Zoo 317 Heredity, Evolution and Society |
Final Exam, Fall 1998
Mark the best answer to each question on the separate answer sheet with a #2 pencil. If you erase, do so thoroughly. Answer sheets must be turned in no later than 12:00. The answer key will be posted outside the examination room.
1. Prokaryotes are different from eukaryotes in that prokaryotes
a. lack a nucleus.
b. lack a cell membrane
c. lack genes.
d. are unicellular.
2. The S phase of the cell cycle is when
a. chromosomes divide.
b. DNA is synthesized.
c. symbiosis occurs.
d. sexual recombination occurs.
3. Chromosomes are said to be homologous
a. when they originate from the same fertilized egg.
b. when they have the same microscopic form.
c. when they have the same array of genes.
d. if they go to the same daughter cell in cell division.
4. During cell division, chromosomes are maximally condensed during
a. anaphase.
b. telophase.
c. prophase.
d. metaphase.
5. A cell divides, producing two daughter cells that have the same chromosome complement as the parent cell. This form of cell division is known as
a. cytokinesis.
b. meiosis.
c. endoreduplication.
d. mitosis.
6. The chromosome complement after meiosis normally is
a. haploid.
b. polyploid.
c. aneuploid.
d. heteroploid.
7. Crossing over provides a means of
a. repairing mutations.
b. segregation of mutant alleles.
c. genetic recombination.
d. epistasis.
8. In humans, spermatids have _____ chromosomes.
9. A dihybrid cross is so named because observations are made on two
a. alleles.
b. chromosomes.
c. loci.
d. species.
10. In a cross between two pure strains of mice, one of which is homozygous for the recessive gene for albinism, the ratio of AA:Aa:aa in the F2 generation is
a. 2:1:1.
b. 1:2:1.
c. 1:1:2.
d. 3:1:1.
11. Achondroplasia is a rare autosomal dominant trait. An affected man produces sperm of which _____% carry the achondroplasia allele.
12. Two persons with autosomal recessively inherited albinism marry. Their ten children all have normal pigmentation. Most probably,
a. the parents are homozygous for albino alleles at different loci.
b. the albino allele mutated back to normal in one of the parents.
c. the parents are related.
d. the mother transmitted a virus that causes normal pigmentation to all her children.
13. [This question was a graphical pedigree problem that is not set up for web viewing.]
14. Crossing over
a. never occurs between the X and the Y chromosomes.
b. occurs only in the pseudoautosomal region of the X and Y chromosomes.
c. occurs only in regions of homologous genes on both arms of the X and Y chromosomes.
d. occurs throughout the length of the X and Y chromosomes.
15. A particular trait occurs twice as often in girls as in boys. Based only on this consideration, one might suspect that the trait is inherited as
a. an autosomal dominant.
b. an autosomal recessive.
c. an X-linked dominant.
d. an X-linked recessive.
16. Genetic markers on the non-pseudoautosomal region of the Y chromosome are useful in some studies because
a. they are uniform in the population.
b. they code for male sex hormones.
c. they do not recombine.
d. they are identical in higher primates.
17. A boy with blond hair dyed it to match the (undyed) brown hair of his brother. He is now an example of
a. imprinting.
b. epistasis.
c. a phenocopy.
d. genetic dissociation.
18. In a pedigree that shows maternal inheritance of a trait,
a. only females are affected.
b. approximately half the offspring of an affected female are also affected.
c. all the offspring of an affected female are also affected.
d. only persons who receive the X chromosome with the variant allele are affected.
19. A genetic map of a chromosome is based on
a. the frequency of crossing over between loci.
b. the distance between loci measured microscopically.
c. binding of DNA probes to specific sites.
d. the number of nucleotides between adjacent restriction sites.
20. Which of the following is especially valuable in constructing physical maps of human genes?
a. In situ hybridization
b. dihybrid crosses
c. measurement of recombination frequencies
d. genotypic ratios
21. Which of the following traits is polygenic?
a. sex
b. sickle cell anemia
c. intelligence
d. PKU
22. The proportion of genes that one has in common with one's aunt is
a. 1/2.
b. 1/4.
c. 1/8.
d. 1/16.
