Zoo 317: Heredity, Evolution and Society
Fall 1998
Exam 2 from Fall 1997
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This exam, administered in Fall 1997, covered the same material as the second exam to be given in Fall 1998. None of the questions that appear below will appear on the 1998 exam. However, If you can answer all the questions on the 1997 exam, you should do very well on the 1998 exam.
Reminder: Bring a to class. You will need it to turn in your exam. |
Mark your answer on the separate answer sheet with a #2 pencil. Be sure to code in your name and SSN and sign the answer sheet with your usual signature. Exams are due no later than 9:50. Please present a photo ID when you turn in your exam.
1. The risk of nondisjunction is highest in which of the following paternal decades?
a. Twenties.
b. Thirties.
c. Forties.
d. None of these; it is independent of paternal age.
2. One feature of Down syndrome is the high risk associated with
a. maternal smoking.
b. German measles during pregnancy.
c. use of certain drugs by the father.
d. advanced age of the mother.
3. Trisomy 21 is an example of
a. triploidy.
b. euploidy.
c. aneuploidy.
d. polyploidy.
4. Embryos that are triploid most often arise by
a. endoreduplication in the fertilized egg.
b. nondisjunction.
c. fertilization of a polar body.
d. fertilization by two sperm.
5. Amniocentesis for prenatal diagnosis is best done at
a. 6-8 weeks of gestation.
b. 8-10 weeks of gestation.
c. 14-16 weeks of gestation.
d. 22-30 weeks of gestation.
6. When part of a chromosome is deleted, abnormality may result because
a. chromosomes cannot segregate in meiosis.
b. crossing over is suppressed.
c. recessive genes in that portion of the nondeleted homologous chromosome are expressed.
d. crossing over in that region generates duplications and deficiencies.
7. Some cases of Down syndrome are caused by an unbalanced
a. translocation.
b. inversion.
c. synapsis.
d. deletion.
8. The XYY syndrome commonly arises by
a. polyploidy.
b. nondisjunction.
c. gynandromorphism.
d. misogyny.
9. In Huntington disease, the age of onset is earlier when the mutant gene is transmitted by males. This is called
a. precession.
b. anticipation.
c. premature expression.
d. neotropism.
10. Persons with Turner syndrome are
a. XXY females.
b. XY females.
c. XO females.
d. XO males.
11. During embryonic development, secretions of the testes cause
a. development of the Wolffian and Mullerian ducts.
b. inhibition of the Wolffian and Mullerian ducts.
c. development of the Wolffian and inhibition of the Mullerian ducts.
d. inhibition of the Wolffian and development of the Mullerian ducts.
12. Mullerian inhibitor normally prevents the embryonic development of
a. fallopian tubes, uterus, and part of the vagina in females.
b. fallopian tubes, uterus, and part of the vagina in males.
c. seminal vesicles and vas deferens in females.
d. seminal vesicles and vas deferens in males.
13. Which of the following is essential for development of male genitalia in humans?
a. Androgen.
b. Estrogen.
c. Progesterone.
d. Mullerian inhibitor.
14. In androgen resistance (testicular feminization),
a. XY persons with testes develop female phenotypes.
b. XY persons with ovaries develop female phenotypes.
c. XX persons with testes develop male phenotypes.
d. XX persons with ovaries develop male phenotypes.
15. The principal locus in the determination of normal male vs female development is
a. the SXY gene in the pseudoautosomal region.
b. the SEX gene on the long arm of the Y chromosome.
c. the SRY gene on the short arm of the Y chromosome.
d. the TST gene on the short arm of the X chromosome.
16. Fertilization of an ovum generally occurs
a. in the ovary.
b. in the fallopian tube.
c. in the uterus.
d. in the vagina.
17. X-chromosome inactivation refers to
a. dominance of the Y chromosome over the X chromosome.
b. lack of activity of genes on the X chromosome in males.
c. having only one active X chromosome in cells of females.
d. the development of XX embryos as males.
18. In methane, the single carbon atom has the maximum number of covalent bonds with hydrogen. What is the number of atoms of hydrogen bound to the carbon?
19. Which of the following chemical bonds is the strongest?
a. Ionic.
b. Covalent.
c. Hydrogen.
d. Hydrophobic.
20. When a neutral atom gains or loses electrons, it becomes
a. a positron.
b. an ion.
c. a proton.
d. a lipid.
21. Most of the mass of an atom is due to
a. electrons.
b. protons.
c. neutrons.
d. protons + neutrons.
22. Because of specific pairing between nucleotides of the two DNA strands, the strands are described as
a. covalent.
b. coordinate.
c. complementary.
d. bipolar.
23. Which of the following are components of a nucleotide of DNA?
a. deoxyribose, phosphate, and amino acid.
b. ribose, phosphate, and amino acid.
c. deoxyribose, phosphate, and base.
d. ribose, phosphate, and base.
24. In eukaryotic cells, DNA is wrapped around histones to form
a. nucleosomes.
b. histiocytes.
c. chromomeres.
d. histomeres.
25. Which of the following nucleotides (symbolized by the initial letter) is found in RNA but not in DNA?
26. The enzyme that catalyzes DNA replication is known as
a. DNA synthase.
b. DNA polymerase.
c. DNA nucleotidase.
d. DNA templase.
27. The structure of amino acids includes
a. amino groups at each end.
b. carboxyl groups at each end.
c. two amino groups separated by a carboxyl group.
d. an amino group at one end and a carboxyl group at the other.
28. The transfer of genetic information from DNA to RNA is called
a. transference.
b. transcription.
c. translation.
d. translocation.
29. Coding regions of most eukaryotic genes are interrupted by noncoding regions called
a. antisense sequences.
b. primers.
c. tandem repeats.
d. introns.
30. A codon is the unit of genetic information that specifies
a. the initiation of protein synthesis.
b. one amino acid in a protein.
c. the complete structure of one protein.
d. the activation of a particular gene.
31. The synthesis of proteins occurs on
a. ribosomes.
b. lysosomes
c. LDL receptors.
d. protoplasts.
32. The reading frame is established by
a. the site of initiation of transcription.
b. the first splice site.
c. the initiation codon.
d. the termination codon.
33. Hemoglobin is an example of
a. an enzyme that catalyzes oxygen use.
b. a receptor protein that is activated by oxygen.
c. a transport protein that carries oxygen to various tissues.
d. a hormone that regulates cellular use of oxygen.
34. Many proteins are known that function as gene regulators. These are called
a. transcription factors.
b. endonucleases.
c. RNA polymerases.
d. exonucleases.
35. Children who are homozygous for PKU can develop normally if
a. they are given adequate external stimuli.
b. they are maintained on psychogenic drugs.
c. milk is eliminated from their diet.
d. phenylalanine is restricted in their diet.
36. Enzymes function in biological systems as
a. structural elements.
b. hormones.
c. catalysts.
d. sources of energy.
37. Avoidance of milk is an effective treatment for
a. galactosemia.
b. Tay-Sachs disease.
c. Lesch-Nyhan syndrome.
d. Marfan syndrome.
38. The term "inborn error of metabolism" refers to
a. block of an enzyme by a drug metabolite.
b. failure in the splicing mechanism.
c. production of developmental defects by normal enzymes.
d. inherited defects due to absence of a specific enzyme.
39. An inherited defect in the LDL receptor is associated with high blood levels of cholesterol. The high levels of cholesterol result from failure to
a. regulate synthesis of cholesterol in the cells.
b. regulate absorption of cholesterol from the intestine.
c. break down cholesterol.
d. excrete cholesterol normally.
40. Some hormones are directly coded by genes. An example is
a. testosterone.
b. insulin.
c. lactose.
d. collagen.
41. The mutation that gives rise to sickle cell hemoglobin is
a. a missense mutation.
b. a translocation.
c. a nonsense mutation.
d. a deletion.
42. Somatic mutations in humans
a. are not transmitted to offspring.
b. are responsible for the different functions associated with different tissues.
c. are responsible for X-chromosome inactivation.
d. occur only on autosomes.
43. Many DNA changes do not result in mutations because
a. the chromosome on which they occur is eliminated.
b. they are expressed only when homozygous.
c. they are repaired.
d. they are removed by crossing over.
44. Persons with xeroderma pigmentosum have a defect in
a. DNA repair.
b. DNA replication.
c. RNA transcription.
d. RNA translation.
45. The mutation rate for achondroplasia (an autosomal dominant trait) is 1.3 per 100,000 gametes. This means that
a. there are 1.3 cases per 100,000 persons.
b. there are 1.3 cases per 100,000 newborns.
c. there are 2.6 cases per 100,000 newborns.
d. among 100,000 newborns, there are 2.6 cases born to nonaffected parents.
46. The class of mutations known as trinucleotide expansions are characterized by
a. their high mutation rate.
b. production only of frame-shift mutations.
c. interuption of normal splicing.
d. mutation only in somatic tissues.
47. The fragile-X syndrome is
a. a fragile site on the X chromosome that leads to translocations.
b. a condition that causes mental retardation, primarily in males.
c. a condition that causes sterility in females.
d. a result of exposure to ultraviolet light.
Questions 48-50 dealt with topics that will not be on the fall 1998 exam.
last revision: 12 October 1998
owned by:
Dr. Eldon Sutton