MIBO EXAM 2 PRACTICE (PT. 1) WITH COMPLETE SOLUTIONS.

_______ use an internal RNA primer so that the end of the eukaryotic chromosome can be replicated. a. Primases b. RNA polymerases c. Telomerases d. DNA polymerases e. Helicases c. Telomerases A transmembrane sensor kinase protein senses an environmental condition outside __________ bacteria or in the periplasm of a/an __________ bacteria. a. Gram-positive; Gram-negative b. Gram-negative; Gram-positive c. prokaryotic; eukaryotic d. prokaryotic; archaean e. Gram-positive; acid-fast a. Gram-positive; Gram-negative In a gel shift assay, a DNA binding protein is mixed with radioactively labelled oligos of a specific sequence. If the protein binds to the DNA sequence, the mobility of the DNA shifts, as measured by gel electrophoresis followed by detection of radiolabel. A critical control in these assays is the addition of cold (non-radioactive) oligos of the same sequence. As increasing amounts of cold oligo are added, what would you expect to happen in this control? a. An intermediate sized band will for d. As more cold oligo is added, the DNA will shift back down to the unbound size. Which of the following is NOT a palindrome? (Ignore punctuation). a. a man, a plan, a canal, panama. b. never odd or even. c. May a moody baby doom a yam? d. Madam, in Eden I'm Adam. e. Murder for a jar of red jam. e. Murder for a jar of red jam. Based on what you know about regulation, which would be more likely to be ubiquinated? a. An RNA polymerase subunit. b. An activator. c. A histone. d. A cytoskeleton protein. e. All are equally likely. b. An activator. Which molecule is responsible for removing torsional stress during DNA replication? a. DNA primase b. single-stranded binding protein c. RNase H d. DNA gyrase e. DNA ligase d. DNA gyrase The process of plasmid addiction is based on genes that code for: a. short-lived toxin and short-lived antidote b. long-lived toxin and long-lived antidote c. long-lived toxin and short-lived antidote d. short-lived toxin and long-lived antidote e. high plasmid copy number c. long-lived toxin and short-lived antidote F factor contains how many origins of replication? a. one b. two c. three d. four e. none b. two Newly replicated, and consequently __________, DNA sequences are invisible to a restriction enzyme. a. mutated b. restricted c. modified d. hemimethylated e. single-stranded d. hemimethylated The ________ is not transcribed and the _________ is not translated. a. template strand; coding strand. b. start codon; stop codon. c. untranslated leader; untranslated trailer. d. transcription start site; transcription terminator. e. promoter region; Shine-Dalgarno box. e. promoter region; Shine-Dalgarno box. What to sigma factors, DNA B, and tRNAs charged with methionine have in common. a. Nothing. b. All are involved in initiation. c. All are involved in elongation. d. All are involved in termination. e. All have RNA subunits. b. All are involved in initiation. _________ RNA polymerase plus sigma factor together are called __________. a. Transcription; translation b. Translation; transcription c. Ribosome; rRNA d. Holoenzyme; core e. Core; holoenzyme e. Core; holoenzyme Microarrays are rapidly being replaced by: a. Northern blots. b. Sanger sequencing. c. RNAseq. d. Bioinformatics. e. PCR. c. RNAseq. What type of bond does DNA polymerase form? a. aminoacyl bonds b. peptide bonds c. phosphodiester bonds d. hydrogen bonds e. disulfide bonds c. phosphodiester bonds The thermal stability of the helix is predominantly due to the __________ of the hydrophobic base pairs. a. stacking b. binding c. repulsion d. attraction e. transformation a. stacking A derivative F plasmid that contains host DNA is called an: a. F plasmid b. F+ plasmid c. F- plasmid d. F' plasmid e. Hfr plasmid d. F' plasmid The semiconservative mechanism of replication provides for each daughter duplex to be checked for __________, based on its parent strand. a. pseudogenes b. introns c. plasmids d. redundancy e. accuracy e. accuracy Bacteria is to archaea as sigma 70 is to: a. Rho b. TFIID c. Lambda d. Ef-Tu e. IF3 b. TFIID A ligand binds to a protein bound to DNA, and the protein leaves the DNA. The protein was most likely a: a. Activator. b. Repressor. c. Sensor kinase. d. Response regulator. e. Enhancer. b. Repressor. A nucleoid gently released from E. coli appears as 30-100 tightly wound loops, each defined by anchoring proteins called: a. histones b. histone-like proteins c. supercoils d. gyrase e. topoisomerase b. histone-like proteins Which of the following is NOT true about histones? a. They are rich in arginine and lysine. b. They are positively charged. c. They are acidic proteins. d. They bind to negatively charged DNA. e. They form units with DNA called nucleosomes. c. They are acidic proteins. Which of the following terms refers to gene duplications that have decayed into nonfunctional entities? a. introns b. contigs c. orthologs d. pseudogenes e. Okazaki fragments d. pseudogenes Which of the following is evidence of gene reduction? a. altered GC content b. different codon usage