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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
- The young woman shown at right has albinismvery pale skin, white hair, and pale blue eyes. This phenotype is due to the absence of melanin, which imparts color to the skin, hair, and eyes. It typically is caused by a recessive allele. In the following situations, what are the probable genotypes of the father, the mother, and their children? a. Both parents have normal phenotypes; some of their children are albino and others are not. b. Both parents and all their children are albino. c. The mother is not albino, the father is albino, and one of their four children is albino.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 child with normal vision and blue eyes?arrow_forwardTay-Sachs disease is a recessive genetic disease. Two individuals, both of whom are heterozygous for a recessive allele that causes the disease have one child who does not have the disease. What is the probability that this child has the potential to pass the disease-causing allele on to the next generation? Tay-Sachs disease is a recessive genetic disease. Two individuals, both of whom are heterozygous for a recessive allele that causes the disease have one child who does not have the disease. What is the probability that this child has the potential to pass the disease-causing allele on to the next generation? 1/4 1/2 3/4 2/3arrow_forward
- Red-green colorblindness is inherited in an X-linked recessive pattern in humans. A colorblind man and a woman with normal vision have four children, and one of them is a colorblind male. Does the mother have to be a carrier in this case? (Yes or No) What is the probability of the next child in this family being both colorblind and male? No, 25% Yes, 25% No, 50% Yes, 50%arrow_forwardIn humans, the genes for colorblindness and hemophilia are both located on the X chromosome with no corresponding gene in the Y. These are both recessive alleles. If a man and a woman, both with normal vision, marry and have a colorblind son, draw the Punnet square that illustrates this. If the man dies and the woman remarries a colorblind man, draw a Punnet Square showing the type of children that could be expected from the second marriage. How many/what percentages of each could be expected.arrow_forwardA type of red-green colorblindness is inherited recessively on the X chromosome. A woman who is a carrier had children with a male that is not affected by the disease. Show your answers with the use of a Punnett square • What is the probability (% or likelihood) that a child is affected by the disease? • What is the probability (% or likelihood) that a son is a carrier? (Careful!) • Is there a chance that a girl of the couple is affected by the disease?arrow_forward
- The bald phenotype which is due to a dominant autosomal gene the expression of which is sex influenced can often be distinguished at a relatively early age. Red-green colorblindness is due to a recessive X-linked gene. A non-bald, red-green colorblind man marries a non-bald, normal visioned woman whose mother was bald and whose father was red-green colorblind. What is the probability of the following in the progeny? Bald girls Normal visioned progeny Bald, normal visioned boys? Red-green colorblind children Red-green colorblind trait among the daughters Bald phenotype among the sons?arrow_forwardRed-green color blindness is inherited as an X-linked recessive (Xc). If a color-blind man marries a woman who is heterozygous for normal vision, what would be the expected phenotypes of their children with reference to this character? In your answer, specify in your phenotype descriptions the gender of the children. (For example, don’t just say 75% of the children would be colorblind – you would instead say 100 % of the daughters would be colorblind and 50% of the sons would be colorblind. Note that this is not a correct answer; it is just to give you an idea of how to explain the correct phenotypes of the cross.)___arrow_forwardIn the following pedigree of an X-linked recessive trait, what is the likelihood a child will be affected for the following matings? 1 x 2 [___] 13 x 14 [_____] 2 x 14 [_______] 4 x 12. [_______]arrow_forward
- Albinism is a recessive disorder where there is a lack of melanin. Andrea and her husband Claude both have normal skin pigmentation. Andrea’s mother has the albino phenotype, but her father and her brother do not (normal pigmentation). Claude’s parents are both normal, but he has a sister who has the condition (is albino). Answer the following questions If Andrea and Claude are carriers for the albino allele, what is the probability that they have an albino child? If Andrea and Claude have a second child, what is the probability this child be normal (non-albino)? NOTE: Draw a punnet square or show your work.arrow_forwardRed-green color blindness is an X-linked recessive disorder. If Allison is heterozygous (a carrier), and her husband, Michael, is NOT colorblind. What is the chance that their male children will be colorblind? (Note: you are calculating the probability for their MALE children only, in other words if they have 1 male child, what is the probability that he will be born with the disease?) 0% 25% or 1/4 50% or 2/4 75% or 4/4 100% or 4/4arrow_forwardWhich of the following is indicated by roman numerals in a pedigree? a.Presence of the studied trait b.Generation c.Sex d.Marriage status Which of the following disorders in humans has an autosomal dominant inheritance pattern? a.Albinism b.Hemophilia c.Tay-Sachs disease d.Huntington’s disease For an X-linked recessive allele, what proportion of female offspring will be carriers in the cross of an affected father and a noncarrying mother? a.50 percent b.0 percent c.100 percentarrow_forward
- Human Biology (MindTap Course List)BiologyISBN:9781305112100Author:Cecie Starr, Beverly McMillanPublisher:Cengage LearningBiology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning