Zoo 317: Heredity, Evolution and Society
Fall 1999
Exam II from Fall 1998
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These questions, administered in Fall 1998, covered the same material as the second exam to be given in Fall 1999. None of the questions is likely to appear on the 1999 exam. However, IF you can answer all of them, you should do very well on the 1999 exam.
Remember to bring a photo ID to class. You will need it to turn in your exam. |
Mark the correct answer on the separate answer sheet with a #2 pencil. On the answer sheet, be sure to (1) print your name, (2) code your name, (3) enter your SSN, (4) code your SSN, (5) sign with your usual signature. There is one best answer for each question. Other answers may be partially correct but not in all circumstances. If you must erase, do so thoroughly so that the machine will not misread your intentions. Answer sheets must be turned in no later than 9:50. You may keep the exam. The answer key will be posted outside the exam room about 9:25.
1. A locus that is polymorphic
a. consists of two or more genes in tandem.
b. has different forms in different tissues.
c. is often associated with polyphagia.
d. has two or more common alleles.
2. One way to reduce the heritability of a trait such as obesity would be to
a. place everyone on a uniform low calorie diet.
b. place everyone on a uniform high calorie diet.
c. place everyone on an unrestricted diet.
d. adjust the calorie intake of everyone so that the measures of obesity for each person are identical.
3. It has been found that elderly MZ twins are more often concordant for the diagnosis of Alzheimer disease than are DZ twins of similar age. This suggests that
a. Alzheimer disease is always inherited.
b. Alzheimer disease is inherited in some persons and in other persons is environmental.
c. Alzheimer disease is never inherited, since some MZ twins are discordant.
d. susceptibility to Alzheimer disease may be inherited but environmental factors may also play a part.
4. The hair color of U.S. whites is highly variable and strongly influenced by heredity. The hair of Asian-Americans is uniformly black. Therefore,
a. heritability of hair color is greater in Asian-Americans than in whites.
b. since the phenotype is uniform in Asians, the concept of heritability has no meaning.
c. Asians must be homozygous at all loci that affect hair color.
d. heritability of hair color in whites would be reduced if the environment were uniform.
5. Heart disease is greater among Japanese who grew up in Hawaii than in their parents who grew up in Japan. The most likely explanation for this difference is
a. the Hawaiian environment increases risk of heart disease relative to Japanese environment.
b. there is no genetic predisposition to heart disease; it's all environment.
c. the immigrants to Hawaii had an unusually high frequency of genes that cause heart disease.
d. the immigrants were more likely to survive other causes of death and therefore more likely eventually to develop heart disease.
6. The process of fertilization generally occurs in
a. the seminiferous tubules.
b. the epididymis.
c. the ductus deferens.
d. the fallopian tubes.
7. In parthenogenetic ovarian teratomas,
a. the genes and the cytoplasm are maternal in origin.
b. the genes are maternal but the cytoplasm is paternal.
c. the genes are paternal but the cytoplasm is maternal.
d. the genes and the cytoplasm are paternal.
8. In vitro fertilization is sometimes used when a husband and wife are both heterozygous for a detrimental trait because
a. the detrimental allele can be replaced.
b. the pregnancy can be established in a surrogate mother.
c. the early embryo can be tested genetically before a decision is made to implant it.
d. the influence of teratogens can be tested before implantation.
9. The use of "fertility pills" increases the likelihood of multiple births by causing
a. splitting of early embryos.
b. improving chances of implantation in the endometrium.
c. reducing spontaneous abortions.
d. increasing multiple ovulation.
10. In mammals, the embryo develops from
a. the trophoblast.
b. the interstitial cells.
c. the inner cell mass.
d. the Barr body.
11. Development of the embryonic gonad into a testis results from
a. presence of only one X chromosome.
b. presence of an SRY gene.
c. presence of sex chromatin.
d. presence of androgen.
12. If the Wolffian ducts are stimulated to develop, the individual is most likely
a. normal male.
b. normal female.
c. an XY female.
d. a female pseudohermaphrodite.
13. Persons with androgen insensitivity are
a. XX males.
b. XY females.
c. XXY males.
d. females before puberty; males after.
14. In X-chromosome inactivation,
a. the presence of testosterone in males causes many genes on the X chromosome to be inactive.
b. genes on the Y chromosome are expressed in preference to genes on the X chromosome.
c. genes on the X chromosome are inactive except in the ovaries.
d. there is only one fully active X chromosome in each cell.
15. A sex-limited trait is one that
a. influences only sexual characteristics, such as genitalia.
b. is transmitted only by one sex.
c. is expressed only in one sex.
d. is transmitted only by sex chromosomes.
16. Which of the following elementary particles are found in atomic nuclei?
a. protons and neutrons
b. electrons and mesons
c. protons and electrons
d. neutrons and electrons
17. When two atoms share a pair of electrons, the resulting attraction between the atoms is called
a. a covalent bond.
b. an electron bond.
c. a hydrogen bond.
d. an ionic bond.
18. When an electrically neutral atom loses an electron, it becomes
a. an isotope.
b. an anion.
c. a cation.
d. a scion.
19. What is the maximum number of hydrogen atoms that can form covalent bonds with one carbon atom?
20. The nucleotide building blocks of nucleic acids are composed of
a. a purine or pyrimidine base, cholesterol, and phosphate.
b. a purine or pyrimidine base, a sugar, and phosphate.
c. an amino acid, a sugar, and phospate.
d. an amino acid, cholesterol, and phosphate.
21. The nucleotides of DNA are represented by A, G, T, and C. Those of RNA are represented by
a. A, G, T, and U.
b. A, G, U, and C.
c. A, U, T, and C.
d. U, G, T, and C.
