Concept explainers
Hemophilia is a blood-clotting disorder in humans that follows an X-linked recessive pattern of inheritance. A man with hemophilia and a woman without hemophilia have a daughter with hemophilia. If you let H represent the normal allele and h the hemophilia allele, what are the genotypes of the parents?
a. Mother is
b..Mother is
c. Mother is
d. Mother is
Want to see the full answer?
Check out a sample textbook solutionChapter 4 Solutions
Genetics: Analysis and Principles
- Tay–Sachs disease is caused by recessive alleles on anautosome. In which case(s) could two parents with anormal phenotype have a child with Tay–Sachs?a. Both parents are homozygous for a Tay–Sachs allele.b. Both parents are heterozygous for a Tay–Sachsallele.c. One parent is homozygous for a Tay–Sachs allele,and the other is heterozygous.arrow_forwardRed-green color blindness is inherited through an X-linked, recessive allele (b). Two parents, Fred and Ginger, have normal vision. They have two daughters, Takiyah and Kelly, who also have normal vision, and a color-blind son, David. 3. Daughter Kelly has a color-blind son, Kevin. Daughter Takiyah has five sons, all with normal vision. What are the genotypes of all the individuals? Show all your work! Fred Ginger David Takiyah Kelly Kevin Takiyah's five sons If Kelly marries a man with normal vision, what is the probability that she'll have a color-blind son? a color-blind daughter?arrow_forwardHemophilia is a sex-linked trait. A person with hemophilia is lacking certain proteins that are necessary for normal blood clotting. Hemophilia is caused by a recessive allele so use "N" for normal and "n" for hemophilia. Since hemophilia is sex-linked, remember a woman will have two alleles (NN or Nn or nn) but a man will have only one allele (N or n). A woman who is heterozygous (a carrier) for hemophilia marries a normal man: a.What are the genotypes of the parents? b.What is the probability that a male offspring will have hemophilia? c. What is the probability of having a hemophiliac female offspring?arrow_forward
- Hemophilia is a disease caused by a gene found on the X chromosome. Therefore, it is a sex-linked disease which is caused by the recessive allele. Suppose, a man with hemophilia marries a woman who is homozygous dominant for the trait, what is the chance of having children who are hemophiliacs? (XH = normal; Xh= hemophiliac) * a. 0% b. 75% c. 100% d. 25%arrow_forwardDuchenne muscular dystrophy is sex linked and usually affects only males. Victims of the disease become progressively weaker, starting early in life.a. What is the probability that a woman whose brother has Duchenne’s disease will have an affected child?b. If your mother’s brother (your uncle) had Duchenne’s disease, what is the probability that you have received the allele?c. If your father’s brother had the disease, what is the probability that you have received the allele?arrow_forwardHair texture is determined by gene c in an incomplete dominance inheritance pattern, where the heterozygous condition (c1c2) results in wavy hair. Hairline is controlled by gene H, where a widow's peak is dominant to a straight hairline. If a woman with curly hair and a straight hairline has a child with a man with a widow's peak and straight hair (his mom had a straight hairline), what is the chance they would have a kid that has exactly the same hair as mom? Draw the Punnett square and demonstrate the possible genotypes and phenotypes that could result from these two parents' mating.arrow_forward
- Albinism causes the skin, hair, or eyes to have little or no color. It is also associated with vision problems. Albinism results from an allele a that is recessive to the allele for normal melanin production. Maya has normal skin color, but her sister has albinism. Maya’s mother has albinism, and her father has normal skin color. a)What are the genotypes of Maya, her sister, her mother, and her father. b)If Maya’s parents have another child, what is the probability that this child will have albinism? Show the Punnett square you use to help in solving. c)If Maya marries a man with albinism, what is the probability that their first child will have albinism? Show the Punnett square you use to help in solving.arrow_forwardIn humans, the ABO blood type is under the control of autosomal multiple alleles. Color blindness is a recessive X-linked trait. If two parents who are both type A and have normal vision produce a son who is color-blind and is type O, what is the probability that their next child will be a female who has normal vision and is type O?arrow_forwardColour-blindness is the result of an X-linked recessive allele, Xc. The allele for normal eyesight is XC. (a) A woman with normal colour vision whose father was colour-blind marries a colour-blind man. Give the genotypes and phenotypes of their children. What ratio of their children can be expected to be colour-blind? (b) A man with normal colour vision whose father was colour-blind marries a woman carrier of the colour-blind allele. What is the likelihood that their children will be colour-blind? Carriers of the trait?arrow_forward
- In humans, the ABO blood type is under the control of autosomal multiple alleles. Color blindness is a recessive X-linked trait. If two parents who are both type A and have normal vision produce a son who is color blind and is type O, what is the probability that their next child will be a female who has normal vision and is type O?arrow_forwardIchthyosis is a rare X-linked recessive disorder that is characterized by scaling of the skin around the neck and lower extremities. A young couple, Bart and Jenny, are expecting a child and are aware there might be a chance that their child could be affected by this disorder. Jenny (the wife) has ichthyosis, but Bart (her husband) is unaffected and completely normal with respect to the allele responsible for this disorder. A. Both Bart and Jenny were Biology majors as undergraduates. Knowing a little about the pattern of X-linked recessive inheritance, Bart and Jenny were concerned when ultrasound revealed that they would be having a son. However, genetic testing performed on the baby shortly after birth revealed that their newborn son, Mark, did not have ichthyosis. Explain how this could be the case, assuming that the gene responsible for ichthyosis is fully penetrant. If non-disjunction occurred, assume it happened in only one of the two parents, and during only one of the two…arrow_forwardIn humans, the allele for normal blood clotting (H) is dominant to the allele for hemophilia. This is a sex-linked trait found on the X chromosome. A woman with normal blood clotting has four children: a normal son, a hemophiliac son, and two normal daughters. The father has normal blood clotting. What is the probable genotype for each member of the family?arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education