1. What is the difference between genotype and phenotype? a. Genotype is the physical characteristics; phenotype is the genetic make-up. b. Genotype is the genetic make-up; phenotype is the physical characteristics. c. Genotype is dominant; phenotype is recessive. d. Genotype is recessive; phenotype is dominant. 2. A female guinea pig (homozygous dominant for black fur color) is mated with a male that is homozygous for white fur. In a litter of 8 offspring there would probably be a. 8 white guinea pigs b. 8 black guinea pigs c. 2 black, 4 gray and 2 white guinea pigs d. 4 black and 4 white guinea pigs 3. Because the gene for red-green colorblindness is located on the X chromosome, it is impossible for a a. colorblind father to pass the gene on to his daughter. b. colorblind father to pass the gene on to his son. c. carrier mother to pass the gene on to her daugher. d. carrier mother to pass the gene on to her son. 4. A couple has 2 children, both of whom are boys. What is the chance the parents next child will be a boy? c. 25% b. 50% 5. In fruit flies, eye color is sex-linked and found on the X chromosome. Red eyes (R) are dominant to white eyes (r). If a female fruit fly (heterozygous for red eyes) is crossed with a white-eyed male what percent of their offspring will have white eyes? a. 75% b. 50% 6. Which of the following is a carrier genotype for a sex-linked trait? a. X H X b. X H X h c. X H Y c. 25% d. 0%
A male who suffers from hemophilia (which is a sex-linked trait) is crossed with a female who is a carrier of hemophilia. Use this information to answer questions 7-8. 7. What is the percent chance they will produce a son who expresses the trait? 5% 8. What is the percent chance they will produce a son who is a carrier? 5% 9. What sex is the individual show below and what genetic condition do they have? a. Male, the individual is normal. b. Female, the individual is normal. c. Male, the individual has an extra chromosome. d. Female, the individual has an extra chromosome.
Use the pedigree above to answer questions 10-13 10. Which of the following best describes individual #1 from generation I? a. male with the trait c. female with the trait b. male without the trait d. female without the trait 11. What is the genotype of individual 3 in generation 2? a. X D Y b. X d Y 12. What is the genotype of individual 1 in generation 1? a. X D Y b. X d Y 13. Is it possible to have a male carrier for this trait? a. Yes because it is a trait which experiences simple dominance. b. No because it is a trait which experiences simple dominance. c. X D X D d. X d X d c. X D X D d. X d X d c. Yes because it is a sex-lniked trait. d. No because it is a sex-linked trait. 14. Snapdragon flowers exhibit incomplete dominance. What phenotype would the cross between a red (RR) snapdragon and white (WW) snapdragon produce? a. Pink c. Red b. White d. Purple
Individual # 1 2 3 Genotype XX Xx xx Use the information above to answer questions 15-19 15. The ability to roll your tongue is a dominant trait. Which of the above individuals can roll their tongue? 16. Attached earlobes are a recessive trait. Which of the above individuals have attached earlobes? 17. Which of the above individuals would be a carrier of a recessive trait? 18. If individual 2 were crossed with an individual identical to itself what would be the probability they would have a child which showed the recessive trait? Drawing a Punnett Square would be helpful. b. 75% d. 25% 19. If individual 1 were crossed with individual 2 what would be the probability they would have a child which showed the recessive trait? b. 75% d. 25%
Use this karyotype above to answer question 20 20. What is wrong with the above individual? a. The above individual is normal. b. The above individual has an extra chromosome c. The above individual is missing a sex chromosome 21. Which of the sex chromosomes determines the presence or absence of a sex-linked trait? a. X c. 18 b. Y d. 21 22. Why are sex-linked traits only carried on one of the sex chromosomes? a. The X chromosome is dominant. b. The Y chromosome is dominant. c. The Y chromosome is missing the necessary section (too small) to carry all the sex-linked traits. d. The X chromosome is too small is carry all the sex-linked traits.