Biology Chapter 16

C

Which of the following techniques was most helpful to Watson and Crick in developing their model for the structure of DNA? (eText Concept 16.1) A. cloned DNA B. transgenic animals C. X-ray crystallography D. electrophoresis E. radioactive labeling

D

The role of DNA polymerases in DNA replication is to __________. (eText Concept 16.2) A. link together short strands of DNA B. synthesize an RNA primer to initiate DNA strand synthesis C. separate the two strands of DNA D. attach free nucleotides to the new DNA strand E. All of the listed responses are correct.

C

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 __________. (eText Concept 16.1) A. the protein of T4 and the DNA of T2 B. the protein of T2 and the DNA of T4 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

B

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? (eText Concept 16.2) A. helicase, primase, ligase, DNA polymerase B. helicase, primase, DNA polymerase, ligase C. helicase, DNA polymerase, primase, ligase D. primase, helicase, DNA polymerase, ligase E. ligase, primase, DNA polymerase, helicase

E

As a result of proofreading by DNA polymerases, the overall error rate in the completed DNA molecule is approximately __________. (eText Concept 16.2) A. 1 error per 100 nucleotides B. 1 error per 1,000 nucleotides C. 1 error per 1,000,000 nucleotides D. 1 error per 1,000,000,000 nucleotides E. 1 error per 10,000,000,000 nucleotides

E

At each end of a DNA replication bubble is __________. (eText Concept 16.2) A. a telomere B. a ribosome C. an origin of replication D. a gene E. a replication fork

A

Avery and his colleagues' 1944 experiment showed that DNA __________. (eText Concept 16.1) A. was the substance that transformed the bacteria in Griffith's experiment B. has two strands held together with hydrogen bonds C. contains adenine, guanine, thymine, and cytosine D. uses three bases to code for one amino acid E. consists of sugars, phosphate groups, and bases

E

Chargaff found that for DNA __________. (eText Concept 16.1) A. A + T = G + C B. the ratio of A to G is close to 1:1 and the ratio of T to C is close to 1:1 C. A + T = 50% of the total bases D. the ratio of A to C is close to 1:1 and the ratio of G to T is close to 1:1 E. the ratio of A to T is close to 1:1 and the ratio of G to C is close to 1:1

C

DNA polymerase adds nucleotides to the __________ of the leading strands, and to the __________ of the lagging strands (Okazaki fragments). (eText Concept 16.2) A. 5′ end ... 5′ end B. 3′ end ... 5′ end C. 3′ end ... 3′ end D. sugar group ... phosphate group E. 5′ end ... 3′ end

D

During Griffith's experiments with Streptococcus pneumoniae in mice, material from __________ bacteria transformed __________ bacteria. (eText Concept 16.1) A. living nonpathogenic ... heat-killed pathogenic B. heat-killed pathogenic ... living nonpathogenic C. living pathogenic ... heat-killed nonpathogenic D. heat-killed nonpathogenic ... living pathogenic E. living nonpathogenic ... living pathogenic

E

During the replication of DNA, __________. (eText Concept 16.2) A. only one strand of the molecule acts as a template B. the cell undergoes mitosis C. the reaction is catalyzed by RNA polymerase D. errors never occur E. both strands of a molecule act as templates

D

In DNA, the two purines are __________, and the two pyrimidines are __________. (eText Concept 16.1) A. cytosine and guanine ... adenine and thymine B. cytosine and thymine ... adenine and guanine C. adenine and thymine ... cytosine and guanine D. adenine and guanine ... cytosine and thymine E. adenine and cytosine ... guanine and thymine

C

In a comparison between asexually reproducing bacteria and sexually reproducing multicellular eukaryotes, uncorrected errors in replication are more likely to be transmitted to subsequent generations in bacteria than in multicellular eukaryotes. Which of the following provides the best evidence-based explanation for this difference?(eText Concept 16.2) A. Although the genome for each is represented as pairs of homologous chromosomes, errors in bacteria affect both homologs, but only one is affected in eukaryotes. B. Unlike multicellular eukaryotes, bacteria lack DNA repair enzymes, so there are just more uncorrected errors at play. C. Because they are asexual and single-celled, all uncorrected errors of replication in bacteria are transmitted to subsequent generations. Multicellular eukaryotes typically reproduce sexually, so uncorrected errors are transmitted only if they occur in germ cells that meiotically divide to produce gametes. D. Only errors that lead to faster growing strains are left uncorrected in bacteria, whereas all errors are detected and repaired in multicellular eukaryotes. E. The third and fourth listed responses can explain this phenomenon.

