Human Heredity Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. The X and Y chromosomes are called the a. extra chromosomes. b. phenotypes. c. sex chromosomes. d. All of the above 2. female : XX :: a. female : gametes c. male : YY b. female : eggs d. male : XY 3. Which of the following is the best explanation for the observation that females rarely get the disease hemophilia? a. Large quantities of male hormones are necessary in order for the allele carrying the disease to be expressed. b. Female fetuses that carry the allele for the disease die before birth. c. A female could get the disease only by having a mother who is a carrier and a father who has the disease. Since most males with the disease do not survive to reproductive age, this is an extremely unlikely event. d. A female could get the disease only by having parents who are both carriers of the disease. Because females cannot be carriers, this is an impossible event. 4. A mutation caused by a piece of DNA breaking away from its chromosome and becoming attached to a nonhomologous chromosome is called a. deletion. c. inversion. b. duplication. d. translocation. 5. A change in a gene due to damage or incorrect copying is called a. evolution. c. segregation. b. meiosis. d. a mutation. 6. The effects of a mutation can be a. helpful. c. neutral. b. harmful. d. All of the above 7. The substance causing permanent alteration to the composition of DNA is called a. a mutation c. a polypeptide b. a mutagen d. a DNA fingerprint 8. A diagram in which several generations of a family and the occurrence of certain genetic characteristics are shown is called a a. Punnett square. c. pedigree. b. monohybrid cross. d. family karyotype. 9. In humans, the risks of passing on a genetic disorder to one’s children can be assessed by a. analysis of a pedigree. b. genetic counseling. c. prenatal testing. d. All of the above 10. While studying several generations of a particular family, a geneticist observed that a certain disease was found equally in males and females and that all children who had the disease had parents who also had the disease. The gene coding for this disease is probably a. sex-linked recessive.

ominant. b. seex-linked do c. au utosomal recessive. d. au utosomal do ominant. The partially p com mpleted pedigree below is i for a familly with a gen netic disordeer.

he pedigree is i most likelyy 11. Referr to the illusttration abovve. The father listed in th ____ _________ _________ _ for the trait. c. dead a. homozygous h d b. heterozygous h s d. bald 12. Referr to the illusttration abovve. Child 3 prrobably has a(n) _____ _________ __________ ____ phenotype. c. homo a. heterozygous h s dominant ozygous receessive b. homozygous h dominant d. codominant 13. If a ch haracteristicc is sex-linkeed, it a. occurs most commonly c in n males. b. occurs only in n females. an never occcur in femalees. c. ca d. iss always fata al. 14. Sincee the allele fo or colorblind dness is located on the X chromosom me, colorblin ndness a. ca annot be inh herited. b. occurs only in n adults. c. iss sex-linked. d. None N of the above a 15. The sex s of an offsspring is dettermined by a. th he mother. c. both parents. b. th he father. d. the offspring. o 16. If non ndisjunction n occurs, a. th here will be too t many ga ametes produ uced. b. no n gametes will w be produ uced. c. a gamete willl receive too many or too o few copies of a chromo osome. d. mitosis m canno ot take placee. 17. A(n) _________ _________ ____ trait is one in whiich males an nd females ca an show diffe ferent phenotypes even when they have h the sam me genotype.. a. seex-linked c. recesssive

18. 19. 20. 21. 22. 23. 24.

25. 26. 27. 28. 29.

30. 31.

32.

b. sex influenced d. homologous Genes contain instructions for assembling a. purines. c. proteins. b. nucleosomes. d. pyrimidines. A mutation that involves one or a few nucleotides is called a(an) a. chromosomal mutation. c. point mutation. b. inversion. d. translocation. Common mutagens include a. sunlight and radiation c. chemicals and sunlight b. radiation and chemical d. all of the above Which of the following is NOT a gene mutation? a. inversion c. deletion b. insertion d. substitution Which of the following is NEVER a frameshift mutation? a. substitution c. deletion b. insertion d. point mutation Mutations which occur without esposure to an obvious mutagen are said to be a. inherited c. fatal b. spontaneous d. all of the above When a piece of chromosome attaches itself to a nonhomologous chromosome, the resulting mutation is called a. translocation c. point b. non dysjunction d. inversion Which of the following traits is controlled by multiple alleles in humans? a. sickle cell anemia c. hemophilia b. blood type d. pattern baldness A mutation in which remaining codons are grouped incorrectly is called a. a point mutation c. a frameshift mutation b. a deletion d. an inversion How many chromosomes are shown in a normal human karyotype? a. 2 c. 44 b. 23 d. 46 Which of the following are shown in a karyotype? a. homologous chromosomes c. autosomes b. sex chromosomes d. all of the above A child born with Turner’s Syndrome is said to have______________, and be a _______________. a. Trisomy XXY, female c. Monosomy X, female b. Trisomy X, female d. Monosomy Y, male What is the approximate probability that a human offspring will be female? a. 10% c. 50% b. 25% d. 75% Nondysjunction mutations occur during ________________ and result in___________ with too few or too many chromosomes. a. mitosis , gametes c. meiosis, gametes b. mitosis, nuclei d. meiosis, genes A person with disorder resulting from monosomy of chromosome 3 has a. 44 autosomes and 2 sexchromosomes c. 44 autosomes and 1 sex chromosome b. 43 autosomes and 2 sex chromosomes d. 43 autosomes and 3 sex chromosomes

