Biotechnology Midterm
1. Which statement best describes the central dogma of genetics? a. Genes are made of DNA, expressed as an RNA intermediary that is decoded to make proteins. b. The central dogma only applies to yellow and green peas from Mendel's experiments. c. Genes are made of RNA, expressed as a DNA intermediary, which is decoded to make proteins. d. Genes made of DNA are directly decoded to make proteins. e. The central dogma only applies to animals.
a
10. Besides a high voltage shock, what is another method to make E. coli competent to take up "naked" DNA? a. high concentrations of calcium ions followed by high temperature b. high concentrations of calcium ions and several hours on ice c. large amounts of DNA added directly to a bacterial culture growing at 37 °C d. high concentrations of minerals followed by high temperature e. A high voltage shock is the only way to make E. coli competent.
a
10. Which of the following statements about PCR is incorrect? a. The DNA template is denatured using helicase. b. PCR is used to obtain millions of copies of a specific region of DNA. c. A thermostable DNA polymerase is used because of the high temperatures required in PCR. d. Template DNA, a set of primers, deoxynucleotides, a thermostable DNA polymerase, and a thermocycler are the important components in PCR. e..Primers are needed because DNA polymerase cannot initiate synthesis, but can only elongate from an existing 3′-OH.
a
10. Which one of the following is often used to establish family trees for organisms because it is present in all organisms and does not accumulate mutations quickly? a. rRNA b. fibrinopeptides c. hemoglobin d. chloroplasts e. mitochondrial DNA
a
11. What is the main advantage for studying cells in culture rather than in a whole organism? a. Cell lines in culture are easily manipulated genetically to introduce new genes or delete other genes. b. Cell lines are not very stable and therefore, it is more advantageous to study cells within the organism itself. c. There is no advantage to studying cells in a cell line rather than in a live organism. d. The information obtained from studying cell lines as opposed to live organisms is not relevant to what happens in vivo. e. None of the above is the main advantage.
a
12. Which of the following statements about gene libraries is correct? a. Genes in a library can be compared to genes from other organisms by hybridization with a probe. b. A gene library is only necessary to maintain known genes. c. Every gene in the library must be sequenced first in order to compare genes in the library to genes from other organisms. d. Gene libraries are only created for eukaryotic organisms. e. Gene libraries can only be created in prokaryotes.
a
13. Which of the following statements does not highlight a difference in eukaryotic and prokaryotic translation? a. The first methionine in eukaryotic translation contains a formyl group. b. In eukaryotes, mRNA is made in the nucleus but translated in the cytoplasm. c. Prokaryotes often couple transcription and translation, forming a polysome. d. Eukaryotic mRNA does not have a Shine-Dalgarno sequence, but prokaryotic mRNA does. e. Many eukaryotic proteins are chemically modified after translation, which is a much rarer phenomenon in prokaryotes.
a
14. What is a riboswitch? a. an mRNA sequence that binds directly to an effector molecule to control the translation of the mRNA into protein b. an enzyme that converts ribozymes into deoxyribozymes c. the effector molecule responsible for translational control of a particular mRNA d. an RNA molecule that switches between being translated into protein or being a ribozyme e. none of the above
a
14. Which statement best describes the F plasmid? a. F plasmids contain genes for formation of a specialized pilus that forms a conjugation bridge between two cells for the purpose of transferring genetic material. b. The F plasmid does not have an origin of replication and can therefore not replicate itself. c. The primary host for the F plasmid is Saccharomyces cerevisiae. d. The F plasmid is not important for biotechnology research. e. All of the above statements describe the F plasmid.
