Download Biol 178 Exam4 Study Guide – DNA and Molecular

Biol 178
Exam4 Study Guide – DNA and Molecular Genetics.
The questions below are representative of those you can expect on the next exam scheduled for
Wednesday, November 15, 2006.
1. _____ are viruses that attack bacteria.
2. ___ is the genetic material for all cellular organisms and some viruses.
3. Nucleotides have phosphates attached at the ___ carbon atom of the sugar.
4. Watson and Crick developed a model of DNA in which the two strands twist into the shape of a ________.
5. The Watson-Crick model suggested that the genetic information was copied into RNA in a ____
fashion.
6. Since both the strands of a DNA molecule are complimentary to each other, either one of the strands
can be used as a _______ to reconstruct the other.
7. The synthesis of the growing chain of DNA is carried out by adding nucleotides to the ___ end.
8. The units of hereditary information are called _____.
9. In general, the nucleotide sequence in DNA specifically corresponds to _____ ____ sequences of
proteins.
10. The connection that exists between hereditary traits and genes requires the deciphering of the
information encoded in genes into
A) amino acids
B) nucleotides
C) proteins
D) histone molecules
E) complementary bases
11. Both DNA and RNA are made up of building blocks known as
A) nucleotides
B) complementary base pairs
C) amino acids
D) genes
12. DNA consists of two antiparallel strands of nucleotide chains held together by
A) peptide bonds
B) polar covalent bonds
C) ionic bonds
D) hydrogen bonds
E) complementary base pairing bonds
13. The method of DNA replication, where each original strand is used as a template to build a new
strand, is called the
A) conservative method
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B)
C)
D)
E)
semiconservative method
disruptive method
continuous method
replication and amplification method
14. The enzyme that catalyzes the synthesis of new DNA molecules is called
A) DNA ligase
B) DNA polymerase
C) RNA polymerase
D) RNA ligase
E) tRNA primase
15. A direct test of the hypothesis that the nucleus is the repository of genetic information was carried
out by Briggs and King. When they removed the nucleus from a frog's egg and replaced it later with the
nucleus from a more advanced frog embryo cell,
A) it was digested away before developing into an adult frog
B) the egg never developed into a frog
C) the egg developed into a frog
D) the nucleus became independent of cytoplasm
E) it survived only if the replacing nucleus was bigger
16. All of the following scientists' experiments contributed to the conclusion that with rare exceptions,
the nuclei of all eukaryotic cells contain a full complement of genetic information, except
A) Hammerling
B) Gurdon
C) Steward
D) Briggs and King
E) Griffith
17. Griffith worked with
A) Acetabularia
B) Drosophila
C) frog eggs
D) Pneumococcus
E) carrot tissue
18. When nonvirulent bacteria were mixed with dead virulent bacteria, Griffith unexpectedly found that
the injected mice died. He explained this behavior by suggesting the nonvirulent strain of bacteria as
being
A) activated
B) transformed
C) translated
D) transcribed
E) expressed
19. Avery and his coworkers showed the “transforming principle” as
A) protein
B) polysaccharide
C) DNA
D) RNA
E) lipid
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20. Which of the following statements are true in the Hershey-Chase experiment?
A) DNA was labelled with radioactive phosphorus.
B) Protein was labelled with radioactive sulfur.
C) The virus-infected bacteria showed radioactive phosphorus.
D) The virus-infected bacteria contained radioactive sulfur.
E) only a, b, and c
21. As the two strands of DNA are unraveled, an enzyme relieves the strain on the two strands. The
enzyme is
A) DNA polymerase
B) DNA ligase
C) DNA gyrase
D) RNA polymerase
E) RNA ligase
22. Which of the following are components of nucleic acids?
A) organic nitrogen bases
B) sugar
C) phosphate
D) choices a and b
E) choices a, b, and c
23. The reading of the bases along the length of a nucleic acid molecule for either transcription or
translation is done from the
A) 1' end
B) 2' end
C) 3' end
D) 4' end
E) 5' end
F) at any point
24. The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is
called a
A) C = C bond
B) hydrogen bond
C) hydrophobic bond
D) phosphodiester bond
E) peptide bond
25. Chargaff's rules for the pairing of nitrogen bases is
A) A = C and G = T
B) A pairs with T and G pairs with C
C) A pairs with G and C pairs with T
D) A pairs with C and G pairs with T
E) T = C and G = A
26. Information obtained by Franklin from X-ray crystallography on DNA suggested that it is a
A) helix
B) ribbon
C) hollow cylinder
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D) pleated sheet
E) icosahedron
27. The chemical bonds that stabilize the complimentary nitrogen bases into a double helix are
A) C = C bonds
B) hydrogen bonds
C) hydrophobic bonds
D) peptide bonds
E) phosphodiester bonds
28. Replication of DNA is
A) conservative
B) redundant
C) dispersive
D) semiconservative
E) semidispersive
29. The lagging strand is replicated with stretches of Okazaki fragments and that is why its synthesis is
considered to be
A) discontinuous
B) continuous
C) primed
D) never stopping
E) semiconservative
30. Replication always proceeds by adding new bases to the
A) 1' end
B) 2' end
C) 3' end
D) 4' end
E) 5' end
31. Which of the following are true about replication of DNA?
A) The two strands are separated.
