with Heidi, a bell-shaped female. They already have one daughter, Hannah, who is shaped like her mother. There is [blank] % that their next child will also be bell-shaped female like Hannah.arrow_forward
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