a
2. For which of the following nitrogenous bases does DNA substitute thymine? a. uracil b. adenine c. guanine d. cytosine e. inosine
a
2. What is contig mapping? a. determination of regions that overlap from one clone to the next in a library b. the distance in base pairs between two markers c. the use of landmarks in the genes to put together sequencing data d. the relative order of specific markers in a genome e. the mapping that determines if a library sequence is from one continuous gene or two gene segments cloned into one vector
a
2. Why is an RNA primer necessary during replication? a. DNA polymerase III requires a 3′-OH to elongate DNA. b. An RNA primer is not needed for elongation. c. DNA polymerase requires a 5′-phosphate before it can elongate the DNA. d. A DNA primer is needed for replication instead of an RNA primer. e. An RNA primer is only needed once the DNA has been elongated and DNA polymerase is trying to fill in the gaps.
a
3. How are restriction enzymes and ligase used in biotechnology? a. Restriction enzymes cut DNA at specific locations, producing ends that can be ligated back together with ligase. b. Only restriction enzymes that produce blunt ends after cutting DNA can be ligated with ligase. c. Only restriction enzymes that produce sticky ends on the DNA can be ligated with ligase. d. Restriction enzymes can both cut DNA at specific sites and ligate them back together. e. Restriction enzymes randomly cut DNA, and the cut fragments can be ligated back together with ligase.
a
4. How can antisense RNA be expressed within a cell? a. The target gene can be cloned inversely into a vector and under the control of an inducible promoter. b. The antisense RNA cannot be expressed within a cell and instead must be delivered via liposomes. c. Antisense RNA can be expressed within cells, but this is unfavorable because of the high degree of nonspecific interactions. d. No system has been designed to express antisense RNA within a cell. e. None of the above is correct.
a
6. What is the difference between Southern and Northern hybridizations? a. Southern blots hybridize a DNA probe to a digested DNA sample but northern blots hybridize a DNA probe to, usually, mRNA. b. Southern blots use an RNA probe to hybridize to DNA but Northern blots use an RNA probe to hybridize to RNA. c. Southern blots determine if a particular gene is being expressed but Northern blots determine the homology between mRNA and a DNA probe. d. Southern blots determine the homology between mRNA and a DNA probe but Northern blots determine if a particular gene is being expressed. e. Southern and Northern blots are essentially the same technique performed in different hemispheres of the world.
a
7. Which of the following is not a step in the chemical synthesis of DNA? a. The 3′ phosphate group is added using phosphorylase. b. The addition of a blocking compound to protect the 3′ phosphite from reacting improperly. c. The 5′-OH is phosphorylated by bacteriophage T4 kinase. d. The addition of acetic anhydride and dimethylaminopyridine to cap the 5′-OH group of unreacted nucleotides. e. The amino groups on the bases are modified by other chemical groups to prevent the bases from reacting during the elongation process.
a
9. What information has been obtained through the creation of RNAi libraries? a. the function of unknown proteins by degrading all of the mRNA for that protein b. the mechanism by which E. coli delivers dsRNA to C. elegans c. the mechanism by which heterochromatic formation occurs after some RNAi d. all of the above e. none of the above
a
9. Which of the following components terminates the chain in a sequencing reaction? a. dideoxynucleotides b. Klenow polymerase c. DNA polymerase III d. deoxynucleotides e. DNA primers
a
10. What is a ribozyme? a. an enzyme that cuts ribosomes b. an RNA molecule that binds to specific targets and catalyzes reactions c. an enzyme that catalyzes the degradation of dsRNA d. an RNA molecule that catalyzes the degradation of ribonucleases e. none of the above
b
14. Why do mitochondria and chloroplasts contain their own genes? a. They are free-living prokaryotes, able to survive outside of the host cell. b. They are thought to have once been free-living organisms similar to bacteria that formed a symbiotic relationship with a unicellular eukaryote. c. They do not contain their own genetic material. d. They contain genetic material but do not make their own proteins. e. None of the above is correct.
b
3. What are the functions of the two essential subunits of DNA polymerase III? a. Both subunits synthesize the lagging strand only. b. One subunit links nucleotides and the other ensures accuracy. c. They both function as a clamp to hold the complex to the DNA. d. The subunits function to break apart the bonds in the DNA strand. e. One subunit removes the RNA primer and the other synthesizes DNA.