B) Each strand is used as a template for making a new duplex.
C) The synthesis on each strand is in the opposite direction.
D) The newly synthesized DNA is packaged into one nucleus, and the old DNA is packaged
into another nucleus.
E) choices a, b, and c
32. Which of the following is not true about eukaryotic DNA?
A) It is an exceedingly long and fragile molecule.
B) It is packaged into successively compact formations.
C) The entire molecule has encoded information for protein synthesis.
D) In the condensed form, it is transcriptionally inactive.
E) It must be unpackaged before it can be transcribed into RNA.
33. The double helix model was proposed by
A) Watson and Crick
B) Griffith
C) Avery
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D) Franklin
E) Beadle and Tatum
34. Fourteen percent of the DNA nucleotides from a certain organism contain T. What amounts of the
other bases would you expect to be present in this particular DNA?
A) 14 % A, 0% C, 36 % G
B) 14 % A, 36 % C, 14 % G
C) 14 % A, 36 % C, 36 % G
D) 14 % T, 38 % C, 36 % G
E) 14 % T, 36 % C, 36 % U
35. DNA and RNA nucleotides are composed of five carbon sugars, phosphate and nitrogen bases. How
many total nitrogen bases are there for use in the two nucleic acids?
A) 2
B) 3
C) 4
D) 5
36. If a short sequence of DNA is AATTGCCGT, its complement is
A) AAAACGCCA
B) TTAACGGCT
C) TTAACGGCA
D) TTAAGCCGA
37. When DNA is replicated during S of the cell cycle, the sequence is maintained but the double strand
is not. Each strand of the original double strand accompanies its new complement strand. This process is
known as the
A) disruptive DNA replication
B) conservative DNA replication
C) semiconservative DNA replication
D) dispersive DNA replication
E) stabilizing DNA replication
38. A scientist developed a procedure that would cause a particular chemical to bind with the nitrogen
base adenine. If this chemical were applied prior to S in the cell cycle, what might be a logical
prediction of the outcome?
A) The DNA replication would proceed except that all adenine would have the chemical
bound to it and is incorporated into the new sister chromatids.
B) The DNA replication would proceed except that everywhere an adenine was supposed to
be, a thymine was substituted into the new developing strand.
C) The DNA replication would proceed except cytosine and guanine would continue to form
base pairs.
D) The DNA replication would stop because if adenine were bound then thymine would not
have a complement with which to base pair.
39. Which of the following DNA replicating enzymes is responsible for unwiding the double helix of
DNA?
A) DNA primase
B) DNA polymerase I
C) DNA helicase
D) DNA gyrase
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E) DNA ligase
40. Which of the following choices is the correct sequence for DNA replication in E. coli?
A) initiation, termination, elongation
B) initiation, elongation, termination
C) elongation, termination, initiation
D) elongation, initiation, termination
41. Enzymes that cleave DNA at specific sites are called ________.
42. The procedure for producing a line of genetically identical cells from a single “altered” cell is called
_________.
43. Single-stranded complementary tails that are produced by restriction digestion are called ______
ends.
44. Viruses and bacterial plasmids are used as ______ to insert foreign DNA into host cells and create
recombinant genomes.
45. Gel _________ is a process that separates DNA or protein fragments according to their size, by
causing them to migrate within a gel in response to an electric field.
46. In addition to bacteria, _______ can also be used as vectors to insert foreign DNA into host cells and
create recombinant genomes.
