MULTIPLE CHOICE 1. In Drosophila, the gene for red and white eye color is located on the X chromosome. The cross of a homozygous wild type red eyed female fly with a white eyed male fly results in which offspring? a. all red eyed females and males b. red eyed females and white eyed males c. all red eyed females, males are red and white eyed d. females are ‘h red and % white eyed; males are % red and ‘/% white eyed 2. The cross of a white eyed female fly with a wild type red eyed male results in which offspring? a. all red eyed females and males b. red eyed females and white eyed males c. all red eyed females; males are % red and ‘h white eyed d. females are ‘Ve red and V white eyed; males are /h red and ‘/h white eyed 3. Nondisjunction may involve which type of chromosome? a. X chromosome b. Y chromosome c. Autosomes d. All of the above 4. Which of the following is nondisjunction? Homologous chromosomes 21 do not move to opposite poles in Meiosis I. Homologous X chromosomes do not move to opposite poles in Meiosis I. Sister chromatids of X chromosome do not move to opposite poles in Meiosis II. Sister chromatids of chromosome 21 do not move to opposite poles in Meiosis II All of the above a. b. c. d. e. 5. In humans, gender is determined by the presence or absence of which chromosome? a. chromosome 1 b. X chromosome c. Y chromosome d. Chromosome 21 syndrom 6. With respect to the sex chromosomes, the genotype of a person with Turner is 7. Phenotypically, a person with the genotype XXY would a. be male b. be female c. have Klinefelter syndrome d. have Turner syndrome e. both a and c 8. A woman who is heterozygous for a particular X-linked recessive trait marries a phenotypically normal man. What percentage of their daughters will show the recessive phenotype? a. 0 b. 25 c. 50 d. 100 9. A woman who is heterozygous for a particular X-linked recessive trait marries a phenotypically normal man. What percentage of their sons will show the recessive phenotype? a. 0 b. 25 c. 50 d. 100 10. A research technician observes cells scraped from the mouth of a patient under the light microscope. The cells came from a woman because they contain: a. two X chromosomes b. inactivated Y chromosomes c. Barr bodies d. Lyon mosaics BONUS: An X-linked dominant allele causes hypophosphatemia in humans. A man with hypophosphatemia marries a normal woman. What proportion of their sons will have hypophosphatemia? Show your work!!!!