b
3. Which method was used to sequence the human genome? a. cytogenetic mapping b. shotgun sequencing c. chromosome walking d. radiation hybrid mapping e. All of the above were used in combination to complete the project.
b
3. Which of the following is not necessary during Rho-independent termination of transcription? a. RNA polymerase b. Rho protein c. hairpin structure d. repeating A's in the DNA sequence e. All of the above are necessary
b
5. Why does the GC content of a particular DNA molecule affect the melting of the two strands? a. The G and C bond only requires two hydrogen bonds, thus requiring a lower temperature to "melt" the DNA. b. Because G and C base-pairing requires three hydrogen bonds and a higher temperature is required to "melt" the DNA. c. The percentage of As and Ts in the molecule is more important to melting temperature than the percentage of Gs and Cs. d. The nucleotide content of a DNA molecule is not important to know for biotechnology and molecular biology research. e. None of the above.
b
7. How is data mining useful to biotechnology research? a. It allows researchers to determine sequence similarity, which usually translates into functional similarity. b. Data mining allows researchers to use computers to study, sort, and compile the vast amounts of raw data generated through bioinformatics. c. Data mining is the act of gathering the raw data from research projects such as sequencing into one central location. d. Data mining usually provides too much information, which only slows down the research project and is therefore not very useful. e. none of the above
b
7. What might be a use for fluorescence in situ hybridization (FISH)? a. For identification of a specific gene in a DNA extraction by hybridization to a DNA probe. b. For identification of a specific gene by hybridization to a DNA probe within live cells that have had their DNA denatured by heat. c. For identification of an mRNA within an RNA extraction by hybridization to a DNA probe. d. For identification of both mRNA and DNA in cellular extracts using an RNA probe. e. None of the above.
b
7. Which of the following is not a method for delivering dsRNA for RNAi into Drosophila and C. elegans cells? a. ingestion of transgenic bacteria that express dsRNA b. cDNA library clone c. injection of dsRNA into eggs d. bathing in a solution of pure dsRNA e. injection of dsRNA into cell culture lines
b
8. What mechanism does yeast utilize to control mating type in the cells? a. Yeast is only able to reproduce through mitosis. b. The MAT locus in the yeast genome contains two divergent genes that encode for the pheromones a and α, along with the pheromone receptors. c. The mating type of yeast is determined by pheromones called b and β. d. There are no mechanisms to control mating type in yeast because all of the cells are structurally the same. e. Yeast mating types are generally referred to as either male or female.
b
9. Which of the following statements about mutations is not true? a. Mutations occur in all organisms at the same rate. b. DNA polymerase never produces mutations during replication because of the proofreading ability of this enzyme. c. Mutations often occur at methylated cytosine residues. d. Mutations such as duplications or deletions occur due to repetitive sequences causing strand slippage. e. When comparing mutation rates to coding capacity, mutation rates are usually the same for most organisms, which suggests a mechanism to control the rate.
b
1. Which of the following statements about DNA isolation from E. coli is not correct? a. Chemical extraction using phenol removes proteins from the DNA. b. RNA is removed from the sample by RNase treatment. c. Detergent is used to break apart plant cells to extract DNA. d. Lysozyme digests peptidoglycan in the bacterial cell wall. e. Centrifugation separates cellular components based on size.
c
10. Which of the following statements about protein translation is not correct? a. The genetic code is read in triplets, also called codons. b. The enzyme, aminoacyl tRNA synthetase, is responsible for adding the amino acid to the tRNA. c. The anticodon of the tRNA must recognize the codon on the mRNA exactly. d. Because of the wobble effect, a tRNA for one amino acid often recognizes multiple codons in the mRNA. e. For the most part, the genetic code is considered universal.