47. DNA can be cleaved at a specific site, generating in most cases two fragments with short singlestranded ends. The chemical tool used to cleave the DNA is called
A) a hybridization enzyme
B) a complementary enzyme
C) a restriction enzyme
D) a methylating enzyme
E) an endonuclease
48. Since the single stranded ends created by restriction enzymes are complementary to each other, they
can be joined together,
A) even though the source of the DNA is different
B) even though the source of the DNA is the same
C) but the “sticky ends” will most likely have to be modified
D) but the hybridization of the two ends may cause a problem with cloning
E) only if the subunits have been methylated
49. Two strands of DNA that have been cut by an endonuclease can be sealed together by
A) a polymerase enzyme
B) a ligase enzyme
C) an exonuclease enzyme
D) a protease enzyme
E) a methylase enzyme
50. Restriction enzymes are
A) proteases
B) lipases
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C) endonucleases
D) exonucleases
51. An enzyme that has been isolated from retroviruses is
A) transverse ligase
B) reverse transcriptase
C) reverse endonuclease
D) recombinant RNAase
E) RNA polymerase
52. The ends of DNA fragments produced by the same restriction enzyme can be joined together by
another enzyme,
A) DNA polymerase
B) DNA methylase
C) DNA synthetase
D) DNA ligase
E) DNA primase
53. Most genetic engineering experiments include four stages. Which of the following is not one of
them?
A) cleaving the source DNA
B) production of recombinant DNA
C) cloning copies of the recombinanats
D) screening the cloned copies for the desired gene
E) integration of the entire bacterial chromosome
54. The polymerase chain reaction, more popularly known as PCR, includes which of the following
steps?
A) denaturation of primers and the DNA fragment to be amplified
B) anealing of primers to the complementary sequences on the DNA
C) primer extension with DNA polymerase
D) repeating steps 1-3 in many cycles
E) all of the above
55. In genetic engineering experiments, a common way of identifying a transformed cell is by using a
“probe,” which is
A) a specific complimentary double stranded DNA
B) a specific complimentary double stranded RNA
C) a specific complimentary single stranded DNA
D) a specific complimentary single stranded RNA
E) none of the above
56. When electrical current is applied during a gel electrophoresis procedure, the DNA fragments are
separated by
A) electrical charge, positive on one side, negatives on the other
B) the number of poly A tails associated with each one
C) their response to the staining chemicals used during the procedure
D) the size of the fragments
E) the enzyme binding activity sites
57. A commercially significant human protein now produced in bacteria is
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A)
B)
C)
D)
E)
hemoglobin
gamma globulins
AZT
human insulin
HIV vaccine
58. A plasmid used to carry genes into crop plants is
A) Ti
B) glyphosphate
C) somatotropin
D) recombinant DNA
E) Roundup
59. Scientists can distinguish between DNA of different individuals, thus making this information useful
in criminal investigations. The technique used is called
A) restriction fragment length polymorphisms
B) gene cloning
C) hybridization polymorphisms
D) Southern Blot
E) genetic engineering
60. Some of the useful applications of genetic engineering include all of the following except
A) bacteria that can digest oil in an oil spill
B) growing synthetic cotton
C) manufacturing biopolymers
D) using PCR to study ancient fossils
E) to clone the perfect human being
61. Mutations and recombinations are two ways in which DNA can be altered. They are different in that
A) mutations are an actual change in the base sequence of a gene, whereas a recombination is a
change in the position of a portion of the genetic message
B) mutations are an actual change in the position of a portion of the genetic message, whereas
a recombination is a change in the base sequence of a gene
C) mutations occur because of radiation exposure, while recombination occurs as a result of
genes being rearranged because of the radiation
D) mutations result from recombinations within the nucleotides
62. Mutations can be harmful, helpful, or neutral. Natural selection acts on these mutations and selects
for the mutation or against the mutation. Thus, organisms that have a mutation that is selected will have
their fitness increased, while organisms that have mutations that are selected against will have their
fitness decreased. Exactly what is natural selection acting on in the selection process?
A) Natural selection is acting on the DNA directly.
B) Natural selection is acting on the phenotype, which is an expression of the genotype.
C) Natural selection is acting on the genotype directly and therefore not the phenotype.
D) Natural selection is seeking the correct allele combinations so that the species may prosper
into the future.
63. Golden rice was genetically engineered by Ingo Potrykus in Switerland by combining genes from
other organisms into the genome of common white rice. Which organism from the list below was NOT
used?
A) daffodil
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B)
C)
D)
E)