A

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 __________. (eText Concept 16.1) A. the genetic material of the phage is DNA B. the genetic material of the phage is protein C. genes are on chromosomes D. DNA is made of nucleotides E. bacteriophages can infect bacteria

B

In prokaryotes, the rate of elongation during DNA replication is __________ the rate in eukaryotes. (eText Concept 16.2) A. about the same as B. much faster than C. much slower than D. sometimes faster and sometimes slower than E. The rates are not comparable, because elongation only occurs in prokaryotes.

E

In the "beads on a string" structure of unfolded chromatin, the "beads" are __________. (eText Concept 16.3) A. looped domains B. heterochromatin C. nucleoids D. genes E. nucleosomes

A

Monomers for the synthesis of DNA are called __________. (eText Concept 16.1) A. nucleotides B. fatty acids C. amino acids D. disaccharides E. monosaccharides

E

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? (eText Concept 16.2) A. The helicase modifies the DNA in such a way as to eliminate the affinity between the two strands. B. The helicase pushes the two strands so far apart that they have no chance of finding each other. C. One of the strands is rapidly degraded, preventing the double helix from re-forming. D. DNA polymerase follows the helicase so closely that there is no chance for the strands to come back together. E. Single-strand binding proteins bind the unwound DNA and prevent the double helix from re-forming.

A

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′. (eText Concept 16.2) A. TATCCA B. UAUCCA C. TGGATA D. ATAGGT E. TGGAUA

A

The information in DNA is contained in __________. (eText Concept 16.1) A. the sequence of nucleotides along the length of the two strands of the DNA molecule B. the types of sugars used in making the DNA molecule C. the sequence of amino acids that makes up the DNA molecule D. the variation in the structure of nucleotides that make up the DNA molecule E. All of the listed responses are correct.

E

Telomerase __________. (eText Concept 16.2) A. speeds cell aging B. slows the rate of cancer cell growth C. prevents the loss of centromeric DNA D. splits telomeres E. is an enzyme that lengthens telomeres

C

Telomeres __________. (eText Concept 16.2) A. get longer with each round of DNA replication B. are found in both prokaryotic and eukaryotic cells C. get shorter with each round of DNA replication D. are shorter for younger individuals E. remain the same regardless of the frequency of DNA replication

E

The experiments of Meselson and Stahl showed that DNA __________. (eText Concept 16.2) A. is composed of nucleotides B. codes for the amino acid sequences of proteins C. contains complementary base pairing D. is the genetic material E. replicates in a semiconservative fashion

E

The incorporation of an incorrect base into the DNA during replication __________. (eText Concept 16.2) A. will trigger the cell to destroy the new strand, and replication will begin again B. will almost certainly lead to the death of the cell C. cannot be repaired, and a new mutation will invariably result D. is virtually impossible, as the accuracy of DNA polymerase is such that errors almost never occur E. can be repaired by the mismatch repair system

C

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 __________. (eText Concept 16.2) A. ligase B. DNA polymerase III C. DNA polymerase I D. nuclease E. primase

D

The two antiparallel strands of nucleotides that form the DNA double helix are held together by __________. (eText Concept 16.1) A. covalent bonds between carbon atoms in deoxyribose molecules B. 5' deoxyribose and phosphate bonds C. covalent bonds between nitrogen atoms in adenine and in thymine D. hydrogen bonds between nucleotide bases E. ionic bonds between guanine and cytosine

C

The two strands of a DNA double helix are antiparallel. This means that __________. (eText Concept 16.2) A. one strand is actually composed of RNA 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 runs in the 5' to 3' direction, and the other runs in the 3' to 5' direction D. the two strands are mirror images E. they both run in the 3' to 5' direction

D

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 __________. (eText Concept 16.2) A. helicase B. ligase C. primase D. topoisomerase E. relievase

D

Unlike prokaryotic DNA replication, replication of eukaryotic chromosomes __________. (eText Concept 16.2) A. is semiconservative B. has a single origin C. is error-free D. cannot be completed by DNA polymerase E. involves two leading strands and no lagging strands

