Chapter 13

are the short sections of DNA that are synthesized on the lagging strand of the replicating DNA.

. Okazaki fragments

Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human's genes? Subject the DNA to restriction enzymes. Use a nucleic acid probe. Subject the specimen to amniocentesis. Subject the DNA to electrophoresis .Use the polymerase chain reaction.

.Use the polymerase chain

In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the phosphate group is attached to the sugar's _____ carbon.

1' ... 5'

If one strand is 5'-GCAC-3', the complementary strand must be

3'-CGTG-5

For this question, consider only DNA nucleotides.

4

At a specific area of a chromosome, the following sequence of nucleotides is present where the chain opens to form a replication fork:3' C C T A G G C T G C A A T C C 5'An RNA primer is formed starting at the underlined T (T) of the template. Which of the following represents the primer sequence?

5' A C G U U A G G 3'

An Okazaki fragment has which of the following arrangements? DNA polymerase I, DNA polymerase III 3' RNA nucleotides, DNA nucleotides 5'primase, polymerase, ligase 5' RNA nucleotides, DNA nucleotides 3' 5' DNA to 3'

5' RNA nucleotides, DNA nucleotides 3'

Nucleic acids are assembled in the _____ direction.

5' to 3'

\Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine? 8% 16% 31% 42%

8%

In an analysis of the nucleotide composition of DNA, which of the following will be found? A = C G + C = T + A A + C = G + T A = G and C = T

A + C = G + T

In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules? A = G A = C A + G = C + T A + T = G + C

A + G = C + T

Which enzyme(s) will produce a DNA fragment that contains the entire vgp gene (shown in red) and has "sticky ends"? Select all that apply. EcoRI BamHI HindIII HaeIII

BamHI HindIII

Which one restriction enzyme satisfies all three of the requirements listed above?

BamHI only

Which enzyme would cut the plasmid without disrupting the function of the ampR gene?

BamHI, EcoRI, and HaeIII

Which enzyme would produce sticky ends when cutting both the human DNA and the plasmid?

BamHI, EcoRI, and HindIII

Which enzyme would cut the human DNA shown in Part A on both sides of the vip gene, but not inside the gene?

BamHI, HaeIII, and HindIII

Part complete A nitrogenous base is indicated by the letter _____.

C

Which of these is(are) pyrimidines?

C, D, and E

Part complete Which of these is responsible for catalyzing the formation of an RNA primer?

D

What are chromosomes made of? DNA and proteins DNA, heterochromatin, and histone proteins DNA and euchromatin DNA, RNA, and proteins DNA

DNA and proteins

Which of these is a difference between a DNA and an RNA molecule? DNA is a polymer composed of nucleotides, whereas RNA is a polymer composed of nucleic acids. DNA contains nitrogenous bases, whereas RNA contains phosphate groups. DNA contains five-carbon sugars, whereas RNA contains six-carbon sugars. DNA contains uracil, whereas RNA contains thymine. DNA is usually double-stranded, whereas RNA is usually single-stranded.

DNA is usually double-stranded, whereas RNA is usually single-stranded.

A student isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. After adding some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has the student probably LEFT OUT of the mixture? DNA polymerase primase DNA ligase Okazaki fragments

DNA ligase

What enzyme forms covalent bonds between restriction fragments? DNA primase DNA helicase single-strand binding protein DNA polymerase DNA ligase

DNA ligase

What catalyzes DNA synthesis? Primer DNA polymerase dNTPs Replication fork

DNA polymerase

During DNA replication, which of the following enzymes removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments? helicase DNA polymerase III ligase DNA polymerase I

DNA polymerase I

Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments? DNA polymerase can assemble DNA only in the 3' to 5' direction it is more efficient than assembling complete new strands DNA polymerase can assemble DNA only in the 5' to 3' direction only short DNA sequences can extend off the RNA primers the replication forks block the formation of longer strands

DNA polymerase can assemble DNA only in the 5' to 3' direction

Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments? it is more efficient than assembling complete new strands DNA polymerase can assemble DNA only in the 5' to 3' direction only short DNA sequences can extend off the RNA primers DNA polymerase can assemble DNA only in the 3' to 5' direction the replication forks block the formation of longer strands