23. If a twin has cleft palate, the frequency of cleft palate in the co-twin is 40% if they are monozygotic and 5% if they are dizygotic. This proves that
a. cleft palate is a Mendelian trait.
b. cleft palate is inherited but polygenic.
c. both heredity and nonhereditary factors influence the risk of cleft palate.
d. the intra-uterine environment of twins creates a risk of cleft palate.
24. The average height of present-day Americans of European descent is greater than the height of Medieval Europeans. This means that
a. heritability of height is high.
b. heritability of height is low.
c. present-day Americans are more likely to reach their genetic potential for height.
d. This comparison provides no information on the question of heritability of height.
25. The karyotype formula for persons with Klinefelter syndrome is
a. 45,X.
b. 47,XYY.
c. 47,XXY.
d. 46,XX.
26. Triploid cells often occur as a result of
a. nondisjunction.
b. failure of chromosome pairing.
c. double ovulation.
d. double fertilization.
27. One indication for prenatal testing for chromosome abnormalities is
a. advanced maternal age.
b. advanced paternal age.
c. excessive use of alcohol by the mother.
d. excessive use of alcohol by the father.
28. Persons with the fragile-X syndrome
a. have a condition that resembles Turner syndrome.
b. most often are mentally retarded males.
c. produce only male offspring.
d. rarely survive the neonatal period.
29. Balanced translocations are problems because
a. they form quadriradial figures in meiosis.
b. they often form unbalanced gametes.
c. they cause the expression of recessive genes.
d. they form isochromosomes.
30. Duplications of a chromosomal segment are likely to be better tolerated than deletions because
a. only one of the two duplicated segments is functional.
b. duplications do not present the pairing problems in meiosis that deletions do.
c. duplications occur only in euchromatin.
d. the hemizygosity created by a deletion allows recessive alleles on the normal chromosome to be expressed.
31. Teratogens are agents that cause
a. chromosomal aberrations.
b. developmental defects.
c. frameshift mutations.
d. immune disorders.
32. The process of differentiation involves
a. selective loss of chromosomes in different tissues.
b. selective elimination of genes in different tissues.
c. selective activity of genes in different tissues.
d. recombination of genes in different tissues.
33. Most persons with one sex-chromatin body are
a. normal males.
b. normal females.
c. true hermaphrodites.
d. male pseudohermaphrodites.
34. From the genetic point of view, sex is primarily
a. a means of producing offspring.
b. a means of producing new combinations of genes.
c. a means of reducing genetic variability.
d. an essential element for evolution.
35. Heterozygous females are mosaic for expression of most genes on the X chromosome because of
a. hybrid dysgenesis.
b. X-chromosome inactivation.
c. somatic mutation.
d. autoimmune suppression.
36. When an atom gains or loses an electron, it becomes
a. an ion.
b. a pion.
c. a meson.
d. an exon.
37. An element has an atomic number of 35. Therefore, it has
a. a mass of 35 daltons.
b. 35 neutrons.
c. 35 protons.
d. 35 total nuclear particles.
38. Which of the following nucleotide pairs are found in DNA?
a. A-T and G-C.
b. A-U and G-C.
c. A-G and T-C.
d. A-T, T-C, and U-G.
39. The two strands of a DNA double helix are described as antiparallel. This is because
a. they are oriented in opposite directions with respect to each other.
b. they are folded in a helix rather than in a straight line.
c. the paired bases are not identical to each other.
d. there are restrictions on which bases can pair with which.
40. A primer is required in order for a new DNA strand to be copied, using an old strand as a template.
a. The purpose of the primer is to catalyze addition of the new nucleotides.
b. The new nucleotides can be added to either end of the primer.
c. The new nucleotides can only be added to the 5' end of the primer.
d. The new nucleotides can only be added to the 3' end of the primer.
41. Genetic information for protein structure goes from the nucleus to the cytoplasm in the form of
a. transfer RNA.
b. ribosomal RNA.
c. messenger RNA.
d. small nuclear RNA.
42. Which of the following organelles is the site of protein synthesis?
a. ribosomes
b. lysosomes
c. nucleosomes
d. Golgi bodies
43. Abraham Lincoln is thought to have been affected by Marfan syndrome, which is a defect in
a. an enzyme involved in fat synthesis.
b. a structural protein.
c. a growth hormone.
d. steroid synthesis.