B

Until Hershey and Chase showed that DNA was the genetic molecule of the phages they studied, what class of molecules was considered the best candidate for carrying genetic information and why? (eText Concept 16.1) A. sterols because of the different variations on their ring structure B. 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 C. amino acids because of all the ways they can join together D. carbohydrates because they are found in abundance in all organisms E. nucleoside triphosphates because of the ability to add and remove phosphate groups

D

What enzyme joins Okazaki fragments? (eText Concept 16.2) A. primase B. topoisomerase C. DNA polymerase D. DNA ligase E. helicase

E

What is the major difference between bacterial chromosomes and eukaryotic chromosomes? (eText Concept 16.3) A. The DNA molecules of bacterial chromosomes have a slightly different structure than those of eukaryotic chromosomes. B. Eukaryotes have a single circular chromosome whereas bacteria have several linear chromosomes. C. Bacterial chromosomes have much more protein associated with the DNA than eukaryotes. D. There is no difference between bacterial and eukaryotic chromosomes. E. Bacteria usually have a single circular chromosome whereas eukaryotes have several linear chromosomes.

B

Which of the following attributes of DNA is most crucial to its accurate duplication? (eText Concept 16.2) A. its deoxyribose sugar and phosphate groups B. its specific base pairing through hydrogen bonds C. its helical nature and hydrogen bonding D. its specific sequence of bases E. its phosphodiester linkages and complementary strands

D

Which of the following components is required for DNA replication? (eText Concept 16.2) A. messenger RNA B. proteases C. sucrases D. RNA primer E. ribosomes

E

Which of the following considerations was/were important in the choice of viruses and bacteria for early experiments on DNA? (eText Concept 16.3) A. They have short generation times. B. They can interact with each other. C. Their chromosomes have a simpler structure. D. They typically have relatively small genomes. E. All of the listed responses are correct.

E

Which of the following statements about replication origins is/are correct? (eText Concept 16.2) A. Bacterial chromosomes have a single origin of replication, but eukaryotic chromosomes have many origins. B. The DNA sequence at the origin of replication is recognized by specific proteins that bind to the origin. C. Replication proceeds in both directions from each origin. D. The two strands of DNA at the origin of replication are separated, creating a replication bubble. E. All of the listed responses are correct

E

Which of the following statements is/are correct with regard to individuals with the disorder xeroderma pigmentosum? (eText Concept 16.2) A. These individuals have high rates of skin cancer. B. Cells in these individuals have difficulty repairing thymine dimers. C. These individuals are extremely sensitive to sunlight. D. These individuals usually have inherited defects in the nucleotide excision repair system. E. All of the listed responses are correct.

B

Which one of the following statements is correct? (eText Concept 16.1) A. Adenine forms two hydrogen bonds with guanine; thymine forms three hydrogen bonds with cytosine. B. Adenine forms three hydrogen bonds with thymine; guanine forms two hydrogen bonds with cytosine. C. Adenine forms two covalent bonds with thymine; guanine forms three covalent bonds with cytosine. D. Adenine forms three covalent bonds with thymine; guanine forms two covalent bonds with cytosine. E. Adenine forms two hydrogen bonds with thymine; guanine forms three hydrogen bonds with cytosine

C

Which one of the following statements regarding DNA replication is correct? (eText Concept 16.2) A. The two strands of DNA separate, and nuclease enzymes digest one strand. Then, DNA polymerase synthesizes two new strands out of the old ones. B. Ligase assembles nucleotides into Okazaki fragments. Then polymerase joins these fragments together into a DNA strand. C. 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. 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. Ligase separates the two strands of the DNA double helix. Then, DNA polymerase synthesizes the leading strand and primase synthesizes the lagging strand.

C

Which set of enzymes is involved in nucleotide excision repair? (eText Concept 16.2) A. hydrolase, nuclease, and ligase B. nuclease, DNA polymerase, primase C. nuclease, DNA polymerase, and ligase D. DNA polymerase, helicase, primase E. ligase, nuclease, and primase

E

Who is credited with explaining the structure of the DNA double helix? (eText Concept 16.1) A. Hershey and Chase B. Griffith C. Rosalind Franklin D. Avery, McCarty, and MacLeod E. Watson and Crick