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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
- Red-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_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_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_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
- 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_forwardRed-green color blindness is an X-linked recessive trait in humans. Polydactyly (extra fingers and toes) is an autosomal dominant trait. Martha has normal fingers and toes and normal color vision. Her mother is normal in all respects, but her father is color blind and polydactylous. Bill is color blind and polydactylous. His mother has normal color vision and normal fingers and toes. When answering the given question, consider that the answers include the proportions of only some of the possible phenotypes; other phenotypes are also expected to occur but are not included. If Bill and Martha marry, what proportions of children with specific phenotypes would they be expected to produce? 1/8 color-blind girls with normal fingers, 1/4 boys with normal vision and polydactyly 1/4 girls with normal vision and polydactyly, 1/8 boys with normal vision and polydactyly 1/8 color-blind girls with polydactyly, 1/8 boys with normal vision and normal fingers 1/4 color-blind girls with normal fingers,…arrow_forward
- in humans, as well as with many other animals, sex is determined by special sex chromosomes. An individuai containing two X chromosomes is a female, while an individual possessing an X and Y chromosome is a male. The sex chromosomes bear alleles for traits. Sex linkage applies to genes that are located on the sex chromosomes. These genes are considered sex-linked because their expression and inheritance patterns differ between males and females. The genes present on the X chromosome are said to be X linked. Many more genes are present on the A chromosome than found on the Y chromosome. Nonetheless, those genes found on the Y chromosome are said to be Y linked. The Y chromosome is smaller than its homoloque, the X chromosome. Consequently, most of the loci present on the X chromosome are absent on the Y chromosome. 1. In humans, hemophilia is a sex linked trait. Females can be normal, carriers, or have the disease. Males will have the disease or not (but they won't be ever carriers) XH…arrow_forwardOne type of colorblindness is an X-linked recessive trait. If a colorblind man and a woman with normal vision but whose father was colorblind have a girl, what is the probability she will be colorblind? If they have a boy what is the probability he will be colorblind? 1/2 for the girl; 1/4 for the boy O 1/2 for the girl; 100% for the boy O 1/2 for the girl; 1/2 for the boy 1/4 for the girl; 1/2 for the boy O for the girl; 1/2 for the boyarrow_forwardAlbinism is an autosomal (not sex-linked) recessive trait. A man and woman are both of normal pigmentation and have one child out of three who is albino (without melanin pigmentation). What are the genotypes of the albino's parents? Both parents must be homozygous dominant. Both parents must be heterozygous. One parent must be homozygous dominant; the other parent must be heterozygous. One parent must be heterozygous; the other parent can be homozygous dominant, homozygous recessive, or heterozygous. One parent must be homozygous for the recessive allele; the other parent can be homozygous dominant, homozygous recessive, or heterozygous. O O O O Oarrow_forward
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