1. Somatic cells in humans have __________ chromosomes.

A. 23 B. 46 C. 92

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2. When a karyotype is done chromosomes are arranged in pairs based on _____.

A. size B. shape C. centromere location D. all of the above ___

4. A display of the pairs of chromosomes is called a _____.

A. pedigree chart B. karyotype C. caricature D. chromosome map

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5. Fetal cells can be obtained for diagnostic purposes during _____.

A. chorionic villi sampling B. fertilization C. amniocentesis D. both A and C ___

7. In humans there are _____ pairs of autosomes.

A. 22 B. 23 C. 44 D. 88

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8. Nondisjunction _____.

A. results in gametes with too few chromosomes B. can occur during meiosis I C. can occur during meiosis II D. all of the above ___

10. The most common autosomal trisomy among humans is _____.

A. trisomy 21 B. trisomy 13 C. trisomy 18

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11. Persons with Down syndrome usually have __________ copies of chromosome 21 in their karyotype.

A. two B. three C. four

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12. Which of the following would be the result of nondisjunction of the sex chromosomes?

A. Turner syndrome XO B. Down syndrome trisomy 21 C. Edward syndrome trisomy 18 D. Patau syndrome trisomy 13

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14. If an egg with 22 autosomes is fertilized by a sperm with 22 autosomes and an X chromosome, the offspring will be_____.

A. female, XO B. female, XXX C. male, OY D. male, XXY

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15. Individuals with Down syndrome have three copies of _____.

A. the X chromosome B. chromosome 13 C. chromosome 21 D. the Y chromosome

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16. Which of the following symptoms of Down syndrome may be associated with the Gart gene?

A. leukemia B. mental retardation C. accelerated rate of aging D. cataracts

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17. Turner females, XO, are characterized by _____.

A. normal breast development B. regular menstrual cycles C. infertility D. none of the above

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20. Klinefelter males are characterized by _____.

A. two Y chromosomes B. underdeveloped testes and prostate glands C. normal size hands and feet D. all of the above

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21. Fragile X syndrome is characterized by _____.

A. autism B. delayed speech development C. hyperactivity D. all of the above ___

22. Jacob syndrome (XYY) is caused by nondisjuction that occurred during _____.

A. meiosis I B. meiosis II ___

23. When Down syndrome tends to run in the family of the father or mother the cause is _____.

A. the advanced age of the mother B. a translocation between chromosomes 14 and 21 C. a deletion from chromosome 21 D. duplication of chromosome 18

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24. A _____ is characterized by only one of a particular kind of chromosome instead of a pair.

A. monosomy B. disomy C. trisomy

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25. Fragile X syndrome is characterized by _____.

A. an extra X chromosome B. over 230 copies of the base triplet CGG in the fragile X chromosome C. the absence of a Y chromosome D. a normal phenotype

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30. Which of the following is an autosomal recessive disorder?

A. cystic fibrosis B. Huntington disease C. color blindness D. all of the above

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31. Huntington disease leads to _____.

A. degeneration of brain cells B. severe muscle spasms C. personality disorders D. all of the above ___

32. The pattern of inheritance for a particular condition is shown by a _____.

A. karyotype B. caricature C. pedigree chart D. chromosome map

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34. When a genetic disorder is a simple autosomal dominant an individual with the alleles _____ will have the disorder.

A. tt B. TT C. Tt D. both B and C are correct ___

35. In a pedigree chart _____.

A. a shaded circle represents a normal (unaffected) female B. a square represents an affected male C. a line between a circle and a square represents a union D. all of the above

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36. Parents that appear to be normal but are capable of having a child with a genetic disorder are _____.

A. carriers B. mutants C. homozygous recessive D. homozygous dominant

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38. Which of the following is characteristic of an autosomal dominant disorder?

A. most affected children have affected parents

B. heterozygotes have a normal phenotype C. two affected parents can have an unaffected child D. males are affected more often than females

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39. Parents who are both carriers for an autosomal recessive disorder have a _____ chance of having a child with thedisorder.

A. 10% B. 25% C. 50% D. 75%

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41. Which of the following characterizes autosomal recessive disorders?

