Biology - Chapter 16
12. The information in DNA is contained in _____. a) the variation in the structure of nucleotides that make up the DNA molecule b) the sequence of nucleotides along the length of the two strands of the DNA molecule c) the sequence of amino acids that makes up the DNA molecule d) the types of sugars used in making the DNA molecule e) All of the listed responses are correct.
B
25. What enzyme joins Okazaki fragments? a) Helicase b) DNA ligase c) DNA polymerase d) Topoisomerase e) Primase
B
30. Once the DNA at the replication fork is unwound by helicases, what prevents the two strands from coming back together to re-form a double helix? a) DNA polymerase follows the helicase so closely that there is no chance for the strands to come back together. b) Single-strand binding proteins bind the unwound DNA and prevent the double helix from re-forming. c) The helicase modifies the DNA in such a way as to eliminate the affinity between the two strands. d) The helicase pushes the two strands so far apart that they have no chance of finding each other. e) One of the strands is rapidly degraded, preventing the double helix from re-forming.
B
32. The overall error rate in the completed DNA molecule is approximately _____. a) 1 error per 1,000 nucleotides b) 1 error per 10,000,000,000 nucleotides c) 1 error per 100 nucleotides d) 1 error per 1,000,000,000 nucleotides e) 1 error per 1,000,000 nucleotides
B
14. Which of the following attributes of DNA is most crucial to its accurate duplication? a) its specific base pairing and hydrogen bonding b) its specific sequence of bases c) its helical nature and hydrogen bonding d) its deoxyribose sugar and phosphate groups
A
16. The experiments of Meselson and Stahl showed that DNA _____. a) replicates in a semiconservative fashion b) contains complementary base pairing c) is composed of nucleotides d) codes for the sequence of amino acids in proteins e) is the genetic material
A
17. The DNA structures of prokaryotes and eukaryotes are different in several ways, but one way in which they are the same is that _____. a) both have a sugar-phosphate backbone b) most of the DNA is in the form of plasmids c) the DNA is packaged into several linear chromosomes d) both have a single circular chromosome e) histones are present in the nucleosomes
A
19. At each end of a DNA replication bubble is _____. a) a replication fork b) a ribosome c) an origin of replication d) a gene e) a telomere
A
2. Avery and his colleagues' 1944 experiment showed that DNA _____. a) was the substance that transformed the bacteria in Griffith's experiment b) contains adenine, guanine, thymine, and cytosine c) uses three bases to code for one amino acid d) consists of sugars, phosphate groups, and bases e) has two strands held together with hydrogen bonds
A
24. DNA polymerase adds nucleotides to the _____ of the leading strands, and to the _____ of the lagging strands (Okazaki fragments). a) 3′ end ... 3′ end b) 5′ end ... 5′ end c) 3′ end ... 5′ end d) sugar group ... phosphate group e) 5′ end ... 3′ end
A
27. Which of the following components is required for DNA replication? a) RNA primer b) transfer RNA c) proteases d) sucrases e) ribosomes
A
33. The incorporation of an incorrect base into the DNA during replication _____. a) will trigger the cell to destroy the new strand, and replication will begin again b) can be repaired by the mismatch repair system c) cannot be repaired, and a new mutation will invariably result d) will almost certainly lead to the death of the cell e) is virtually impossible, as the accuracy of DNA polymerase is such that errors almost never occur
B
36. Telomerase _____. a) slows the rate of cancer cell growth b) is an enzyme that lengthens telomeres c) prevents the loss of centromeric DNA d) splits telomeres e) speeds cell aging
B
39. The "beads on a string" seen in interphase chromatin are _____. a) looped domains b) nucleosomes c) histone tails d) heterochromatin e) nucleoids
B
9. In DNA, the two purines are _____, and the two pyrimidines are _____. a) adenine and cytosine ... guanine and thymine b) adenine and guanine ... cytosine and thymine c) cytosine and guanine ... adenine and thymine d) adenine and thymine ... cytosine and guanine e) cytosine and thymine ... adenine and guanine
