Find study materials for any course. Check these out:
Browse by school
Make your own
To login with Google, please enable popups
To login with Google, please enable popups
Don’t have an account?
To signup with Google, please enable popups
To signup with Google, please enable popups
Sign up withor
1. In the 1920s, circumstantial evidence indicated that DNA was the genetic material. Which of the following experiments led to the acceptance of this hypothesis?
a. Griffith’s experiments with Streptococcus pneumoniae
b. Avery, MacLeod, and McCarty’s work with isolating the transforming principle
c. Hershey and Chase’s experiments with viruses and radioisotopes
2. In Griffith’s experiments, when heat-killed S strain pneumococci were injected into a mouse along with live R strain pneumococci,
b. DNA from the heat-killed S was taken up by the live R, converting the latter to S and killing the mouse.
3. Experiments designed to identify the transforming principle were based on
c. selectively destroying the different macromolecules in a cell-free extract.
4. Griffith’s experiment with pneumococcus demonstrated that
c. materials from dead organisms can affect and change living organisms.
5. Griffith was able to distinguish the two strains of pneumococcus by means of
a. the appearance of the colonies in culture.
b. differences in their lethality in mice.
6. In order to show that DNA is the “transforming principle,” Avery, MacLeod, and McCarty showed that DNA could transform nonvirulent strains of pneumococcus. Their hypothesis was strengthened by their demonstration that
b. enzymes that destroy nucleic acids also destroy transforming activity.
7. The Hershey–Chase experiment
d. helped prove that DNA is the genetic molecule.
8. Before the discovery of DNA, the hereditary material was thought to be made of proteins and not nucleic acids because
c. proteins seemed to be much more chemically diverse.
9. The Hershey–Chase experiment persuaded most scientists that
b. DNA is indeed the carrier of hereditary information.
10. During infection of E. coli cells by bacteriophage T2,
d. only nucleic acids enter the cell.
11. Bacteriophage nucleic acids were labeled by carrying out an infection of E. coli cells growing in
c. 32P-labeled phosphate.
12. If Hershey and Chase had found 35S in both the pellet and the supernatant, what would have been their likely conclusion about the nature of DNA replication?
b. No conclusion would have been possible from these results.
13. The Hershey–Chase experiment determined that
d. DNA, not protein, is the hereditary material of viruses.
14. Which of the following molecules functions to transfer information from one generation to the next in eukaryotes?
15. The rules formulated by Erwin Chargaff state that
a. A = T and G = C in any molecule of DNA.
16. Purines include
e. adenine and guanine.
17. Information sources used by Watson and Crick to determine the structure of DNA included
e. X-ray crystallography of double-stranded DNA.
18. If a double-stranded DNA molecule contains 30 percent T, it must contain _______ percent G.
19. The base composition of DNA isolated from a newly discovered virus is found to be 32 percent A, 17 percent C, 32 percent G, and 19 percent T. What would be a reasonable explanation for this observation?
d. The genome of the phage is single-stranded, not double-stranded.
20. The DNA isolated from a newly discovered virus is found to be 32 percent A, 17 percent C, 32 percent G, and 19 percent T. The base composition of the complementary DNA would be _______ percent A, _______ percent C, _______ percent G, and _______ percent T.
b. 19; 32; 17; 32
21. Which feature of the Watson–Crick model of DNA structure explains its ability to function in replication and gene expression?
a. Each strand contains all the information present in the double helix.
22. Chargaff’s rule states that
e. the amount of cytosine equals the amount of guanine.
23. A deoxyribose nucleotide is a
c. deoxyribose plus a nitrogenous base and a phosphate.
25. The structure of the DNA molecule was determined by the experiments of
26. Which of the following molecular models describes the structure of the DNA molecule?
e. Helical, double-stranded, and antiparallel
27. Double-stranded DNA looks a little like a ladder that has been twisted into a helix, or spiral. The side supports of the ladder are
d. alternating sugars and phosphates.
28. The steps of the ladder are
b. pairs of bases.
29. The structure of DNA is characterized by a
b. right-handed double helix and antiparallel strands.
30. The characteristic of DNA that allows it to make an exact copy of itself is its
b. complementary base pairing.
31. The nitrogenous bases (and the two strands of the DNA double helix) are held together by
c. hydrogen bonds.
32. Which of the following statements about the molecular architecture of DNA is true?
a. The two strands run in opposite directions.
b. The molecule’s twist is right-handed.
c. The molecule is a double-stranded helix.
d. It has a uniform diameter.
33. What accounts for the uniform diameter of the DNA molecule?
b. A purine always bonds with a pyrimidine.
34. The strands that make up DNA are antiparallel. This means that
c. the 5’ to 3’ direction of one strand is counter to the 5’ to 3’ direction of the other strand.
35. The antiparallel relationship of the two strands of DNA refers to the
c. alignment of the strands, such that one strand starts with a 3’ carbon and the other starts with a 5’ carbon.
36. The force of _______ holds DNA together in a double helix.
e. hydrogen bonds
37. Which one of the following is not found in DNA?
38. Although DNA is made up of only four different bases, it can encode the information necessary to specify the workings of an entire organism because DNA
a. molecules are extremely long.
39. The structure of DNA explains which three major properties of genes?
e. They contain information, replicate exactly, and can change to produce a mutation.
40. Mutations are
b. heritable changes in the sequence of DNA bases.
41. The first scientist(s) to suggest a mode of replication for DNA was (were)
d. Watson and Crick.
42. A deoxyribose nucleoside is a
a. deoxyribose plus a nitrogenous base.
43. Kornberg showed that new DNA molecules can be synthesized in a test tube containing deoxyribose
c. nucleoside triphosphates.