c. pseudogenes d. all of the above e. none of the above c. pseudogenes The smallest cellular genomes identified thus far are those of __________. a. E. coli b. Staphylococcus c. Streptococcus d. Mycoplasma e. yeast d. Mycoplasma Which of the following is NOT true of DNA replication in E. coli? a. It is conservative. b. It is bidirectional. c. The second strand is synthesized discontinuously. d. DnaA triggers initiation. e. Synthesis occurs in the 5'-to-3' direction. a. It is conservative. DNA and RNA polymerase both use a ________ in catalysis because it ________. a. serine residue; stabilizes the phospodiester backbone. b. cytochrome subunit; stabilizes the phospodiester backbone. c. covalently bound adenine; forms an ester linkage with the amino end. d. magnesium ion; stabilizes the phosphate groups in nucleotide triphosphates. e. lysine residue; hydrogen bonds with base pairs. d. magnesium ion; stabilizes the phosphate groups in nucleotide triphosphates. Clostridium phylofermentans converts cellulose into primarily: a. Acetone. b. Acetate. c. Ethanol. d. Glucose. e. Arabinose. c. Ethanol. Which drug interferes with transcription in prokaryotes? a. chloramphenicol b. erythromycin c. rifamycin B d. streptomycin e. tetracycline c. rifamycin B Some microbes use gene regulation to periodically change their appearance in a process called __________. a. sporulation b. attenuation c. regulation d. activation e. phase variation e. phase variation 1.::__________ prevent transcription, whereas __________ stimulate transcription. a. Activators; repressors b. Inducers; corepressors c. Corepressors; inducers d. Regulators; repressors e. Repressors; activators e. Repressors; activators When the chromosome replicates, how is the newly made strand related to its template strand? a. The two strands have identical sequences and are parallel to each other. b. The two strands have complementary sequences and are parallel to each other. c. The two strands have identical sequences and are antiparallel to each other. d. The two strands have complementary sequences and are antiparallel to each other. e. The two strands have identical sequences and are antiparallel to each othe d. The two strands have complementary sequences and are antiparallel to each other. Salmonella can conduct interspecies __________ with E. coli. a. transduction b. transformation c. transposition d. conjugation e. recombination d. conjugation Which of the following genes belongs to the so-called flexible gene pool? a. ribosome b. cell envelope c. antibiotic resistance d. DNA replication e. metabolic pathways c. antibiotic resistance Initiation of DNA replication is controlled by DNA __________ and by the binding of a specific initiator protein to the origin sequence. a. methylation b. ligase c. helicase d. restriction e. gyrase a. methylation _________ is the process of moving a transposable element within or between DNA molecules. a. Transposition b. Transduction c. Transformation d. Conjugation e. Reversion a. Transposition _________ RNAs bind to complementary sequences of target transcripts and stimulate or prevent translation. a. Ribosomal b. Transfer c. Messenger d. Antisense e. Small d. Antisense A special sigma factor, __________, is used to transcribe genes encoding the translocasome necessary for cell competency. a. SigH b. Sig70 c. SigT d. SigC e. Sig20 a. SigH When a gene sequence is shown, only one strand is shown and it is always listed in the 5' to 3' direction. The sequence of which DNA strand is shown? a. The coding strand. b. The template strand. c. The transcript strand. d. The Kozak strand. e. The anticodon strand. a. The coding strand. The 5'-end of the nicked strand of F factor moves through a pore in the conjugation complex by a process driven by __________, which synthesizes a replacement strand in the donor cell using the intact strand as template. a. DNA pol I b. DNA pol II c. DNA pol III d. ligase e. Hfr c. DNA pol III Which of the following bacteria requires artificial assistance to become competent to take up DNA? a. Bacillus b. E. coli c. Haemophilus d. Neisseria e. Streptococcus b. E. coli Arthur Kornberg won a Nobel Prize for painstaking biochemical purification of DNA polymerase by sequentially fractionating cell extracts using different types of purification until he was left with a single protein that was capable of synthesizing DNA. His efforts laid the groundwork for much of the protein biochemistry to follow, but it was soon revealed that he had purified DNA polymerase I. He was hoping to purify the enzyme that replicates the genome. What enzyme was he probably attempting t b. DNA pol III How does the squid Euprymna scolopes, the Hawaiian Bobtail squid, control its bioluminescence? a. By inducing transcription of the luciferase protein. b. By producing homoserine lactones. c. By producing an antibiotic that kills resident bacteria. d. By releasing a burst of oxygen, necessary for the oxidation of FMNH2 by luciferase. e. By pumping most bacteria out of its light organ every morning. e. By pumping most bacteria out of its light organ every morning.