33. A person who is heterozygous for a recessive disorder is called a. recessive c. contagious b. dominant d. a carrier 34. A pedigree can be used to a. determine whether a trait is inherited. b. show how a trait is passed from one generation to the next. c. determine whether an allele is dominant or recessive. d. all of the above 35. Which of the following is caused by a dominant allele? a. Huntington’s disease c. Tay-Sachs disease b. PKU d. none of the above 36. A person who has PKU a. inherited the recessive allele for the trait from one parent. b. inherited the recessive allele for the trait from both parents. c. is heterozygous for the trait. d. will not pass the allele for the trait to his or her offspring. 37. People with Down syndrome have a. 45 chromosomes. c. 47 chromosomes. b. 46 chromosomes. d. no X chromosomes. 38. Sickle cell disease is caused by a a. change in one DNA base. b. change in the size of a chromosome. c. change in two genes. d. change in the number of chromosomes in a cell. 39. A human with nondysjunction involving the 8th chromosome may have a. monosomy 8 c. trisomy 8 b. monosomy 15 d. A and C 40. If both parents carry the recessive allele that causes cystic fibrosis, the chance that their child will develop the disease is a. one in two. c. two in five. b. one in four. d. 100%. 41. Most sex-linked genes are located on a. the autosomes. b. the X chromosome only. c. the Y chromosome only. d. both the X chromosome and the Y chromosome. 42. Huntington’s disease is a result of a. a deletion of the CAG triplet c. the insertion of multiple CAG triplets b. a frameshift mutaion d. nondysjunction 43. 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. 44. A genetic disorder resulting in defective blood clotting is a. sickle-cell anemia c. huntington’s b. hemophilia d. down syndrome 45. The formation of a Barr body a. causes the genes on one of the X chromosomes in a female cell to be switched off.

46.

47.

48.

49.

50.

51.

52.

53.

b. always causes the same X chromosome in a female’s cells to be switched off. c. switches on the Y chromosome in a male cell. d. none of the above The name of the scientific program with the goals of constructing physical maps of human chromosomes and determining the DNA sequences of those chromosomes is the a. Human Genome Project c. Proteome Humanities Project b. Down Syndrome Project d. Dolly Symposium A genome is a. an organism’s collection of genes. b. a process used to copy DNA. c. the nucleotide sequence that makes up a particular gene. d. a fragment of DNA added to a chromosome during a recombinant DNA experiment. The Human Genome Project is an attempt to a. make a DNA fingerprint of every person’s DNA. b. sequence all human DNA. c. cure human diseases. d. identify alleles in human DNA that are recessive. A goal of the Human Genome Project is to a. create maps showing where genes are located on human chromosomes. b. create maps showing where chromosomes are located on human genes. c. treat patients with genetic diseases. d. identify people with genetic diseases. One of the surprising discoveries of the Human Genome Project was that a. the human genome consists of only about 30,000 to 40,000 genes. b. 98 percent of the human genome codes for proteins. c. each gene encodes only a single protein. d. the human genome contains no transposons. Transferring normal human genes into human cells that lack them a. is impossible at this time. b. will cause cancer. c. will cause antibodies to kill those cells. d. is called gene therapy. Which of the following information CANNOT be obtained from the Human Genome Project? a. causes of genetic disorders b. amino acid sequences of human proteins c. locations of genes on chromosomes d. whether an allele is dominant or recessive The Humann Genome Project was a effort by a. The US only c. The Us and Europe b. European countries d. some 18 different countries

Gene Mutations

Chromosome Mutations

59. Complete the table above filling in the gene and chromosome types of mutations Hopes

Issues

60. Using the table above list 3 anticipated benefits of the Human Genome Project and 3 social, legal, or ethical issues that are likely to result from this project. Essay: Answer 2 of the 4 questions. 1 of either 61 & 62 and 1 of either 63 & 64 61. In humans, colorblindness is a recessive, sex-linked trait. What is the probability that the children of a woman heterozygous for colorblindness and a man with normal color vision will be colorblind? Explain your answer. Write your answer in the space below. 62. In humans, cystic fibrosis is caused by a recessive gene that is not sex-linked. A man and a woman, neither of whom has cystic fibrosis, have two children with the disease. What is the probability that their third child will have the disease? Write your answer in the space below. 63. Discuss how a karyotype can be used to diagnose Down syndrome. 64. How might karyotypes be useful to doctors?