c
11. Which of the following is a large ribozyme? a. hairpin ribozyme b. hammerhead ribozyme c. Twort ribozyme d. hepatitis delta virus e. Varkud satellite ribozyme
c
11. Which of the following statements about DNA microarrays is not correct? a. Fluorescently labeled mRNA from the organism hybridizes to the DNA on the glass slide. b. DNA microarrays contain thousands of DNA segments on a support, such as a glass slide. c. Hybridization to a DNA microarray can only occur once. d. The amount of fluorescence correlates with the amount of mRNA in the sample. e. The data obtained from DNA microarrays represents a global view of gene expression, even under particular growth conditions.
c
15. Which of the following is not the correct composition of each subunit of the ribosome? a. 30S = 16 rRNA + 21 proteins b. 50S = 5S + 23S + 34 proteins c. 30S = 5S + 23S + 21 proteins d. 70S = 30S + 50S + tRNA i fMet e. All of the above are correct.
c
15. Which one of the following fusion proteins does not require some kind of chemical substrate to observe activity? a. luciferase b. alkaline phosphatase c. green fluorescent protein d. β-galactosidase e. all of the above
c
2. What is the difference between DNA and RNA? a. DNA contains a phosphate group, but RNA does not. b. Both DNA and RNA contain a sugar, but only DNA has a pentose. c. The sugar ring in RNA has an extra hydroxyl group that is missing in the pentose of DNA. d. DNA consists of five different nitrogenous bases, but RNA only contains four different bases. e. RNA only contains pyrimidines and DNA only contains purines.
c
2. Which biological function is not controlled by antisense RNA? a. iron metabolism in bacteria b. the circadian rhythm of Neurospora c. replication of prokaryotic genomic DNA d. replication of ColE1 plasmid e. developmental control of basic fibroblast growth factor
c
5. Which of the following statements is incorrect regarding DNA replication? a. Rolling circle and theta replication are common for prokaryotes and viruses. b. Each round of replication for linear chromosomes, such as in eukaryotes, shortens the length of the chromosome. c. Prokaryotic chromosomes have multiple origins of replication. d. Eukaryotic replication only occurs during the S-phase of the cell cycle. e. Eukaryotic chromosomes have multiple origins of replication.
c
5. Which statement about Escherichia coli is not correct? a. E. coli is called "the workhorse of molecular biology." b. E. coli can grow in a simple solution of water, a carbon source, and mineral salts. c. All E. coli strains are pathogenic, and therefore must be handled accordingly. d. The chromosome of E. coli consists of one circular DNA molecular containing approximately 4000 genes. e. All of the above answers are correct.
c
6. During in vitro DNA replication, which of the following components is not required? a. single-stranded DNA b. a primer containing a 3′-OH c. DNA helicase to separate the strands d. DNA polymerase to catalyze the reaction e. nucleotide precursors
c
6. Why is the lac operon of E. coli important to biotechnology research? a. IPTG is a cheaper additive than lactose to growing cultures. b. The lac operon is not used in biotechnology research. c. The inducers and regulators of the lac operon are used to control the expression of genes in model organisms. d. The lac operon controls the amount of lactose that E. coli metabolizes. e. All of the above.
c
7. What feature about eukaryotic transcription factors is useful to biotechnology research? a. They have two domains, both of which bind to DNA. b. They have two domains, both of which bind to separate proteins. c. They have two domains: one domain binds DNA and the other binds to some part of the transcription apparatus. d. They have only one domain that binds to RNA polymerase. e. They have two domains but neither domain can be engineered and are therefore not useful to biotechnology research.
c
7. Which of the following statements is not correct about the usefulness of fungi in biotechnology research? a. Fungi produce the blue veins in some types of cheeses. b. Yeast is responsible for the alcohol in beer and for bread rising. c. Fungi are called "the workhorses of molecular biology." d. The 2-micron circle is a useful extrachromosomal element from yeast that can be utilized in molecular biology research. e. Fungi produce many industrial chemicals and pharmaceuticals.