B
13. Who is credited with explaining the structure of the DNA double helix? a) Avery, McCarty, and MacLeod b) Jacob and Monod c) Watson and Crick d) Griffith e) Hershey and Chase
C
29. The unwinding of DNA at the replication fork causes twisting and strain in the DNA ahead of the fork, which is relieved by an enzyme called _____. a) Primase b) Ribosomes c) Topoisomerase d) Relievase e) Ligase
C
3. A scientist assembles a bacteriophage with the protein coat of phage T2 and the DNA of phage T4. If this composite phage were allowed to infect a bacterium, the phages produced in the host cell would have _____. a) the protein of T2 and the DNA of T4 b) the protein of T4 and the DNA of T2 c) the protein and DNA of T4 d) a mixture of the DNA and proteins of both phages e) the protein and DNA of T2
C
1. During Griffith's experiments with Streptococcus pneumoniae in mice, material from _____ bacteria transformed _____ bacteria. a) living nonvirulent ... heat-killed virulent b) living nonvirulent ... living virulent c) living virulent ... heat-killed nonvirulent d) heat-killed virulent ... living nonvirulent e) heat-killed nonvirulent ... living virulent
D
10. Which of the following is correct? a) Adenine forms two covalent bonds with thymine; guanine forms three covalent bonds with cytosine. b) Adenine forms three covalent bonds with thymine; guanine forms two covalent bonds with cytosine. c) Adenine forms two hydrogen bonds with guanine; thymine forms three hydrogen bonds with cytosine. d) Adenine forms two hydrogen bonds with thymine; guanine forms three hydrogen bonds with cytosine. e) Adenine forms three hydrogen bonds with thymine; guanine forms two hydrogen bonds with cytosine.
D
20. The role of DNA polymerases in DNA replication is to _____. a) separate the two strands of DNA b) link together short strands of DNA c) synthesize an RNA primer to initiate DNA strand synthesis d) attach free nucleotides to the new DNA strand e) All of the listed responses are correct.
D
21. The rate of elongation in prokaryotes is _____ the rate in eukaryotes. a) sometimes faster and sometimes slower than b) The rates are not comparable, because elongation only occurs in prokaryotes. c) about the same speed as d) much faster than e) much slower than
D
22. The two strands of a DNA double helix are antiparallel. This means that _____. a) the two strands are mirror images b) only one of the two strands can be used as a template for replication, because DNA polymerase only works in one direction c) one strand is actually composed of RNA d) one strand runs in the 5' to 3' direction, and the other runs in the 3' to 5' direction e) they both run in the 3' to 5' direction
D
26. After the formation of a replication bubble, which of the following is the correct sequence of enzymes used for the synthesis of the lagging DNA strand? a) helicases, DNA polymerases, primase, ligase b) primase, helicases, DNA polymerases, ligase c) ligase, primase, DNA polymerases, helicases d) helicases, primase, DNA polymerases, ligase e) helicases, primase, ligase, DNA polymerases
D
34. Which set of enzymes is involved in nucleotide excision repair? a) nuclease, DNA polymerase, primase b) DNA polymerase, helicase, primase c) hydrolase, nuclease, and ligase d) nuclease, DNA polymerase, and ligase e) ligase, nuclease, and primase
D
35. Telomeres _____. a) get longer with continued cell division b) remain the same regardless of the frequency of cell division c) are found in both prokaryotic and eukaryotic cells d) get shorter with continued cell division e) are shorter for younger individuals
D
37. What is the major difference between bacterial chromosomes and eukaryotic chromosomes? a) The DNA of bacterial chromosomes has a slightly different structure. b) Eukaryotes have a single circular chromosome whereas bacteria have several linear chromosomes. c) There is no difference between bacterial and eukaryotic chromosomes. d) Bacteria have a single circular chromosome whereas eukaryotes have several linear chromosomes. e) Bacterial chromosomes have much more protein associated with the DNA than eukaryotes.