44. The term "inborn error of metabolism" refers to inherited diseases that
a. are caused by a defective enzyme.
b. are associated with congenital defects.
c. can be treated with diet.
d. affect ribosome structure.
45. PKU (phenylketonuria) is an example of an inherited disease that can be controlled by
a. drugs.
b. diet.
c. hormones.
d. exercise.
46. Persons with dominant familial hypercholesterolemia
a. have defective cell-membrane receptors for binding low-density lipoprotein (LDL).
b. cannot absorb cholesterol from the gut.
c. cannot absorb unsaturated fats from the gut.
d. lack an enzyme that is essential for the breakdown of cholesterol.
47. Sickle cell anemia causes problems because
a. it cannot transport oxygen.
b. it also binds to carbon monoxide.
c. it forms a crystal-like structure in the absence of oxygen.
d. it cannot cross the cell membrane.
48. A somatic mutation is one that
a. occurs in an autosomal gene.
b. occurs in a germ cell.
c. occurs in a cell other than a germ cell.
d. is expressed only in somatic tissues.
49. A loss of one nucleotide from a coding sequence is most likely to cause
a. a frameshift mutation.
b. a sense mutation.
c. a nonsense mutation.
d. a missense mutation.
50. Many mutations are not transmitted to offspring because
a. they are repaired.
b. they occur on the inactive X chromosome.
c. they involve changes in RNA rather than DNA.
d. they occur in noncoding regions of DNA.
51. Gene manipulation in the laboratory makes extensive use of enzymes that can cleave DNA only at specific base sequences. These enzymes are called
a. DNA polymerases.
b. trypsins.
c. nucleocides.
d. restriction enzymes.
52. Human genes can be inserted readily into bacteria if the genes are first inserted into
a. DNA.
b. lymphocytes.
c. human retroviruses.
d. plasmids.
53. In a Southern blot, DNA fragments are separated on the basis of their
a. nucleotide sequence.
b. size.
c. order on the chromosome.
d. function.
54. The polymerase chain reaction is
a. a way in which cells can increase the amount of mRNA.
b. a means of amplifying the amount of DNA in a cell.
c. a means of amplifying a specific segment of DNA in the laboratory.
d. a nuclear reaction that leads to radon.
55. A transgenic plant is one that
a. is produced by hybridization of two closely related species.
b. has been modified by artificial selection.
c. has had a foreign gene introduced into it.
d. transmits genes to other plants through pollen.
56. A DNA probe binds to
a. regions of complementary DNA.
b. all DNA.
c. coding regions of DNA.
d. proteins that regulate DNA activity.
57. Restriction fragment length polymorphisms are
a. variations in presence or absence of DNA restriction sites.
b. variations in splicing of premessenger RNA.
c. presence or absence of cell surface restriction receptors.
d. variations in location of termination codons.
58. Mitochondrial DNA markers in old bones are sometimes compared to those from living persons in order to establish relationships between the two persons. Mitochondrial markers are selected because
a. mitochondria do not undergo genetic recombination.
b. there are more copies of mitochondrial genes than nuclear genes.
c. mitochondrial genes are more stable than nuclear genes.
d. the complete sequence of mitochondrial DNA is known.
59. In many families, high risk of breast cancer is transmitted as a dominant trait due to a variation in the structure of the BRCA gene on chromosome 17. The earliest that this DNA change can be detected is
a. in the 8-cell embryo stage.
b. at about 10 weeks gestation by means of chorionic villus biopsy.
c. at about 16 weeks gestation by means of amniocentesis.
d. in the newborn.
60. Retroviruses are
a. viruses that use RNA as a template to make DNA.
b. viruses that cause dedifferentiation of mammalian tissues.
c. viruses that infect bacteria.
d. viruses that cause nondisjunction in mammals.
61. Which statement best describes our understanding of cancer?
a. Most human cancer is due to mutations in somatic cells.
b. Most human cancer is due to virus infections.
c. All cancer is due to inherited predisposition.
d. Except for very rare cases, all cancer is due to exposure to environmental agents.
62. A general characteristic of cancer cells is
a. unregulated production of cell growth factors.
b. the presence of viral oncogenes.
c. the absence of cellular oncogenes.
d. loss of cellular antigens.
