Name: Period: Date: Practice Study Guide Genetics: Solve the following questions: Problem 1: a. What is the most likely mode of inheritance for this pedigree? Why? Problem 2: Assume that the individual marked with an asterisk (*) does not carry any allele associated with the affected phenotype and that no other mutation spontaneously occurs. Also assume complete penetrance. Use R or XR for the allele associated with the dominant phenotype, r or Xr for the allele associated with the recessive phenotype. a. List all possible genotypes of the following individuals in the pedigree. Individual: All possible genotypes: 1. 2. c. What is the probability of Individual A being affected? d. What is the probability of Individual B being affected?
e. What is the most likely mode of inheritance for this pedigree? Why? Problem 3: In plants known as four o clocks, the allele for the dominant red-flower color is incompletely dominant over the allele for white-flowers. A gardener allows several heterozygous pink- flowered four o clocks to self pollinate and collects 200 seeds. Draw a Punnett square for the cross. Identify the flower color phenotypes and genotype percentages. Problem 4: Mrs. Eryth is carrier of the sex-linked hemophilia allele (XAXa) and Mr. Eryth is normal (XAY). a. Draw a Punnet square that shows the theoretical genotypes and phenotypes among their children. b. They actually have 4 male and 4 female children; how many of each sex would be expected to be hemophiliacs, carriers, and normal? Problem 5: In rabbits, white coat color (C W ) and black coat color (C B ) are codominant, and both of these alleles are dominant over albino (c); heterozygotes (C W C B ) are spotted. Draw a Punnett Square that shows the genotypes and phenotypes of the offspring from a heterozygous black-coated rabbit and a
homozygous white-coated rabbit? Multiple Choice Practice: 1. What is probability? a. likelihood that a particular event will occur b. automatic outcome of events based on math c. an estimation based on guesswork d. predictions based on random calculations from monkeys 2. A capital letter in a punnett square cross means a. Dominant b. Recessive c. Co-dominant d. None of the above 3. The word phenotype means a. Latin for unseen trait b. Latin for to see c. Hidden trait d. The result of a genotype 4. Genotype means a. Combination of alleles b. Combination of genes c. Combination of physical traits d. None of the above. 5. Homozygous means. a. Alleles are different
b. Alleles are the same c. Alleles are mismatched d. Combination of alleles 6. IF Y is green, y is yellow and you cross YY x yy. Then, how many offspring will be yellow? a. 0 b. 1 c. 2 d. 3 7. According to our case study of sickle cell anemia, traits are. a. variables that change quickly due to external pressures such as disease. b. less likely to be preserved due to natural selection s randomness. c. remain unchanged and the same in a population due to genetic and environmental pressures. d. tend to remain and be different due to the genetic and environmental pressures that keep these traits in a population. 8. On an isolated island in the Caribbean a species of anole lizards are moved to a different island. The anole lizards originally had long legs adapted to running on the open space of the original island, however this new island is covered in short shrubs making running impossible. What is most likely to happen to the anole lizards? a. The anoles are likely to die off, due to this island being unsuitable to their body structure. b. The new environment will select for shorter legs more adapted to climbing shrubs. c. The new environment will result in a genetic mutation to rapidly cause the anole lizards to develop a body structure more adapted to the shurby island. d. Natural selection will favor lizards with shorter legs, eventually the lizards will develop shorter legs, however longs legs will remain in the gene pool. 9. If you cross Tt x Tt what will be the percent of offsprings with tt? a. 100% b. 75% c. 50% d. 25% 10. If you cross TT x Tt what will be the percent of offspring that are TT?
a. 100% b. 75% c. 50% d. 25% 11. What happens if you breed two parents who are homozygous for different traits together? a. The dominant trait will be present in only 75% of the kids. b. The dominant trait will be present in 100% of the kids. c. The recessive trait is not present at all. d. The dominant/recessive trait is present in 100% of the kids. 12. If you breed two plants from the F1 generation. How many of the offspring will be heterozygous? a. 0% b. 25% c. 50% d. None of the above. 13. f you breed two true breeding plants. How many of the offspring will be heterozygous? a. 0 % b. 25% c. 50% d. None of the above. 14. Why are most genetic disorders commonly inherited from the X chromosome? a. Its larger than the Y b. It s smaller than the Y. c.it contains more genes making it larger. d. It contains less genes making it smaller. 15. If Dad is XHY and mom is XHXh than what is the likleihood the offspring will have hemophillia? Note: Hemophillia is a sex-linked recessive disorder) a. 0% b. 25% c. 75% d. None of the above. 16. What type of genetic disorder is sickle cell anemia? a. Autosomal recessive disorder b. Autosomal dominat disorder c. X-linked Dominant disorder
d. X-linked Recessive disorder 17. What are the odds of a child having sickle cell anemia if both parents are carriers for the disease? a. 100% b. 75% c. 50% d. 25% 18. Natural selection is not strong against those born with the Huntington s disease. What evidence supports this claim? a. The disease is recessive and kills them prior to reproductive age. b. The disease is recessive and onset is after reproductive age. c. The disease is dominant and it s onset is later in life. d. The disease is dominant and kills them prior to reproductive age. 19. How does selection work based on Sickle Cell Anemia? a. It ensures only the strong survive. b. It provides the most available advantage. c. It ensures only the most fit survive. d. It kills off the weak. 20. A cross of a white hen with a black rooster produces speckled-color offspring. This type of inheritance is known as a. incomplete dominance. c. codominance. b. polygenic inheritance. d. multiple alleles. 21.Colorblindness is more common in males than in females because a. fathers pass the allele for colorblindness to their sons only.
b. the allele for colorblindness is located on the Y chromosome. c. the allele for colorblindness is recessive and located on the X chromosome. d. males who are colorblind have two copies of the allele for colorblindness. 22. How many chromosomes are shown in a normal human karyotype? a. 2 c. 44 b. 23 d. 46 23. Linked genes are a. are never separated b. assort independently c. are on the same chromosome d. are always recessive 24. Meiosis results in the formation of a. 4 diploid daughter cells. b. 4 haploid daughter cells c. 2N daughter cells d. 4 body cells 25. Scientist test for alleles that cause human genetic disorders by a. Making karyotypes b. Using DNA probes c. Making DNA fingerprints d. Making pedigrees.