44. At the end of DNA replication, two DNA molecules are produced, each one consisting of a parental DNA strand and a new DNA strand. This process is known as
a. semiconservative replication.
45. In the Meselson–Stahl experiment, the conservative model of DNA replication was ruled out by which of the following observations?
a. No completely “heavy” DNA was observed after the first round of replication.
46. During DNA replication
b. the template strands must separate so that both can be copied.
47. If Meselson and Stahl had observed one intermediate, slightly smeared band after growing bacteria for one generation, and then after two generations again had found one slightly smeared band, they would most likely have concluded that DNA replicates
48. In DNA replication, each newly made strand is
b. complementary in sequence to the strand from which it was copied.
49. Semiconservative replication of DNA involves
a. each of the original strands acting as a template for a new strand.
50. In a growing DNA strand, each monomer is added to which carbon of the deoxyribose?
51. During replication, the new DNA strand is synthesized
b. in the 5’ to 3’ direction.
52. DNA replication in eukaryotes differs from replication in bacteria because
c. there are many replication forks in each eukaryotic chromosome and only one in bacterial DNA.
53. In eukaryotic cells, each chromosome has
c. many origins of replication.
54. The energy necessary for making a DNA molecule comes directly from the
c. release of phosphates.
55. Pyrophosphate is a
b. by-product of DNA synthesis.
56. DNA polymerase lengthens a polynucleotide strand by
d. covalently linking new nucleotides to a previously existing strand.
57. Why is RNA incorporated into the DNA molecule during DNA replication?
d. DNA polymerases can only add on to an existing strand.
58. The molecules that function to replicate DNA in the cell are
b. DNA polymerases.
59. Which of the following is the correct order of events for synthesis of the lagging strand?
a. Primase adds RNA primer, DNA polymerase III creates a stretch, DNA polymerase I removes the primer, and ligase seals the gaps.
60. Fragments like those now called Okazaki fragments were expected even before they were discovered because
b. the replication fork moves forward along a double-stranded DNA molecule.
61. In eukaryotes, Okazaki fragments are about _______ base pairs long.
62. The enzyme DNA ligase is required continuously during DNA replication because
b. fragments of the lagging strand must be joined together.
63. In bacteria, the enzyme that removes the RNA primers is called
e. DNA polymerase I
64. The enzyme that restores the phosphodiester linkage between adjacent fragments in the lagging strand during DNA replication is
a. DNA ligase.
65. The enzyme that unwinds the DNA prior to replication is called
66. Fourteen human DNA polymerases have been identified. Which of the following statements about them is true?
e. Only one of the fourteen is involved in DNA replication; the others are involved in primer removal and DNA repair.
67. Why don’t cells last the entire lifetime of an organism?
a. The removal of the RNA primer following DNA replication leads to a shortening of the chromosome and eventual cell death.
68. In the cells of prokaryotes, methylated guanine contributes to
e. correcting of mismatched pairs of bases.
69. The first repair of mistakes during DNA replication is made by
b. DNA polymerase.
70. The error rate of changing an incorrect base with another incorrect base during proofreading is one in _______ bases.
71. The fidelity of DNA replication is astounding. During DNA synthesis, the error rate is on the order of one wrong nucleotide per
72. In PCR, _______ creates single-stranded DNA template molecules.
73. Ideally, PCR _______ increases the amount of DNA during additional cycles.
74. The maximum length of a DNA sequence that can be determined using current technology is approximately _______ base pairs.
1. The material that changed R strain pneumococcus into the virulent S strain was originally referred to as the _______.
2. The nitrogenous bases classified as purines are _______ and _______.
3. Watson and Crick used three-dimensional representations of the possible molecular structure of DNA to determine its actual structure. This process is called _______.
4. The nitrogenous bases classified as pyrimidines are _______ and _______.
5. The X-ray crystallographs of the English chemist _______ were essential for the discovery of the structure of the DNA molecule.
6. The basic units of DNA and RNA molecules are the _______.
7. The purines take up (more/less) _______ space in the center of a DNA molecule than the pyrimidines do.
8. Since the DNA molecule is continuous, nucleotide pair after nucleotide pair, their information must lie in the _______ sequence of the nitrogenous bases.
9. Arthur Kornberg showed that DNA could replicate in the test tube if it contained intact DNA for a template, a mixture of the four precursors (the four nucleoside triphosphates), and _______.
10. The experiments of Meselson and Stahl established the _______ of DNA.
11. Meselson experimental system for studying the mode of replication of DNA, researchers analyze information from a life-form from Mars. After the first round of replication, they see two distinct bands in the This finding is consistent with the principle of _______ replication.
12. The region of DNA where replication begins is called the _______.
13. In bacteria, the enzyme that replicates the lagging strand is _______.
14. In prokaryotes, the enzyme that replicates the leading strand is _______.
15. The fragments of RNA and DNA found on the lagging strand of DNA before RNA removal and ligation are called _______.
16. The repetitive sequences at the end of many chromosomes are called _______.
17. An enzyme that is found in 90 percent of human cancers and may be responsible for the continuous division of cancer cells is _______.
18. An enzyme that catalyzes the addition of any lost telomere sequences is _______.
19. The _______ function of DNA polymerase reduces the number of mistakes by the square of the frequency of the error rate.
20. An automated process that makes multiple copies of short regions of DNA in a test tube is called _______.
21. In a sequencing reaction, the shortest sequences are those that end closer to the _______ end than to the _______ end of the synthesized molecule.
22. The technique that sorts DNA fragments by length and detects differences in DNA fragment length is called _______.
Sign up for free and study better.
Get started today!