63. Gene amplification is often observed in cancer cells. Gene amplification refers to
a. increase in the number of copies of certain genes.
b. abnormal transcription of certain genes.
c. abnormal transcription of all genes.
d. increased responsiveness of specific gene targets.
64. DNA from a person tests positive for a certain oncogene. Most likely, the person
a. has cancer.
b. has increased risk of developing cancer.
c. has a retroviral infection.
d. is normal, since all normal persons have oncogenes in their DNA.
65. Inherited risk of cancer is due sometimes to mutations in
a. mitochondrial genes.
b. genes that code for lysosomal enzymes.
c. DNA repair genes.
d. DNA polymerase.
66. When a foreign substance is introduced into an animal, those cells that are programmed to produce specific antibodies to it are stimulated to grow. This concept is known as
a. the clonal selection theory.
b. autoimmunity.
c. mitotic drive.
d. transformation.
67. Immune tolerance refers to
a. failure to make antibodies against certain viruses and bacteria.
b. tolerance of exposure to infectious agents to which one is immune.
c. failure to make antibodies against one's own tissues.
d. tolerance of organ transplants due to immunosuppressive drugs.
68. In order for organ transplants to be successful, donor and recipient should ideally be matched for
a. MHC type.
b. Duffy type.
c. MN type.
d. hemoglobin type.
69. A man is blood group O. He could not be the father of a child who is
a. type A.
b. type B.
c. type AB.
d. type O.
70. Hemolytic disease of the newborn occurs primarily when
a. the mother and father are both Rh+.
b. the mother is Rh+ and the father is Rh–.
c. the mother is Rh– and the father is Rh+.
d. the mother and father are both Rh–.
71. Since Tay-Sachs disease can be diagnosed prenatally,
a. all pregnancies should be checked for TSD.
b. all pregnancies in which both parents are Jewish should be checked.
c. only pregnancies in which both parents are proved heterozygotes need be checked.
d. only pregnancies in which at least one parent has TSD need be checked.
72. Various racial and ethnic groups in the U.S. give different results on the standard IQ test.
a. Since IQ is inherited in part, the different groups must differ in the inheritance of genes for intelligence.
b. This is because of environmental rather than genetic differences.
c. The test is invalid.
d. No inference can be made about the roles of heredity and environment in these differences.
73. Alzheimer disease
a. is always transmitted as a monofactorial trait.
b. is always transmitted as a multifactorial trait.
c. is monofactorial in some families but multifactorial in most families.
d. clusters in families because of exposure to an agent in the environment.
74. The frequency of cystic fibrosis (an autosomal recessive trait) is 1/2500 among newborns. Therefore the allele frequency is
a. 0.0004.
b. 0.02.
c. 0.04.
d. 0.0016.
75. The term assortative mating refers to
a. panmixis.
b. avoidance of mates with similar genotypes.
c. selection of mates independent of the genotypes.
d. selection of mates with similar genotypes.
76. The allele frequency for Huntington disease is 0.0001. The frequency of persons who are heterozygous for Huntington disease is approximately
a. 0.000,000,01.
b. 0.0001.
c. 0.0002.
d. 0.01.
77. A population consists of 49 AA, 42 Aa, and 9 aa persons. What is the frequency of the allele a?
a. 0.03.
b. 0.09.
c. 0.30.
d. 0.51.
78. The Hardy-Weinberg law applies to populations in which
a. every individual leaves the same number of offspring.
b. polymorphisms are rare.
c. random mating occurs.
d. there are equal numbers of males and females.
79. A common test of whether two populations of organisms are in the same species is
a. whether they have similar karyotypes.
b. whether they occupy similar ecological niches.
c. whether they produce fertile hybrid offspring.
d. whether they will mate.
80. Which of the following is the correct sequence going from most inclusive group to smaller groups in the Linnaean system?
a. Genus, phylum, order.
b. Species, family, genus.
c. Phylum, genus, species.
d. Genus, species, kingdom.
81. Linnaeus constructed a system of classification of living plants and animals based on
a. their relationships to fossil forms.
b. the evolutionary relationships among them.
c. similarities and differences in visible form and function.
d. their geographic origin.
82. Which of the following body forms would be best adapted to a cold climate?
a. Small volume, round shape.
b. Small volume, thin shape.
c. Large volume, round shape.
d. Large volume, thin shape.
