A) mix a heat-killed pathogenic stress, overload of bacteria with a living nonpathogenic stress, overload can convert some that the living cells right into the pathogenic form.

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B) mix a heat-killed nonpathogenic stress, overload of bacteria v a life pathogenic strain renders the pathogenic stress, overload nonpathogenic.

C) Infecting mice through nonpathogenic strains of bacteria makes them resistant to pathogenic strains.

D) mice infected through a pathogenic stress, overload of bacteria can spread the epidemic to various other mice.



2) how do we describe transformation in bacteria?

A) the development of a strand of DNA native an RNA molecule

B) the creation of a strand the RNA from a DNA molecule

C) the epidemic of cells by a phage DNA molecule

D) adaptation of external DNA right into a cell



3) After mix a heat-killed, phosphorescent (light-emitting) strain of bacteria with a living, nonphosphorescent strain, you find that several of the living cells are now phosphorescent. I m sorry observation(s) would carry out the ideal evidence that the ability to phosphoresce is a heritable trait?

A) proof that DNA was passed native the heat-killed stress, overload to the life strain

B) evidence that protein passed native the heat-killed stress, overload to the life strain

C) especially bright phosphorescence in the living strain

D) phosphorescence in progeny of the life cells



4) In make the efforts to determine whether DNA or protein is the hereditary material, Hershey and also Chase made use of i beg your pardon of the complying with facts?

A) DNA has sulfur, conversely, protein does not.

B) DNA has phosphorus, vice versa, protein go not.

C) DNA includes nitrogen, whereas protein walk not.

D) DNA includes purines, vice versa, protein includes pyrimidines.



5) i m sorry of the adhering to investigators was (were) responsible for the adhering to discovery?

In DNA from any species, the lot of adenine amounts to the lot of thymine, and also the lot of guanine equals the amount of cytosine.

A) Alfred Hershey and Martha Chase

B) Oswald Avery, Maclyn McCarty, and Colin MacLeod

C) Erwin Chargaff

D) Matthew Meselson and Franklin Stahl



6) Cytosine makes up 42% the the nucleotides in a sample the DNA native an organism. Roughly what portion of the nucleotides in this sample will be thymine?

A) 8%

B) 16%

C) 42%

D) 58%



7) that became obvious to Watson and also Crick after perfect of their version that the DNA molecule could lug a large amount the hereditary details in which of the following?

A) succession of bases

B) phosphate-sugar backbones

C) safety pairing that bases

D) side groups of nitrogenous bases



8) In an analysis of the nucleotide ingredient of DNA, i m sorry of the complying with will it is in found?

A) A = C

B) A = G and also C = T

C) A + C = G + T

D) G + C = T + A



9) for a scientific research fair project, 2 students determined to repeat the Hershey and Chase experiment, v modifications. They decided to brand the nitrogen that the DNA, quite than the phosphate. They reasoned that each nucleotide has only one phosphate and also two to 5 nitrogens. Thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates. Why won"t this experiment work?

A) there is no radiation isotope the nitrogen.

B) radioactive nitrogen has actually a half-life the 100,000 years, and the material would be as well dangerous for too long.

C) Although there are much more nitrogens in a nucleotide, labeled phosphates actually have actually sixteen extra neutrons; therefore, they are much more radioactive.

D) Amino acids (and for this reason proteins) additionally have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.



10) Hershey and Chase collection out to determine what molecule offered as the unit of inheritance. They perfect a collection of experiment in i beg your pardon E. Coli was infected through a T2 virus. I m sorry molecular ingredient of the T2 virus actually ended up inside the cell?

A) protein


C) ribosome




11) In the polymerization the DNA, a phosphodiester bond is formed in between a phosphate group of the nucleotide being included and _____ that the critical nucleotide in the polymer.

A) the 5" phosphate B) C6 C) the 3" oh D) a nitrogen indigenous the nitrogen-containing basic



12) Replication in prokaryotes different from replication in eukaryotes because that which of the complying with reasons?