c
8. During chemical synthesis of DNA, a portion of the nucleotides does not react. How can the efficiency of such reactions be increased? a. The unreacted nucleosides are not acetylated so that more can be added in subsequent reactions. b. The efficiency of the reaction is not critical. Instead, the quality of the final product is more important than the quantity. c. The desired oligonucleotide can be separated from the truncated oligos by electrophoresis. d. Oligonucleotides should be made using DNA polymerase III instead of in vitro chemical synthesis. e. The reaction times can be increased to allow the reaction to be more efficient.
c
8. Which type of mutation is the most common? a. insertion of one or more bases b. deletion of one of more bases c. base substitutions d. inversion of DNA segments e. duplications of DNA segments
c
9. Which of the following vectors holds the largest pieces of DNA? a. plasmids b. bacteriophage c. YACs d. PACs e. cosmids
c
12. Choose the statement about translation that is not correct. a. The ribosome is comprised of multiple subunits containing both ribosomal RNA and proteins. b. The consensus sequence UAAGGAGG is called the Shine-Dalgarno sequence and is recognized by the ribosome. c. Translation requires three initiation factors, two elongation factors, and two release factors. d. Transcription and translation are coupled in eukaryotes. e. There are three sites (E, P, and A) on the ribosome that can be occupied by a tRNA.
d
12. What is the term used to describe the process of synthesizing oligonucleotides directly on the glass slide? a. photosynthesis b. photolithography c. light-activated oligosynthesis d. on-chip oligosynthesis e. protected oligosynthesis
d
12. What process is used to identify possible ribozyme substrates? a. DNA SELEX b. DNA BLAST c. RISC d. RNA SELEX e. GENEi
d
12. Which of the following statements about degenerate primers is not correct? a. Degenerate primers have a mixture of two or three bases at the wobble position in the codon. b. Because of the nature of degenerate primers, the annealing temperature during PCR using these primers must be lowered to account for the mismatches. c. Degenerate primers are often designed by working backwards from a known amino acid sequence. d. Degenerate primers are used even when the sequence of DNA is known. e. Within a population of degenerate primers, some will bind perfectly, some will bind with mismatches, and others will not bind.
d
13. Why must reverse transcriptase be used to create a eukaryotic expression library? a. Reverse transcriptase is only used to create prokaryotic expression libraries. b. Reverse transcriptase creates cDNA from mRNA in prokaryotes. c. Reverse transcriptase ensures the gene is in the correct orientation within the expression vector to create protein. d. Reverse transcriptase creates cDNA from mRNA because genes in eukaryotes have large numbers of noncoding regions. e. No other enzymes are used to create expression libraries except restriction enzymes.
d
14. Why would a researcher want to use RT-PCR? a. RT-PCR is used to compare two different samples of DNA for relatedness. b. RT-PCR creates an mRNA molecule from a known DNA sequence. c. RT-PCR generates a protein sequence from mRNA. d. RT-PCR generates a DNA molecule without the noncoding introns from eukaryotic mRNA. e. All of the above are applications for RT-PCR.
d
15. How is subtractive hybridization useful? a. To eliminate genes from a gene library. b. To create expression libraries based on genes that are currently being expressed. c. To identify and construct new probes for Southern and Northern hybridizations. d. To identify sets of genes that are only expressed under certain conditions. e. All of the above are useful traits of subtractive hybridization.
d
3. Which of the following statements about eukaryotic DNA packaging is true? a. The process involves DNA gyrase and topoisomerase I. b. All of the DNA in eukaryotes can fit inside of the nucleosome without being packaged. c. Chromatin is only used by prokaryotes and is not necessary for eukaryotic DNA packaging. d. Eukaryotic DNA packaging is a complex of DNA wrapped around proteins called histones, and further coiled into a 30-nanometer fiber. e. Once eukaryotic DNA is packaged, the genes on the DNA can never again be expressed.