DNA polymerase can assemble DNA only in the 5' to 3' direction

Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments? the replication forks block the formation of longer strands only short DNA sequences can extend off the RNA primers it is more efficient than assembling complete new strands DNA polymerase can assemble DNA only in the 5' to 3' direction DNA polymerase can assemble DNA only in the 3' to 5' direction

DNA polymerase can assemble DNA only in the 5' to 3' direction

What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized? The origins of replication occur only at the 5' end. Helicases and single-strand binding proteins work at the 5' end. DNA polymerase can join new nucleotides only to the 3' end of a preexisting strand. DNA ligase works only in the 3' → 5' direction

DNA polymerase can join new nucleotides only to the 3' end of a preexisting strand.

A new DNA strand elongates only in the 5' to 3' direction because Okazaki fragments prevent elongation in the 3' to 5' direction. DNA polymerase begins adding nucleotides at the 5' end of the template. DNA polymerase can only add nucleotides to the free 3' end. replication must progress toward the replication fork. Submit

DNA polymerase can only add nucleotides to the free 3' end.

The lagging strand is characterized by a series of short segments of DNA (Okazaki fragments) that will be joined together to form a finished lagging strand. The experiments that led to the discovery of Okazaki fragments gave evidence for which of the following ideas? Bacterial replication is fundamentally different from eukaryotic replication. DNA is a polymer consisting of four monomers: adenine, thymine, guanine, and cytosine. DNA polymerase is a directional enzyme that synthesizes leading and lagging strands during replication. DNA is the genetic material.

DNA polymerase is a directional enzyme that synthesizes leading and lagging strands during replication

. The enzyme that can replicate DNA is called

DNA polymerase.

Select the most accurate statement describing DNA replication complexes. DNA replication complexes are grouped into factories, which are anchored to the nuclear matrix. DNA and the DNA replication complexes fit together like a lock and key. DNA replication complexes move along a DNA railway track.

DNA replication complexes are grouped into factories, which are anchored to the nuclear matrix.

Meselson and Stahl cultured E. coli for several generations in a medium with a heavy isotope of nitrogen, 15N. They transferred the bacteria to a medium with a light isotope of nitrogen, 14 N. After two rounds of DNA replication, half the DNA molecules were light (both strands had 14N) and half were hybrids (15N-14N). What did the researchers conclude from these results? DNA replication is semiconservative. Opposite DNA strands are complementary to each other. The nitrogenous bases in DNA molecules incorporate both 15N and 14N.

DNA replication is semiconservative.

During DNA replication, the leading strand is synthesized continuously, whereas the lagging strand is synthesized as Okazaki fragments. Why is this so? DNA polymerases can bind to only one strand at a time. DNA synthesis can take place only in the 5' to 3' direction. There are thousands of origins of replication on the lagging strand but only one on the leading strand.

DNA synthesis can take place only in the 5' to 3' direction.

DNA replication is said to be semiconservative. What does this mean? One strand of the new double helix is made of DNA, and the other strand is made of RNA. One of the two resulting double helices is made of two old strands, and the other is made of two new strands. Each new double helix consists of one old and one new strand. Half of the old strand is degraded, and half is used as a template for the replication of a new strand. The old double helix is degraded, and half of its nucleotides are used in the construction of two new double helices.

Each new double helix consists of one old and one new strand.

In DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine. Which of the following investigators was (were) responsible for this discovery? Oswald Avery Erwin Chargaff Alfred Hershey and Martha Chase Matthew Meselson and Franklin Stahl Frederick Griffith

Erwin Chargaff

What is the most logical sequence of steps for splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium? Transform bacteria with a recombinant DNA molecule. Cut the plasmid DNA using restriction enzymes. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. Extract plasmid DNA from bacterial cells. Use ligase to seal plasmid DNA to nonplasmid DNA.Extract plasmid DNA from bacterial cells. Cut the plasmid DNA using restriction enzymes. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. Use ligase to seal plasmid DNA to nonplasmid DNA. Transform bacteria with a recombinant DNA molecule.Cut the plasmid DNA using restriction enzymes. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. Use ligase to seal plasmid DNA to nonplasmid DNA. Extract plasmid DNA from bacterial cells. Transform bacteria with a recombinant DNA molecule.Extract plasmid DNA from bacterial cells. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. Use ligase to seal plasmid DNA to nonplasmid DNA. Transform bacteria with a recombinant DNA molecule. Cut the plasmid DNA using restriction enzymes.