A) prokaryotic chromosomes have actually histones, whereas eukaryotic chromosomes execute not.

B) prokaryotic chromosomes have actually a solitary origin that replication, whereas eukaryotic chromosomes have many.

C) The rate of elongation during DNA replication is slow in prokaryotes than in eukaryotes.

D) Prokaryotes create Okazaki fragments during DNA replication, but eukaryotes execute not.



13) What is expected by the description "antiparallel" about the strands that comprise DNA?

A) The twisting nature that DNA creates nonparallel strands. B) The 5" come 3" direction that one strand runs respond to to the come direction that the various other strand. C) base pairings develop unequal spacing between the 2 DNA strands. D) One strand includes only purines and also the other includes only pyrimidines.



14) mean you are detailed with an actively dividing society of E. Coli bacteria come which radiation thymine has been added. What would happen if a cell replicates when in the existence of this radiation base?

A) one of the daughter cells, however not the other, would have actually radioactive DNA.

B) no of the two daughter cells would be radioactive.

C) All 4 bases that the DNA would be radioactive.

D) DNA in both daughter cells would certainly be radioactive.



15) In E. Coli, over there is a mutation in a gene called dnaB that transforms the helicase that usually acts in ~ the origin. Which of the complying with would you expect as a result of this mutation?

A) additional proofreading will certainly occur.

B) No replication fork will certainly be formed.

C) Replication will occur via RNA polymerase alone.

D) Replication will call for a DNA design template from an additional source.



16) In E. Coli, which enzyme catalyzes the elongation that a brand-new DNA strand in the → direction?

A) primase B) DNA ligase C) DNA polymerase III D) helicase



17) eukaryotic bio telomeres replicate in different ways than the remainder of the chromosome. This is a an effect of which of the following?

A) the advancement of telomerase enzyme B) DNA polymerase that cannot replicate the top strand template to that is 5" finish C) gaps left in ~ the 5" finish of the lagging strand D) gaps left at the 3" end of the lagging strand because of the need for a inside wall



18) just how does the enzyme telomerase satisfy the an obstacle of replicating the ends of direct chromosomes?

A) the adds a solitary cap framework that resists deterioration by nucleases. B) it causes specific double-strand DNA division that result in dull ends top top both strands. C) the catalyzes the lengthening of telomeres, compensating because that the shortening that can occur throughout replication without telomerase activity. D) the adds many GC pairs, which withstand hydrolysis and maintain chromosome integrity.



19) The DNA of telomeres has been highly conserved throughout the advancement of eukaryotes. This most most likely reflects _____.

A) the low frequency of mutations emerging in this DNA B) ongoing evolution that telomeres C) that brand-new mutations in telomeres have been helpful D) a an important function that telomeres



20) at a particular area the a chromosome, the succession of nucleotides listed below is current where the chain opens to kind 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 beginning at the underlined T (T) the the template. I m sorry of the following represents the primer sequence?

A) 5" G C C T A G G 3" B) 5" A C G T T A G G 3" C) 5" A C G U U A G G 3" D) 5" G C C U A G G 3"



21) In E. Coli, to fix a thymine dimer through nucleotide excision repair, in i m sorry order carry out the essential enzymes act?

A) nuclease, DNA polymerase III, RNA primase

B) helicase, DNA polymerase I, DNA ligase

C) DNA ligase, nuclease, helicase

D) nuclease, DNA polymerase I, DNA ligase



22) In E. Coli, what is the role of DNA polymerase III?

A) come unwind the DNA helix throughout replication B) come seal with each other the damaged ends the DNA strands C) to include nucleotides to the end of a growing DNA strand D) to degrade damaged DNA molecules



23) The difference in between ATP and also the nucleoside triphosphates used throughout DNA synthetic is that _____.