D
38. Put the following DNA-containing entities in order according to the amount of DNA found in their genomes. a) bacteria, eukaryote, virus b) eukaryote, virus, bacteria c) bacteria, virus, eukaryote d) virus, bacteria, eukaryote e) They all have about the same amount of DNA.
D
4. In an important experiment, a radioactively labeled bacteriophage was allowed to infect bacteria. In a first trial, the phage contained radioactive DNA, and radioactivity was detected inside the bacteria. Next, phage containing radioactive protein was used, and the radioactivity was not detected inside the bacteria. These experiments led to the conclusion that _____. a) bacteriophages can infect bacteria b) the genetic material of the phage is protein c) genes are on chromosomes d) the genetic material of the phage is DNA e) DNA is made of nucleotides
D
5. Up until Hershey and Chase showed that DNA was the genetic molecule, what molecule was considered the best candidate for carrying genetic information and why? a) amino acids because of all the ways they can join together b) carbohydrates because they are found in abundance in all organisms c) sterols because of the different variations on their ring structure d) proteins because they were thought to be the only molecule with both the variety and specificity of function to account for the array of heritable traits observed e) nucleoside triphosphates because of the ability to add and remove phosphate groups
D
7. Chargaff found that for DNA _____. a) A + T = 50% of the total bases b) the ratio of A to C is close to 1:1 and the ratio of G to T is close to 1:1 c) the ratio of A to G is close to 1:1 and the ratio of T to C is close to 1:1 d) the ratio of A to T is close to 1:1 and the ratio of G to C is close to 1:1 e) A + T = G + C
D
8. What technique was most helpful to Watson and Crick in developing their model for the structure of DNA? a) cloned DNA b) electrophoresis c) radioactive labeling d) X-ray crystallography e) transgenic animals
D
11. The two sugar-phosphate strands that form the rungs of a DNA double helix are joined to each other through _____. a) covalent bonds between nitrogen atoms in adenine and in thymine b) covalent bonds between carbon atoms in deoxyribose molecules c) ionic bonds between guanine and cytosine d) 5' deoxyribose and phosphate bonds e) hydrogen bonds between nucleotide bases
E
15. During the replication of DNA, _____. a) the reaction is catalyzed by RNA polymerase b) errors never occur c) the cell undergoes mitosis d) only one strand of the molecule acts as a template e) both strands of a molecule act as templates
E
18. Which of the following statements about replication origins is correct? a) In bacteria, the DNA sequence at the origin is recognized by specific proteins that then bind to the origin. b) In both prokaryotes and eukaryotes, replication proceeds in both directions from each origin. c) Bacterial chromosomes have a single origin, but eukaryotic chromosomes have many origins. d) The two strands of DNA at the origin are separated, allowing the formation of a replication bubble. e) All of the listed responses are correct.
E
23. One strand of a DNA molecule has the base sequence 5′-ATAGGT-3′. The complementary base sequence on the other strand of DNA will be 3′-_____-5′. a) UAUCCA b) TGGATA c) ATAGGT d) TGGAUA e) TATCCA
E
28. The removal of the RNA primer and addition of DNA nucleotides to the 3' end of Okazaki fragments in its place is carried out by _____. a) Nuclease b) Ligase c) Primase d) DNA polymerase III e) DNA polymerase I
E
31. Which description of DNA replication is correct? a) Ligase assembles single-stranded codons, then polymerase knits these codons together into a DNA strand. b) The two strands of DNA separate, and restriction enzymes cut up one strand. Then, the DNA polymerase synthesizes two new strands out of the old ones. c) Ligase separates the two strands of the DNA double helix. Then, DNA polymerase synthesizes the leading strand and primase synthesizes the lagging strand. d) The two strands separate, and each one receives a complementary strand of RNA. Then this RNA serves as a template for the assembly of many new strands of DNA. e) Helicases separate the two strands of the double helix, and DNA polymerases then construct two new strands using each of the original strands as templates.
E
6. Monomers for the synthesis of DNA are called _____. a) Disaccharides b) amino acids c) fatty acids d) monosaccharides e) nucleotides
E