Extract plasmid DNA from bacterial cells. Cut the plasmid DNA using restriction enzymes. Hydrogen-bond the plasmid DNA to nonplasmid DNA fragments. Use ligase to seal plasmid DNA to nonplasmid DNA. Transform bacteria with a recombinant DNA molecule.

Who conducted the X-ray diffraction studies that were key to the discovery of the structure of DNA? Franklin McClintock Griffith Chargaff Meselson and Stahl

Franklin

Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme? ACCA TGGT AAAA TTTT AAGG TTCC GGCC CCGG

GGCC CCGG

Part complete Which of the following is a concern expressed by opponents of the use of genetically modified (GM) food crops? Select all that apply. GM food crops might pass their new genes to close relatives in nearby wild areas. GM food crops might pass their new genes to human consumers. The protein products of transgenes in GM food crops might lead to allergic reactions in human consumers.

GM food crops might pass their new genes to close relatives in nearby wild areas. The protein products of transgenes in GM food crops might lead to allergic reactions in human consumers.

Which of the following statements correctly describes chromatin? Euchromatin is not transcribed, whereas heterochromatin is transcribed. Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA. Heterochromatin is highly condensed, whereas euchromatin is less compact. Both heterochromatin and euchromatin are found in the cytoplasm.

Heterochromatin is highly condensed, whereas euchromatin is less compact.

Nucleotides are added to a growing DNA strand as nucleoside triphosphates. What is the significance of this fact? Nucleoside triphosphates are more abundant in the cell than nucleotides. Hydrolysis of the two phosphate groups (P-Pi) and DNA polymerization are a coupled exergonic reaction. Nucleoside triphosphates are more easily transported in the cell than are nucleotides.

Hydrolysis of the two phosphate groups (P-Pi) and DNA polymerization are a coupled exergonic reaction.

f the following is true of DNA during interphase? It is in the form of highly condensed chromosomes and is unavailable for gene expression. It is in the form of highly condensed chromosomes; it is called heterochromatin. It exists as chromatin and is unavailable for gene expression. It exists as chromatin and is less condensed than mitotic chromosomes .It exists as chromatin; it is completely uncoiled and loose.

It exists as chromatin and is less condensed than mitotic chromosomes.

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication? It stabilizes the unwound parental DNA. It catalyzes the lengthening of telomeres .It synthesizes RNA nucleotides to make a primer .It unwinds the parental double helix. It joins Okazaki fragments together.

It joins Okazaki fragments together.

What is the function of helicase in DNA replication? It joins together Okazaki fragments. It checks for errors in the newly synthesized DNA strand. It relieves strain from twisting of the double helix as it is unwound .It untwists the double helix and separates the two DNA strands. It adds nucleotides to the new strand in the 5' to 3' direction.

It untwists the double helix and separates the two DNA strands.

Which part of a deoxynucleoside triphosphate (dNTP) molecule provides the energy for DNA synthesis? Phosphate groups Free 3' hydroxyl (-OH) group Sugar Base

Phosphate groups

Which of the following enzymes creates a primer for DNA polymerase? Primase Ligase Helicase Topoisomerase

Primase

Which of the following statements about DNA synthesis is true? As DNA polymerase moves along the template strand, each new nucleotide provides a 5' hydroxyl group for the next reaction to occur. Primers are short sequences that allow the initiation of DNA synthesis. Nucleotides are added in a random fashion to single-stranded DNA .DNA polymerase adds dNTP monomers in the 3' to 5' direction.

Primers are short sequences that allow the initiation of DNA synthesis

Which of the following statements describes one difference between DNA replication in prokaryotes and DNA replication in eukaryotes? Prokaryotic chromosomes have histones, whereas eukaryotic chromosomes do not. Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many. Prokaryotes have telomeres, and eukaryotes do not. The rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes. Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not.

Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many.