22. The two DNA strands of a Watson-Crick double helix are held together by
a. covalent bonds.
b. ionic bonds.
c. hydrophilic bonds.
d. hydrogen bonds.
23. The two DNA strands of a Watson-Crick double helix are described as complementary because
a. they contain different information.
b. they are structurally identical.
c. a base on one strand will pair only with one specific base on the other strand.
d. one is 5' —> 3', the other is 3' —> 5'.
24. Genetic information is stored in the sequence of nucleotides. For a DNA strand of 4 nucleotides, how many different sequences could exist?
a. 32
b. 128
c. 256
d. 1024
25. The enzyme that catalyzes DNA replication is called
a. DNA polymerase.
b. DNA replicase.
c. DNA synthetase.
d. DNA nuclease.
26. A peptide bond joins together
a. an amino acid and a tRNA.
b. two amino acids.
c. the consecutive turns of a polypeptide helix.
d. two polypeptides.
27. A particular DNA template strand sequence is 3'-CTGGAGA-5'. When transcribed, the new sequence would be
a. 3'-GACCTCT-5'.
b. 3'-CUGGAGA-5'
c. 5'-GUCCTCT-3'.
d. 5'-GACCUCU-3'.
28. During the processing of messenger RNA in the nucleus,
a. exons are removed.
b. introns are removed.
c. exons are inserted.
d. introns are inserted.
29. During the synthesis of a protein, the information for its structure comes
a. only from messenger RNA.
b. from both messenger RNA and ribosomal RNA.
c. from both messenger RNA and transfer RNA.
d. from both messenger RNA and small nuclear RNA.
30. The total number of different amino acids coded by genes is
a. 3.
b. 20.
c. 61.
d. 64.
31. The number of nucleotides in a codon is
a. 1.
b. 3.
c. 20.
d. 64.
32. Which statement best describes the true situation?
a. The genetic code is similar among eukaryotes but differs from that of prokaryotes.
b. Each species has its unique genetic code.
c. The initiation codon is identical in all species, but other codons vary considerably.
d. All living forms of life use the same genetic code.
33. During translation, the reading frame is established by
a. the messenger RNA cap.
b. DNA polymerase.
c. the initiation codon.
d. the messenger RNA poly-A tail.
34. Phenylketonuria is an example of
a. an inborn error of metabolism.
b. anticipation.
c. a defect in a transcription factor.
d. a neuroreceptor defect.
35. The detrimental effects characteristic of persons homozygous for PKU can be prevented by
a. consumption of Nutrasweet.
b. avoidance of lactose.
c. regulation of dietary protein.
d. drugs that enhance neurotransmission.
36. Some persons with PKU have two different defective alleles. They are called
a. genomorphs.
b. dizygotic.
c. phenocopies.
d. compound heterozygotes.
37. Persons with sickle cell trait
a. cannot transport oxygen efficiently.
b. have severe anemia because of ruptured red blood cells.
c. are unable to make sufficient hemoglobin for normal red cell function.
d. are phenotypically normal.
38. Functional LDL receptors are necessary to
a. transport LDL from the blood into liver cells.
b. avoid Tay-Sachs disease.
c. breakdown lactose in the gut.
d. transport androgens into the nucleus.
39. Abraham Lincoln is thought to have had Marfan syndrome, which is a defect in
a. an enzyme.
b. a structural protein.
c. a transcription factor.
d. growth hormone.
40. The SRY gene product appears to be a transcription factor. This means that
a. it modifies the amount of RNA produced by certain genes.
b. it influences the rate of processing of certain kinds of RNA.
c. it catalyzes the assembly of RNA.
d. it facilitates release of androgens into the blood stream.
41. Which statement is correct?
a. Germinal mutations are those that interfere with embryonic development.
b. Somatic mutations caused by exposure to environmental mutagens can be transmitted to offspring.
c. Only mutations that arise in germ cells are potentially transmissible to offspring.
d. Under certain circumstances, both somatic and germinal mutations are transmitted to offspring.
42. The mutation rate for aniridia (absence of iris of the eyes), an autosomal dominant trait, is ca. 4 per million gametes. What would be the frequency of children with this disorder due to a new mutation in one of their parental gametes?
a. 1 per million
b. 2 per million
c. 4 per million
d. 8 per million
43. A mutant allele is found to have an extra nucleotide inserted into the coding region. This would cause
a. substitution of a single amino acid in place of the original at that point in the polypeptide.
b. premature termination of the polypeptide.
c. a shift in the reading frame.
d. insertion of an additional amino acid at that point in the polypeptide.
44. Mutations in the noncoding DNA region that flanks the 5' end of the coding region
a. have no effect on gene function.
b. may influence the amount of gene product formed.
c. affect both the amount and kind of gene product formed.
d. typically affect the kind but not amount of gene product formed.
45. The high mutation rate of the fragile-X syndrome (the FMR1 gene) is due to
a. trinucleotide expansion.
b. deletions.
c. frameshift mutations.
d. mobile elements.
46. A "genetically significant dose" of radiation is
a. the radiation that exceeds the mutational threshold.
b. the radiation that reaches the gonads.
c. the radiation that reaches the gonads multiplied by the age of the person.
d. the radiation that reaches the gonads multiplied by the likelihood of subsequent children.
47. Ultraviolet light causes mutations in skin cells but not bone marrow because
a. only skin cells have UV receptors.
b. bone marrow cells are very resistant to mutation.
c. UV cannot penetrate to the bone marrow.
d. UV does not cause ionization when it passes through bone marrow.
48. One can never avoid all radiation to the body because
a. all chemical elements are radioactive.
b. the body itself produces radioactive elements.
c. an adequate shield would have to be of infinite thickness.
d. the potassium includes an isotopic form that is radioactive.
last revision: 12 October 1999
owned by:
Dr. Eldon Sutton