A. heterozygotes with normal phenotypes B. affected parents always having affected children C. affected individuals with homozygous dominant mates having unaffected children D. all of the above ___

43. Which of the following is an autosomal dominant disorder?

A. Huntington disease B. cystic fibrosis C. hemophilia D. Tay-Sachs disease

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44. Which of the following is true of Neurofibromatosis?

A. most people appear normal until middle age B. in most cases, the symptoms are mild and patients live a normal life C. the mutant allele is located on the X chromosome D. heterozygotes will have a normal phenotype

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46. Which of the following is true of Huntington disease?

A. more females than males are affected B. it is easily cured C. it is the result of a deletion from chromosome 21 D. the more repeats of the base triplet CAG, the more severe the symptoms are

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49. The most common lethal genetic disorder among Caucasians in the US is _____.

A. Tay Sachs disease B. color blindness C. cystic fibrosis D. neurofibomatosis

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51. Cystic fibrosis is characterized by _____.

A. thick and viscous mucus in the bronchial tubes B. an average life expectancy of 17-28 years of age C. failure of the chloride ions to pass through plasma membrane channel proteins D. all of the above ___

52. Tays Sachs disease usually occurs in _____.

A. Jewish people of central and eastern European descent B. African-American people C. males D. Native Americans

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53. Diet soft drinks have a warning on them that applies specifically to individuals who have _____.

A. color blindness B. Tay Sachs disease C. neurofibromatosis D. phenylketonuria ___

54. The frequency of the phenotypes of traits controlled by _____ follows a bell-shaped curve.

A. polygenic inheritance B. autosomal recessive inheritance C. codominance D. multiple alleles

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55. Which of the following alleles for blood type is dominant?

A. A B. B C. O D. both A and B ___

57. If a man with blood type A has a child with blood type O, the father's genotype must be _____.

A. AA B. AB C. AO D. OO

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59. The distribution and variation of the phenotypes can be influenced by _____.

A. the number of genes that control the trait B. environmental effects C. both A and B ___

61. Codominance in humans is displayed by people with _____.

A. AB blood type B. color blindness C. cystic fibrosis D. very dark skin color

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62. An example of a human disorder that is controlled by incompletely dominant alleles is _____.

A. hemophilia B. sickle-cell anemia C. color blindness D. Tay-Sachs disease

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64. The allele for sickle cell is more commonly found in _____.

A. Jewish people of central and eastern European descent B. African-American people C. males D. Native Americans

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65. Genetic counseling relies on _____.

A. pedigree charts B. blood tests for faulty enzymes C. chromosomal tests D. all of the above ___

67. Which is an X-linked recessive disorder?

A. color blindness B. hemophilia C. muscular dystrophy D. all of the above ___

68. The alleles of most sex-linked genetic disorders are on the _____ chromosome.

A. X B. Y

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70. Which of the following is typical of X-linked recessive conditions?

A. more males than females are affected B. females can be carriers C. all the sons of a female who has the condition will have the condition D. all of the above ___

71. The daughters of a man who is color blind and a woman who is homozygous dominant will _____.

A. be carriers B. be color blind C. have normal vision D. both A and C ___

73. Which of the following is on the X chromosome?

A. the gene for red-sensitive protein B. the gene for A-antigen on red blood cells C. the gene for the enzyme that breaks down phenylalanine D. the gene for the enzyme hexosaminidase

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74. Which of the following is characteristic of Duchenne muscular dystrophy?

A. toe walking B. passage of the recessive allele from carrier mother to carrier daughter C. an absence of a protein called dystrophin D. all of the above ___

76. Queen Victoria was a carrier for hemophilia so her sons had a _____ chance of inheriting the disease.

A. 25% B. 50% C. 75% D. 100%

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79. Which of the following is true of hemophilia?

A. there is only one type of hemophilia B. the affected people only bleed externally after an injury C. more females than males are affected D. the genetic engineering product, factor VIII, can be used to treat hemophilia B

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80. Tests are available to detect _____.

A. carriers of Duchenne muscular dystrophy B. the presence of the gene for Huntington disease C. carriers of cystic fibrosis D. all of the above ___