The synthesis of a new strand begins with the synthesis of a(n) _____. RNA primer complementary to a preexisting DNA strand Okazaki fragment poly(A) tail single-strand binding protein short pieces of DNA

RNA primer complementary to a preexisting DNA strand

The synthesis of a new strand begins with the synthesis of a(n) _____. poly(A) tail single-strand binding protein short pieces of DNA Okazaki fragment RNA primer complementary to a preexisting DNA strand

RNA primer complementary to a preexisting DNA strand

In the Hershey and Chase experiment that helped confirm that DNA, not protein, was the hereditary material, what was the key finding? Radioactively labeled phosphorus was found outside of the infected bacteria. Radioactively labeled phosphorus was present inside the infected bacteria. Radioactively labeled sulfur was present inside the infected bacteria. Radioactively labeled carbon was present inside the infected bacteria. Radioactively labeled sulfur was found outside of the infected bacteria.

Radioactively labeled phosphorus was present inside the infected bacteria

A researcher is preparing to insert a human gene of interest into a bacterial plasmid in order to clone the human gene. She has genetically engineered the plasmid to carry a gene amp R , which confers resistance to the antibiotic ampicillin. She will include ampicillin in the plating medium when she grows the recombinant bacteria. Why has she engineered the plasmid to include an antibiotic resistance gene? Choose the best answer. Recombinant bacteria that have taken up the plasmid can be recognized because they are able to survive in the presence of ampicillin. Recombinant bacteria that have taken up the plasmid can be recognized because the antibiotic resistance gene produces a blue color .Recombinant bacteria that have taken up the plasmid are vulnerable to infection and require antibiotic resistance.

Recombinant bacteria that have taken up the plasmid can be recognized because they are able to survive in the presence of ampicillin.

In E. coli replication the enzyme primase is used to attach a 5 to 10 base ribonucleotide strand complementary to the parental DNA strand. The RNA strand serves as a starting point for the DNA polymerase that replicates the DNA. If a mutation occurred in the primase gene, which of the following would you expect? Replication would only occur on the leading strand. Replication would only occur on the lagging strand. Replication would not be affected as the enzyme primase in involved with RNA synthesis. Replication would not occur on either the leading or lagging strand.

Replication would not occur on either the leading or lagging strand.

What is meant by the description "antiparallel" regarding the two strands of nucleic acids that make up DNA? One strand contains only purines and the other contains only pyrimidines. Base pairings create unequal spacing between the two DNA strands. The twisting nature of DNA creates nonparallel strands. The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand

The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.

In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin. Which of the following would you expect as a result of this mutation? No proofreading will occur. The DNA will supercoil. Replication will require a DNA template from another source .The DNA strands at the origin of replication will separate, but replication will not progress.

The DNA strands at the origin of replication will separate, but replication will not progress.

If a cell were unable to produce histone proteins, which of the following would be a likely effect? The cell's DNA couldn't be packed into its nucleus. Expression of other genes would compensate for the lack of histones. Spindle fibers would not form during prophase .DNA polymerase I would not function properly.

The cell's DNA couldn't be packed into its nucleus.

Part complete Why is Suspect 1 considered more likely to have committed the crime than Suspect 2? The crime scene sample contains DNA fragments from both the victim and Suspect 1. The crime scene sample contains DNA fragments from both the victim and Suspect 2. Suspect 1 and the victim have more DNA fragments in common that do the victim and Suspect 2. Suspect 2 and the victim have more DNA fragments in common that do the victim and Suspect 1. Suspect 1 and Suspect 2 have more DNA fragments in common than either have in common with the victim.

The crime scene sample contains DNA fragments from both the victim and Suspect 1.

DNA is a self-replicating molecule. What accounts for this important property of DNA? The nitrogenous bases of the double helix are paired in specific combinations: A with T and G with C. Replication is thermodynamically spontaneous and requires no enzymes. Its two strands are held together by easily broken covalent bonds.

The nitrogenous bases of the double helix are paired in specific combinations: A with T and G with C

Griffith's experiments with S. pneumoniae were significant because they showed that traits could be transferred from one organism to another. What else did he find that was significant? A virus made the bacteria pathogenic. Heat kills bacteria. Protein could not be the genetic material. The transferred traits were heritable. DNA was the genetic material.

The transferred traits were heritable.

Which of the following statements about Okazaki fragments in E. coli is true? They are synthesized in the 3' to 5' direction. They are formed on the lagging strand of DNA. They are sealed together by the action of helicase. They are usually 50 to 500 bases long.