A) the nucleoside triphosphates have actually the street deoxyribose; ATP has actually the street ribose

B) the nucleoside triphosphates have two phosphate groups; ATP has three phosphate groups

C) ATP contains three high-energy bonds; the nucleoside triphosphates have actually two

D) ATP is uncovered only in person cells; the nucleoside triphosphates are uncovered in all animal and also plant cells



24) The leading and also the lagging strands different in the _____.

A) the top strand is synthesized in the exact same direction together the movement of the replication fork, and also the lagging strand is synthesized in the contrary direction B) the top strand is synthesized by including nucleotides come the finish of the growing strand, and also the lagging strand is synthesized by including nucleotides to the end C) the lagging strand is synthesized continuously, conversely, the leading strand is synthesized in brief fragments the are at some point stitched with each other D) the leading strand is synthesized at double the rate of the lagging strand



25) A brand-new DNA strand elongates just in the 5" come 3" direction since _____.

A) DNA polymerase begins including nucleotides at the 5" finish of the layout B) the polarity that the DNA molecule prevents addition of nucleotides in ~ the 3" finish C) replication must progress towards the replication fork D) DNA polymerase can add nucleotides just to the cost-free 3" end



26) What is the function of topoisomerase?

A) relieving strain in the DNA ahead of the replication fork

B) elongating new DNA at a replication fork by adding nucleotides come the currently chain

C) unwinding of the double helix

D) stabilizing single-stranded DNA in ~ the replication fork



27) What is the role of DNA ligase in the elongation of the lagging strand throughout DNA replication?

A) it synthesizes RNA nucleotides to do a primer.

B) It joins Okazaki fragments together.

C) it unwinds the parental dual helix.

D) the stabilizes the unwound parental DNA.



28) i beg your pardon of the complying with help(s) to organize the DNA strands apart while they room being replicated?

A) primase

B) ligase

C) DNA polymerase

D) single-strand DNA binding proteins



29) individuals with the disorder xeroderma pigmentosum are hypersensitive come sunlight. This occurs since their cell cannot_____.

A) replicate DNA

B) experience mitosis

C) exchange DNA with other cells

D) fix thymine dimers



30) i beg your pardon of the complying with would you mean of a eukaryote doing not have telomerase?

A) a high probability that somatic cells coming to be cancerous

B) an inability to develop Okazaki fragments

C) an inability to fix thymine dimers

D) a reduction in chromosome length in gametes



31) In the so late 1950s, Meselson and Stahl prospered bacteria in a tool containing "heavy" nitrogen (15N) and also then moved them to a tool containing 14N. Which of the results in the figure over would be meant after one round of DNA replication in the presence of 14N?

A) A B) B C) C D) D



32) A space probe returns v a society of a virus found ~ above a distant planet. Analysis shows the it is a carbon-based life-form that has actually DNA. You prosper the cell in 15N medium for number of generations and then carry them to 14N medium. Which sample in the figure over would you suppose if the DNA to be replicated in a conservative manner?

A) A B) B C) C D) D



33) ~ the first replication to be observed in their experiments trial and error the nature that DNA replication, Meselson and Stahl can be i was sure of i m sorry of the following conclusions?

A) Replication is semi-conservative.

B) Replication is not dispersive.

C) Replication is no conservative.

D) Replication is no dispersive no one conservative.



34) girlfriend briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated indigenous the bacteria, the DNA separates into two classes. One course of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and also the various other includes quick stretches the DNA (several hundred to a few thousand nucleotides in length). These 2 classes of DNA probably represent _____.

A) top strands and also Okazaki fragments

B) lagging strands and Okazaki fragments

C) Okazaki fragments and also RNA primers

D) top strands and RNA primers



35) within a double-stranded DNA molecule, adenine develops hydrogen bonds v thymine and cytosine forms hydrogen bonds v guanine. This arrangement _____.

A) permits variable width of the twin helix

B) patent complementary base pairing

C) determines the tertiary framework of a DNA molecule

D) determines the kind of protein produced



36) Semiconservative replication involves a template. What is the template?