d
4. Which of the following statements about mismatch repair is incorrect? a. MutSHL excise the mismatched nucleotides from the DNA. b. Mismatch repair proteins identify a mistake in DNA replication. c. The mismatch proteins recruit DNA polymerase III to synthesize new DNA after the proteins have excised the mismatched nucleotides. d. MutSHL can synthesize new DNA after a mismatch has been excised. e. MutSHL monitors the methylation state of the DNA to determine which strand contains the correct base when there is a mismatch.
d
4. Which of the following statements is not true about mRNA? a. Prokaryotic mRNA may contain multiple structural genes on the same transcript, known as polycistronic mRNA. b. Eukaryotes only transcribe one gene at a time on mRNA, called monocistronic mRNA. c. Eukaryotes are capable of having polycistronic mRNA; however, only the first cistron will be translated. d. Eukaryotes almost always produce polycistronic mRNA. e. The genes for metabolic pathways in bacteria are typically located close together and transcribed on one mRNA.
d
4. Which organism has the most genes? a. H. sapiens b. D. melanogaster c. O. sativa d. P. trichocarpa e. A. thaliana
d
6. Which statement about RNAi is not correct? a. RNAi was first discovered in plants. b. RNAi has two phases: initiation and effector. c. During the initiation phase of RNAi, a protein called Dicer cuts dsRNA into small fragments called siRNAs. d. Non-specific interactions between the antisense siRNA and mRNA often cause mRNAs to be degraded that should not have been. e. The RNA-induced silencing complex has both helicase and endonuclease activities.
d
9. Which of the following statements about eukaryotic mRNA processing is not correct? a. The mRNA transcript must be exported from the nucleus. b. A 5′cap and a 3′poly(A) tail must be added. c. The introns are removed. d. A 3′cap and a 5′poly(A) tail must be added. e. Exons are spliced together to form the mRNA transcript.
d
1. Which of the following are important features for transcription? a. promoter b. RNA polymerase c. 5′and 3′UTRs d. ORF e. all of the above
e
1. Which of the following enzymes aid in uncoiling DNA? a. DNA gyrase b. DNA helicase c. topoisomerase IV d. single-stranded binding protein e. all of the above
e
1. Which of the following is utilized in genomic research? a. microsatellite polymorphism b. restriction fragment length polymorphism c. single nucleotide polymorphism d. variable number tandem repeat e. all of the above
e
1. Which of the following statements about antisense RNA is true? a. Antisense RNA binds to form double-stranded regions on RNA to either block translation or intron splicing. b. Antisense RNA is transcribed using the sense strand of DNA as a template. c. The sequence of antisense RNA is complementary to mRNA. d. Antisense RNA is made naturally in cells and also artificially in the laboratory. e. All of the above statements about antisense RNA are true.
e
10. Identify the statement about multicellular model organisms that is correct. a. C. elegans has been used extensively to study multicellular interactions partly because the creature can reproduce by self-fertilization (genetic clones) or sexually (novel genetic organisms). b. Based on homology, research on Drosophila mutants has identified genes in the human genome responsible for body patterns. c. The zebrafish, or Danio rerio, are used to study developmental genetics because the embryonic cells are easily destroyed or manipulated and the effects can be observed within 24 hours. d. The mouse is a model organism for studying human genetics, physiology, and development because less than 1% of the genes in the mouse genome have no genetic homology in humans. e. All of the statements are correct.
e
11. Condon bias can be overcome by which scenario? a. genetically engineering host organisms to express rarer tRNAs. b. Nothing can be done to overcome codon bias when expressing proteins. c. genetically engineering the gene so that the codons are recognized by more abundant tRNAs. d. Genetically engineer the gene to remove the codons for rare tRNAs. e. Both A and C are suitable scenarios.