They are formed on the lagging strand of DNA.

Cold case detectives are investigating a homicide that took place 30 years ago. In reexamining the evidence, they find a tiny spot of blood on the victim's clothing that was likely left by the murderer. The DNA in the blood has partially degraded over time. What technique(s) would the blood lab technicians use in their examination of this tiny, degraded blood sample? Select all that apply. They would use a restriction enzyme and DNA ligase to make recombinant DNA from this sample. They would use PCR to amplify the DNA. They would use reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the genes expressed in this DNA.

They would use PCR to amplify the DNA.

Which of the following enzymes is important for relieving the tension in a helix as it unwinds during DNA synthesis? Ligase Single-strand binding proteins Helicase Topoisomerase

Topoisomerase

True or false? Single-stranded DNA molecules are said to be antiparallel when they are lined up next to each other but oriented in opposite directions.

True

Part complete Hershey and Chase used a DNA-based virus for their work. What would the results have been if they had used an RNA virus? With an RNA virus radioactive RNA would have been in the final pellet. With an RNA virus neither sample would have had a radioactive pellet. With an RNA virus radioactive protein would have been in the final pellet. With an RNA virus the protein shell would have been radioactive in both samples.

With an RNA virus radioactive RNA would have been in the final pellet.

Which enzyme was used to produce the molecule in the figure? RNA polymerase a restriction enzyme DNA polymerase ligase

a restriction enzyme

In recombinant DNA experiments, what is used to cut pieces of DNA and what joins the resulting fragments to form recombinant DNA? a transposon ... a plasmid a restriction enzyme ... DNA ligase DNA ligase ... a restriction enzyme a plasmid ... DNA ligase a transposon ... a restriction enzyme

a restriction enzyme ... DNA ligase

Part complete In the accompanying image, a nucleotide is indicated by the letter

b

This is a DNA fingerprint exhibiting samples from a victim, two suspects, and the crime scene. Which of these DNA fragments is common to both the victim and Suspect 1?

b

In order to insert a human gene into a plasmid, both must _____ have identical DNA sequences originate from the same type of cell code for the same gene product be cut by the same restriction enzyme be the same length

be cut by the same restriction enzyme

In this model, the deoxyribose sugar is the blue five-sided structure at the center.

blue

synthesized 5' to 3

both strands

This is a DNA fingerprint exhibiting samples from a victim, two suspects, and the crime scene. Which of these DNA fragments is common to both the victim and Suspect 2?

c

. After replication is complete, the new DNAs, called , are identical to each other.

daughter DNA

The elongation of the leading strand during DNA synthesis __________. occurs in the 3' → 5' direction progresses away from the replication fork produces Okazaki fragments depends on the action of DNA polymerase

depends on the action of DNA polymerase

Which of the following sets of materials is required by both eukaryotes and prokaryotes for DNA replication? topoisomerases, telomerases, polymerases ligase, primers, nucleases double-stranded DNA, four kinds of DNA nucleotides, primers, origins of replication nucleosome loosening, four kinds of DNA nucleotides, four kinds of RNA nucleotides G-C rich regions, polymerases, chromosome nicks

double-stranded DNA, four kinds of DNA nucleotides, primers, origins of replication

After DNA replication is completed, _____. each new DNA double helix consists of one old DNA strand and one new DNA strand one DNA double helix consists of two old strands and one DNA double helix consists of two new strands each new DNA double helix consists of two new strands each of the four DNA strands consists of some old strand parts and some new strand parts there are four double helices

each new DNA double helix consists of one old DNA strand and one new DNA strand

After DNA replication is completed, _____. each of the four DNA strands consists of some old strand parts and some new strand parts each new DNA double helix consists of one old DNA strand and one new DNA strand there are four double helices each new DNA double helix consists of two new strands one DNA double helix consists of two old strands and one DNA double helix consists of two new strands

each new DNA double helix consists of one old DNA strand and one new DNA strand

\After DNA replication is completed, _____. each of the four DNA strands consists of some old strand parts and some new strand parts each new DNA double helix consists of one old DNA strand and one new DNA strand one DNA double helix consists of two old strands and one DNA double helix consists of two new strands each new DNA double helix consists of two new strands