A) single-stranded binding proteins

B) DNA polymerase

C) one strand of the DNA molecule

D) an RNA molecule



37) DNA is synthesized with a process known as _____.

A) semiconservative replication

B) conservative replication

C) translation

D) transcription



38) that performed standard experiments that sustained the semiconservative version of DNA replication?

A) Watson and Crick

B) Meselson and also Stahl

C) Hershey and Chase

D) Franklin and Wilkins



39) DNA contains the template required to copy itself, but it has no catalytic activity in cells. What catalyzes the development of phosphodiester bonds between adjacent nucleotides in the DNA polymer gift formed?

A) ribozymes

B) DNA polymerase


D) deoxyribonucleotide triphosphates



40) What gives the energy for the polymerization reactions in DNA synthesis?


B) DNA polymerase

C) breaking the hydrogen bonds in between complementary DNA strands

D) the deoxyribonucleotide tree phosphate substrates



41) refer to the number above. What bases will be included to the primer as DNA replication proceeds? The bases should show up in the brand-new strand in the order that they will certainly be added starting at the 3" finish of the primer.

A) C, A, G, C, A, G, A B) T, C, T, G, C, T, G C) A, G, A, C, G, A, C D) G, T, C, G, T, C, T



42) What is the difference in between the top strand and the lagging strand in DNA replication?

A) The leading strand is synthesized in the 3"→5" direction in a discontinuous fashion, if the lagging strand is synthesized in the 5"→3" direction in a consistent fashion. B) The leading strand is synthesized repeatedly in the5"→3" direction, when the lagging strand is synthesized discontinuously in the 5" → 3" C) The leading strand requires an RNA primer, conversely, the lagging strand go not. D) there are various DNA polymerases involved in elongation that the top strand and the lagging strand.



43) What is a major difference between eukaryotic DNA replication and prokaryotic DNA replication?

A) prokaryotes replication go not need a primer. B) prokaryotes chromosomes have a solitary origin of replication, while eukaryotic bio chromosomes have actually multiple beginnings of replication. C) DNA replication in prokaryotic cells is conservative. DNA replication in eukaryotic bio cells is semi-conservative. D) DNA polymerases the prokaryotes can include nucleotides come both 3’and 5’ends the DNA strands, if those that eukaryotes function only in the 5’ → 3’



44) What is a telomere?

A) the system that holds two sister chromatids together

B) DNA replication during telophase

C) the site of beginning of DNA replication

D) the end of direct chromosomes



45) Telomere shortening place a border on the number of times a cell have the right to divide. Research has displayed that telomerase can prolong the life expectancy of cultured human cells. Exactly how might including telomerase affect cellular aging?

A) Telomerase will rate up the rate of cabinet proliferation.

B) Telomerase eliminates telomere shortening and retards aging.

C) Telomerase shortens telomeres, which delays cellular aging.

D) Telomerase would have no result on moving aging.



46) Telomere shortening is a difficulty in which types of cells?

A) just prokaryotic cells

B) only eukaryotic cells

C) cell in prokaryotes and eukaryotes



47) i m sorry of the adhering to cells have decreased or very tiny active telomerase activity?

A) many normal somatic cells

B) many normal germ cells

C) most cancer cells



48) Researchers discovered E. Coli that had mutation rates one hundred times greater than normal. I m sorry of the adhering to is the most likely cause of this results?

A) The single-stranded binding proteins were malfunctioning. B) There to be one or an ext mismatches in the RNA primer. C) The proofreading mechanism of DNA polymerase was not functioning properly. D) The DNA polymerase to be unable to add bases to the finish of the cultivation nucleic acid chain.



49) In a healthy cell, the price of DNA fix is equal to the price of DNA mutation. Once the rate of repair lags behind the rate of mutation, what is a feasible fate the the cell?