83. Persons of African origin are often resistant to vivax malaria because
a. they are Rh-negative.
b. they lack the specific malarial receptors on their red cells.
c. they do not attract the specific mosquito vector.
d. they are heterozygous for sickle cell anemia.
84. The Rh blood types have been especially useful as genetic markers because
a. they are polymorphic in every population.
b. they are the products of several loci.
c. they show maternal inheritance.
d. they can also be detected on individual sperm.
85. Diabetes mellitus is detrimental without modern medication. It's high frequency is thought to result from
a. a high mutation rate.
b. selection that favors the diabetic genotype under primitive feast-or-famine conditions.
c. heterozygote advantage in areas of high malaria.
d. high fertility.
86. The most important measure of Darwinian fitness is
a. average life span.
b. number of offspring.
c. relative body size.
d. annual income.
87. Sickle cell anemia occurs in high frequency in Africa because
a. heterozygotes are resistant to falciparum malaria.
b. affected persons are resistant to intestinal parasites.
c. it is transmitted from monkeys.
d. it provides adaptation to hot tropical climates.
88. One factor that contributes to evolution is
a. genetic drift.
b. homozygosity for recessive genes.
c. low levels of inbreeding.
d. gene splicing.
89. The DNA sequence for a particular gene segment in species X is 5'-GATTCTAAACGCCGTAA-3'. Sequences for homologous segments in related species a-d are listed below. Which species is the most closely related to species X?
a. 5'-GAACCTATGGGCCGTAA-3'
b. 5'-GATCCTAAAGGCCGTAA-3'
c. 5'-TATAATAAACGCGCAAA-3'
d. 5'-GTAACTCCACGAAGTAA-3'
90. It has been suggested that persons heterozygous for cystic fibrosis may have an advantage over homozygous normal persons. This suggestion is based on the fact that
a. heterozygotes live longer.
b. cystic fibrosis occurs at such a high rate among some populations.
c. there are several other diseases very much like cystic fibrosis in which heterozygotes do have a selective advantage.
d. the distribution of genotypes follows the Hardy-Weinberg law.
91. There was a major mammalian radiation about 65 million years ago. This was characterized by
a. formation of most of the present-day mammalian groups.
b. near extinction because of intense cosmic rays.
c. elimination of all but the best adapted mammalian species.
d. a population explosion of the earliest mammalian progenitor.
92. According to recent studies, the apes closest to humans in evolution are the
a. gorillas.
b. chimpanzees.
c. orangutans.
d. gibbons.
93. Humans resemble the great apes very closely in
a. chromosome banding.
b. bipedalism.
c. brachiation.
d. structure of the pelvis.
94. Upright posture (bipedal locomotion) among our fossil ancestors can be recognized by
a. position of entry of the spinal cord into the skull.
b. position of the heart.
c. the number of vertebrae.
d. the relative length of the arms and legs.
95. The genus that preceded Homo in the evolutionary line was
a. Sivapithecus.
b. Australopithecus.
c. Homeopithecus.
d. Africanopithecus.
96. Which of the following evolutionary sequences is correct?
a. Homo neanderthalensis—>H. habilis—>H. erectus
b. H. habilis—>H. erectus—>H. neanderthalensis
c. H. erectus—>H. habilis—>H. sapiens
d. H. neanderthalensis—>H. sapiens—>H. erectus
97. It has been suggested that humans will evolve to a more neotenic form. This means that they will
a. have shorter arms and legs.
b. have larger hands.
c. have smaller and weaker muscles.
d. be more child-like in development and appearance.
98. The predominant theory on origin of modern humans is that
a. they evolved in parallel in a number of separated populations of Neanderthals.
b. they evolved as a single population in Africa.
c. they evolved as a single population in Asia.
d. they are a hybrid population between Neanderthal and late populations of Homo erectus.
99. During much of human existence, gene frequencies often changed because of
a. founder effect.
b. assortative mating.
c. inbreeding.
d. balanced polymorphism.
100. The close genetic relationship of Native Americans to Asians is supported by
a. shared chromosomal banding patterns.
b. position of the foramen magnum.
c. similar sexual dimorphism.
d. allele frequencies of several polymorphic loci.
last revision: 7 December 1999
owned by:
Dr. Eldon Sutton