each new DNA double helix consists of one old DNA strand and one new DNA strand

Which of the following functions in the regulation of gene expression? nucleases telomeres euchromatin nucleoids plasmids

euchromatin

During DNA replication, which of the following enzymes separates the DNA strands during replication? helicase DNA polymerase III ligaseDNA polymerase I primase

helicase

The first step in the replication of DNA is catalyzed by _____. ligase single-strand binding protein primase DNA polymerase helicase

helicase

The first step in the replication of DNA is catalyzed by _____. single-strand binding protein ligase primase helicase DNA polymerase

helicase

binds at the replication fork breaks H-bonds between bases

helicase

In a nucleosome, the DNA is wrapped around __________. polymerase molecules a thymine dimer histones ribosomes

histones

Bacteria that contain the plasmid, but not the eukaryotic gene, would grow in all four types of broth. in the nutrient broth without antibiotics only. only in the broth containing both antibiotics. in the broth containing tetracycline, but not in the broth containing ampicillin. in the nutrient broth plus ampicillin, but not in the broth containing tetracycline.

in all four types of broth.

Which of the following is an example of "recombinant DNA technology"? combining alternate alleles of a gene in a single cell cloning genes from homologous pairs of chromosomes introducing a human gene into a bacterial plasmid manipulating a meiotic crossing-over event alternate alleles assorting independently

introducing a human gene into a bacterial plasmid

made in segments daughter strand elongates away from replication fork multiple primers needed

lagging strand

The new DNA strand that grows continuously in the 5' to 3' direction is called the

leading strand

daughter strand elongates toward replication fork only one primer needed made continuously

leading strand

Gel electrophoresis separates DNA fragments on the basis of what characteristic? restriction sites charge length mutations sequence

length

During DNA replication, which of the following enzymes covalently connects segments of DNA? helicase DNA polymerase III ligase DNA polymerase I primase

ligase

Part complete Short segments of newly synthesized DNA are joined into a continuous strand by _____. DNA polymerase helicase ligase primase single-strand binding protein

ligase

Short segments of newly synthesized DNA are joined into a continuous strand by _____. helicase primase DNA polymerase single-strand binding protein ligase

ligase

In nucleotide excision repair, damaged DNA is excised by what enzyme(s)? DNA polymerases nuclease primase helicase ligase

nuclease

Part complete The spontaneous loss of amino groups from adenine in DNA results in hypoxanthine, an uncommon base, opposite thymine. What combination of proteins could repair such damage? topoisomerase, primase, DNA polymerase DNA ligase, replication fork proteins, adenylyl cyclase topoisomerase, helicase, single-strand binding protein nuclease, DNA polymerase, DNA ligase

nuclease, DNA polymerase, DNA ligase

Which of the following lists of structures correctly represents the order of increasingly higher levels of organization of chromatin? looped domain, nucleosome, 30-nm chromatin fiber nucleosome, 30-nm chromatin fiber, looped domain looped domain, 30-nm chromatin fiber, nucleosome 30-nm chromatin fiber, nucleosome, looped domain nucleosome, looped domain, 30-nm chromatin fiber

nucleosome, 30-nm chromatin fiber, looped domain

This is an image of a(n) _____.

nucleotide

What process repairs damage to a preexisting double helix? nucleotide excision repair proofreading operon repair mismatch repair transformation

nucleotide excision repair

E. coli cells grown on 15N medium are transferred to 14N medium and allowed to grow for two more generations (two rounds of DNA replication). DNA extracted from these cells is centrifuged. What density distribution of DNA would you expect in this experiment? one high-density and one intermediate-density band one high-density and one low-density band one low-density and one intermediate-density band one intermediate-density band

one low-density and one intermediate-density band

A polynucleotide contains a sugar/phosphate backbone, where the sugar of one nucleotide binds to the phosphate of the next, and so on.

phosphate

The letter A indicates a _____.