e
11. Which of the following is not an advantage of automated cycle sequencing over the chain termination method of sequencing? a. The reactions in an automated sequencer can be performed faster. b. The reactions performed in an automated sequencer can be read by a computer rather than a human. c. Higher temperatures are used during cycle sequencing, which prevent secondary structures from forming in the DNA and early termination of the reaction. d. In cycle sequencing, nonspecific interactions by the primer can be controlled by raising the annealing temperature. e. All of the above are advantages of cycle sequencing.
e
11. Why are gene libraries constructed? a. To find new genes. b. To sequence whole genomes. c. To compare genes to other organisms. d. To create a "bank" of all the genes in an organism. e. All of the above.
e
12. Why is Arabidopsis thaliana used as a model organism for plant genetics and biology? a. Arabidopsis responds to stress and disease similarly to important crop plants such as rice, wheat, and corn. b. Arabidopsis is easy to grow and maintain in the laboratory. c. The genome of Arabidopsis is relatively small compared to other plants. d. The generation cycle of Arabidopsis is shorter than most other crop plants and produces many seeds for further study. e. All of the above statements are reasons for using Arabidopsis as a model organism.
e
13. What property must a ribozyme possess in order to be used in clinical medicine? a. stability and resistance to degradation b. no deleterious side effects to the host c. expression within a diseased cell only d. be able to be delivered to the correct location e. all of the above
e
13. Which of the following statements highlights the issues surrounding oligonucleotide microarrays? a. A duplex may not properly form if the mRNA probe has several mismatches compared to the oligonucleotide sequence. b. The ability to hybridize to the oligonucleotides will be decreased if the probe is able to form a stem-loop structure. c. The A:T content of the oligonucleotide may affect the stability of the duplex. d. Depending on the size of the spacer, incoming probes may not be able to hybridize if the spacer is too small or the oligonucleotide may fold back on itself if the spacer is too long. e. All of the above are issues surrounding oligonucleotide microarrays.
e
13. Which of the following techniques would allow a researcher to determine the genetic relatedness between two samples of DNA? a. inverse PCR b. reverse transcriptase PCR c. TA cloning d. overlap PCR e. randomly amplified polymorphic DNA
e
13. Why are viruses significant to biotechnology? a. They are able to insert their genome into the host genome, thus integrating genes in the process. b. Viruses can be used to alter the genomes of other organisms. c. Reverse transcriptase, an enzyme used in molecular biology, is encoded in a retroviral genome. d. Viruses play an important role in delivering gene therapy to humans. e. All of the above statements are reasons why viruses are significant to biotechnology research.
e
14. What can whole-genome arrays identify? a. regions on the DNA that are methylated b. transcription factor binding sites c. various polymorphisms d. repetitive elements e. all of the above
e
14. Which of the following are common features of expression vectors? a. Small segments of DNA that encode tags for protein purification. b. Transcriptional start and stop sites. c. A tightly controlled promoter than can only be induced under certain circumstances. d. Antibiotic resistance gene. e. All of the above are common features of expression vectors.
e
15. What is an example of an effector molecule for riboswitches? a. some cyclic mononucleotides b. oligonucleotides c. metal ions d. some proteins e. all of the above
e
15. Which of the following elements is important in biotechnology research? a. transposons b. F plasmid c. satellite viruses d. plasmids e. all of the above
e
15. Which of the following is an application for PCR? a. site-directed mutagenesis b. creation of insertions, deletions, and fusions of different gene segments c. amplification of specific segments of DNA d. for cloning into vectors e. all of the above
e
2. Which of the following is important for gel electrophoresis to work? a. Negatively charged nucleic acids to migrate through the gel. b. Ethidium bromide to provide a means to visualize the DNA in the gel. c. Agarose or polyacrylamide to separate the DNA based on size. d. Known molecular weight standards. e. All of the above are important for gel electrophoresis.