A) The cell deserve to be reinvented to a cancer cell. B) RNA may be used instead of DNA as inheritance material. C) The cabinet will come to be embryonic. D) DNA synthesis will proceed by a brand-new mechanism.



50) which of the complying with statements defines a eukaryotic chromosome?

A) a solitary strand the DNA

B) a series of nucleosomes wrapped about two DNA molecules

C) a chromosome with various numbers of gene in different cell varieties of one organism

D) a single linear molecule the double-stranded DNA add to proteins



51) If a cell were unable to create histone proteins, which of the adhering to would it is in a likely effect?

A) There would certainly be an increase in the lot of "satellite" DNA developed during centrifugation.

B) The cell"s DNA couldn"t be packed into its nucleus.

C) Spindle fibers would certainly not kind during prophase.

D) Amplification of other genes would compensate for the absence of histones.



52) i m sorry of the following statements is true the histones?

A) every nucleosome is composed of two molecules that histone H1.

B) Histone H1 is not current in the nucleosome bead; instead, the draws the nucleosomes together.

C) The carboxyl finish of each histone extends exterior from the nucleosome and also is called a "histone tail."

D) Histones are found in mammals, yet not in other animals or in plants or fungi.



53) Why execute histones tie tightly to DNA?

A) Histones room positively charged, and also DNA is negative charged.

B) Histones room negatively charged, and DNA is positively charged.

C) Both histones and also DNA room strongly hydrophobic.

D) Histones space covalently attached to the DNA.



54) which of the adhering to represents the stimulate of increasingly greater levels of organization of chromatin?

A) nucleosome, 30-nm dyed fiber, looped domain

B) looped domain, 30-nm chromatin fiber, nucleosome

C) nucleosome, looped domain, 30-nm dyed fiber

D) 30-nm chromatin fiber, nucleosome, looped domain



55) i beg your pardon of the following statements defines chromatin?

A) Heterochromatin is composed of DNA, conversely, euchromatin is made of DNA and RNA.

B) Both heterochromatin and euchromatin are discovered in the cytoplasm.

C) Heterochromatin is highly condensed, whereas euchromatin is less compact.

D) Euchromatin is no transcribed, vice versa, heterochromatin is transcribed.



56) i beg your pardon of the adhering to is most vital for the association in between histones and also DNA?

A) Histones are small proteins.

B) Histones are extremely conserved (that is, histones are very comparable in every eukaryote).

C) There room at least five various histone proteins in every eukaryote.

D) Histones space positively charged.



57) In E. Coli replication the enzyme primase is used to attach a 5 to 10 basic ribonucleotide strand complementary come the parental DNA strand. The RNA strand serves as a starting point for the DNA

polymerase that replicates the DNA. If a mutation developed in the primase gene, i m sorry of the following would friend expect?

A) Replication would only take place on the top strand.

B) Replication would certainly only take place on the lagging strand.

C) Replication would not take place on either the leading or lagging strand.

D) Replication would not be affected as the enzyme primase in connected with RNA synthesis.



58) Hershey and also Chase provided a DNA-based virus for your work. What would certainly the results have actually been if they had actually used an RNA virus?

A) v an RNA virus radioactive protein would certainly have been in the final pellet. B) v an RNA virus radioactive RNA would have been in the last pellet. C) through an RNA virus no sample would have had a radiation pellet. D) with an RNA virus the protein covering would have actually been radiation in both samples.



59) The lagging strand is defined by a series of brief segments that DNA (Okazaki fragments) that will be joined with each other to form a perfect lagging strand. The experiments that caused the exploration of Okazaki

fragments gave evidence for which of the complying with ideas?

A) DNA polymerase is a directional enzyme the synthesizes leading and also lagging strands throughout replication.

B) DNA is a polymer consisting of four monomers: adenine, thymine, guanine, and cytosine.

C) DNA is the hereditary material.

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D) bacter replication is fundamentally various from eukaryotic replication. The vital shouldn’t be method longer than the distractors.