phosphate group

Part complete Which of the following enzymes synthesizes short segments of RNA? helicase DNA polymerase III ligase DNA polymerase I primase

primase

What is the function of topoisomerase? unwinding of the double helix stabilizing single-stranded DNA at the replication forke longating new DNA at a replication fork by adding nucleotides to the existing chain adding methyl groups to bases of DNA relieving strain in the DNA ahead of the replication for

relieving strain in the DNA ahead of the replication for

During DNA replication, an open section of DNA, in which a DNA polymerase can replicate DNA, is called a

replication fork

Part complete The action of helicase creates _____. primers and replication bubbles primers and DNA fragments DNA fragments and replication bubbles replication forks and replication bubbles

replication forks and replication bubbles

The action of helicase creates _____. DNA fragments and replication bubbles replication forks and replication bubbles DNA fragments and replication forks primers and replication bubbles primers and DNA fragments

replication forks and replication bubbles

The action of helicase creates _____. primers and DNA fragments DNA fragments and replication bubbles primers and replication bubbles DNA fragments and replication forks replication forks and replication bubbles

replication forks and replication bubbles

Polytene chromosomes of Drosophila salivary glands each consist of multiple identical DNA strands that are aligned in parallel structures. How could these arise? meiosis followed by mitosis special association with histone proteins replication without separation fertilization by multiple sperm replication followed by mitosis

replication without separation

binds after the replication fork prevents H-bonds between bases

single-strand binding protein

Part complete Which of the following help(s) to hold the DNA strands apart while they are being replicated? ligase DNA polymerase single-strand binding proteins primase nuclease

single-strand binding proteins

In his work with pneumonia-causing bacteria and mice, Griffith found that __________. the protein coat from pathogenic cells was able to transform nonpathogenic cells the polysaccharide coat of bacteria caused pneumonia heat-killed pathogenic cells caused pneumonia some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic

some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic

The sugar and phosphate groups are the same for all DNA nucleotides. The base is the one part that changes.

sugar and phosphate only

You can tell that this is an image of a DNA nucleotide and not an RNA nucleotide because you see a _____. sugar with two, and not three, oxygen atoms uracil nitrogenous base, not a thymine nitrogenous base double-stranded molecule, not a single-stranded molecule phosphate group, not a uracil thymine nitrogenous base, not a uracil nitrogenous base

sugar with two, and not three, oxygen atoms

What are the repetitive DNA sequences present at the ends of eukaryotic chromosomes called? sarcomeres polypeptides telomeres centromeres chromomeres

telomeres

An old DNA strand is used as a _____ for the assembly of a new DNA strand. complement model template source of nucleotides primer

template

An old DNA strand is used as a _____ for the assembly of a new DNA strand. complement source of nucleotides template primer model

template

An old DNA strand is used as a _____ for the assembly of a new DNA strand. primer model template source of nucleotides complement

template

Part complete The leading and the lagging strands of DNA formed during DNA replication differ in that the lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together. the leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end. the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction. the leading strand is synthesized at twice the rate of the lagging strand

the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction.

difference between ATP and the nucleoside triphosphates used during DNA synthesis is that triphosphate monomers are active in the nucleoside triphosphates, but not in ATP. ATP contains three high-energy bonds; the nucleoside triphosphates have two. the nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar ribose. ATP is found only in human cells; the nucleoside triphosphates are found in all animal and plant cells .the nucleoside triphosphates have two phosphate groups; ATP has three phosphate groups.

the nucleoside triphosphates have the sugar deoxyribose; ATP has the sugar ribose.

It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information based on which of the following characteristics? the sequence of bases complementary pairing of bases different five-carbon sugars phosphate-sugar backbones

the sequence of bases

Which of these nitrogenous bases is found in DNA but not in RNA? thymine cytosine adenine uracil guanine

thymine

In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand.

thymine ... cytosine

In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand. thymine ... cytosine guanine ... adenine cytosine ... uracil uracil ... cytosine cytosine ... thymine

thymine ... cytosine

In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand. thymine ... cytosineuracil ... cytosineguanine ... adeninecytosine ... thyminecytosine ... uracil

thymine ... cytosine

What is the function of DNA polymerase III? to add nucleotides to the 3' end of a growing DNA strand to rejoin the two DNA strands (one new and one old) after replication to seal together the broken ends of DNA strands to unwind the DNA helix during replication to degrade damaged DNA molecules

to add nucleotides to the 3' end of a growing DNA strand

binds ahead of the replication fork breaks covalent bonds in DNA backbone

topoisomerase