wild rice
beans
Agrobacterium
Aspergillus
64. A _____ is all of the DNA in a nucleus of a cell.
65. Mobile bits of DNA that can jump from one location on a chromosome to another location are called
A) simple sequence repeats
B) transposons
C) exons
D) introns
E) pseudogenes
66. A transgene is
A) hard to destroy once inserted into a genome
B) hard to study because of its transpons
C) created by several of the DNA motifs
D) an inserted foreign gene
E) a result of endosymbiosis
67. Non-coding DNA regions within a gene are referred to as
A) introns
B) exons
C) templates
D) transposons
E) pseudogenes
68. Homologous regions of DNA can vary slightly in base-pair composition among individuals in a
population. When a homologous stretch of DNA is cut with restriction enzymes in different individuals,
fragments of different lengths are produced. These fragments are called
A) landmarks of DNA sequencing
B) contig fragments
C) single length polymorphisms
D) restriction fragments length polymorphisms
E) sequence-tagged site fragments
69. PCR products are separated on a DNA gel based on
A) ionic charge of the product (i.e., if it positively or negatively charged)
B) methylated side chains on the products
C) the number of contigs available
D) amount of electrical voltage in the current applied to the gel
E) size of the products
70. The most common form of regulation in bacteria and eukaryotes is
A) transcripitional control
B) translational control
C) promotor control
D) repressor control
E) operator control
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71. Regulatory proteins shut off transcription by binding to a site immediately in front of the promoter
and often even overlapping the promotor. This site is referred to as
A) the suppressor site
B) the operator site
C) the repressor site
D) the regulatory site
E) the transcriptional control site
72. The basic tool of genetic regulation is the ability of certain proteins to bind to specific
A) regulatory RNA sequences
B) regulatory DNA sequences
C) repressor parts of the gene
D) promoter parts of the gene
E) enzymes of the cell
73. RNA polymerase binds to a site on DNA called the
A) operator
B) repressor
C) footprint
D) promoter
E) operon
74. In gene regulation, negative control is exerted by
A) an activator
B) an operon
C) a promoter
D) a regulator
E) a repressor
75. A bacterial gene regulatory system is likely to have all of the following except
A) a coding sequence
B) an operator
C) a promoter
D) one or more introns
E) a ribosome recognition site
76. Which of the following must happen for transcription to be initiated?
A) DNA polymerase must have access to the DNA double helix and also must be capable of
binding to the gene's promoter.
B) RNA polymerase must have access to the DNA double helix and also must be capable of
binding to the gene's promoter.
C) DNA polymerase must have access to the RNA and also must be capable of binding to the
gene's promoter.
D) DNA ligase must have access to the DNA double helix and also must be capable of binding
to the gene's promoter.
E) DNA kinase must have access to the DNA double helix and also must be capable of
binding to the gene's promoter.
77. Most eukaryotic genes are composed of exons (short coding sequences) and introns (non-coding
sequences). Which of the following statements is correct regarding the primary transcript?
A) The primary transcript is composed of RNA polymerase and associated histones.
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B)
C)
D)
E)
The primary transcript has the exons removed and the introns retained for translation.
The primary transcript is a faithful copy of the entire gene including exons and introns.
The primary transcript is a faithful copy of the gene, but the introns have been removed.
The primary transcript is a faithful copy, but the exons have been removed.
78. Small circular, extrachromosomal DNA segments are known as ________.
79. The agents such as radiation and chemicals that cause changes in the DNA base sequence are called
_________.
80. Genes that can be mutated and thus produce tumor forming genes are referred to as ________.
81. Genes that encode for proteins that prevent cyclins from binding to Cdk's are called _______.
82. If a cancer cell breaks loose it can spread to other parts of the body and begin secondary tumors.
This is called _________.
83. A change in the content of the genetic message is called
A) transposition
B) mutation
C) germ line translocation
D) cross-over
E) transfection
84. In both bacteria and eukaryotes, individual genes may move from one place to another in the DNA
by a process called
A) transcription
B) translation
C) transfection
D) transference
E) transposition
85. Mutations that occur in these types of cells are not passed on to the next generation.
A) egg cells
B) sperm cells
C) germ-line cells
D) somatic cells
86. When a segment of one chromosome becomes part of another chromosome, this is called a
A) conformation
B) frameshift
C) translocation
D) deletion
E) inversion
87. Small, circular auxiliary DNA molecules of bacteria which are commonly used in genetic
engineering technology are referred to as
A) transposons
B) germ-line DNA molecules
C) plasmids
D) conformational DNA molecules
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E) translational DNA molecules
88. Mutations that consist of a change in one or a few nucleotides of a DNA sequence are called
A) cancer-causing mutations
B) chromosomal rearrangements
C) double-strand breaks
D) point mutations
E) somatic mutations
89. One of the most significant causes of mutation involves transposons, which cause
A) insertional inactivation
B) inversion
C) deletion
D) transfection
E) plasmid transfer
90. If a mutation occurs in a somatic cell, it passes to
A) germ-line cells
B) the gametes
C) all descendents of that cell
D) the zygote
E) only the neighboring cells
91. Normal genes that have gone awry and now cause cancer are the
A) DNA viruses
B) growth-promoter genes
C) oncogenes
D) retroviruses
E) tumor viruses
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