e
3. Which of the following is a modification of antisense oligonucleotide structure to increase intracellular stability? a. insertion of an amine into the ribose ring to create a morpholino structure b. attachment of nucleic acid bases to a peptide backbone instead of a sugar-phosphate backbone c. replacement of one of the oxygen atoms in the phosphate group with a sulfur atom to inhibit nuclease degradation in some molecules d. addition of an O-alkyl group to the 2′-OH of the ribose group to make the molecule resistant to nuclease degradation e. all of the above
e
4. Which of the following is an appropriate method for detecting nucleic acids? a. Measuring absorbance at 260 nm. b. Autoradiography of radiolabeled nucleic acids. c. Chemiluminescence of DNA labeled with biotin or digoxigenin. d. Measuring the light emitted after excitation by fluorescent-labeled nucleic acids on a photodetector. e. All of the above are appropriate methods for detecting nucleic acids.
e
4. Which statement about Thermus aquaticus is false? a. T. aquaticus was isolated from a hot spring. b. The DNA polymerase from T. aquaticus is used in molecular biology for a procedure called polymerase chain reaction (PCR). c. The DNA polymerase from T. aquaticus is able to withstand very high temperatures. d. T. aquaticus can survive high temperatures and low pH. e. T. aquaticus is found in the frozen lakes of Antarctica.
e
5. In what way is eukaryotic transcription more complex than prokaryotic transcription? a. Eukaryotes have three different RNA polymerases, whereas prokaryotes only have one RNA polymerase. b. Eukaryotic transcription initiation is much more complex than prokaryotic initiation because of the various transcription factors involved. c. Upstream elements are required for efficient transcription in eukaryotic cells, but these elements are not usually necessary in prokaryotes. d. Eukaryotic mRNA is made in the nucleus. e. All of the above statements outline ways that eukaryotic transcription is more complex.
e
5. What is a gene? a. a segment of DNA that encodes a protein b. a segment of DNA that encodes nontranslated RNA c. sequences of DNA that are not transcribed d. a segment of DNA that is transcribed e. all of the above
e
5. Which of the following terms describes when gene regulation occurs by short is dsRNA molecules triggering an enzymatic reaction that degrades the mRNA of a target gene? a. post-transcriptional gene silencing b. quelling c. co-suppression d. RNA interference e. all of the above
e
6. Plasmids from bacteria can be described by which of the following statements? a. Plasmids provide an advantage to the host bacterium to compete against non-plasmid-containing bacteria for nutrients. b. Plasmids are used as a molecular biology tool to express other genes efficiently in the host bacterium. c. Plasmids are extrachromosomal segments of DNA that carry several genes beneficial to the host organism. d. Plasmids have their own origin of replication. e. All of the above statements describe plasmids.
e
8. How can RNAi be triggered in mammalian cells? a. transfection of siRNA b. chemically synthesized siRNA c. degradation of target mRNA through shRNA creation d. modification of an existing shRNA to recognize a different mRNA e. all of the above
e
8. Which of the following DNA structure modifications are used to regulate transcription? a. acetylation/Deacetylation of the histone tails b. methylation of specific bases in the DNA sequence c. imprinting, such as X-inactivation d. chromatin condensation e. All of the above are important modifications for transcription regulation
e
8. Which of the following are useful traits of cloning vectors? a. An antibiotic resistance gene on the plasmid for selection of cells containing the plasmid. b. A site that contains unique, clustered restriction enzyme sequences for cloning foreign DNA. c. A high copy number plasmid so that large amounts of DNA can be obtained. d. Alpha complementation to determine if the foreign DNA was inserted into the cloning site. e. All of the above are useful traits.
e
9. Which of the following yeast cellular component is typically not found in bacteria? a. centromeres b. telomeres c. nuclear pores d. nuclear envelope e. All of the above are found in yeast and not bacteria.
e
