Exam 2 - Exam ll MICR 2123 — Introductory Microbiology...

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Unformatted text preview: Exam ll MICR 2123 — Introductory Microbiology October 7, 2011 Read all directions completely and carefully. Name g, H Multiple Choice: Circle the letter of the one most correct answer. (2.5 pts. each) 1. Conjugation, transformation or transduction differ from reproduction because they: I f) A) Replicate DNA ‘3 B Transfer DNA vertically, to the next generation of cells. ( 5" W Transfer DNA horizontally, to cells in the same generation. D) Transcribe DNA to RNA 2. Which form of control is the least likely to be reversible and causes the most drastic change? @Altering the DNA sequence C) Translational control B) Transcriptional control D) Posttranslational control 3. When the chromosome replicates, how is a newly made strand related to its template strand? A) The two strands have identical sequences and are parallel to each other. B ‘e two strands have complementary sequences and are parallel to each other. The two strands have identical sequences and are antiparallel to each other. A replication requires which of the following? A i rimer C) ribosome romoter D) mRNA .(fiithout the sigma factor, the core RNA polymerafi, ' ‘ Binds and releases DNA randomly a inds to DNA and pauses B) Transcribes the DNA into RNA ) Makes primers for DNA replication 6. Which of the following is NOT part of initiation of transcription? A) The RNA polymerase holoenzyme B) Binding of the RNA polymerase to the promoter :0)“ Rho protein ‘ Melting of the helix 7. What does it mean to say that the genetic code is degenerate? A) There is more than one kind of amino acid in proteins B) More than one rRNA can bind to the ribosome at the same time [9) A codon is composed of more than one nucleotide. {4D} More than one codon can specify the same amino acid. 8. Peptide bond formation effectively transfers the peptide from the tRNA in the to tRNA in the (Z? P—site;‘A-site C) E-site; A—site WA—site; P—site D) E-site; P-site 9. What is the correct order of the steps in a cycle of PCR? A) Annealing, denaturation, extension B) Denaturation, extension, annealing C Extension, annealing, denaturation {D Denaturation, annealing, extension 10. Specialized transduction differs from generalized transduction in that specialized transduction: A) Kills the host. B, Transfers DNA from one cell to another. Transfers specific DNA sequences. «m D) Involves lysogeny. Exam || Read a“ dl 11. ,A y is recombination advantageous? (a) it gives the ability to enhance the competitive fitness of the cell. B) it allows for faster cell mobility. C) it provides for 3’-> 5’ DNA replication D) it confers the ability to die faster October 7, 2011 -—< f? ' it"sfi‘fiifiw—n i, ; Mic; 12. Assume you have discovered a cell that produces a lipase that works in cold water for a laundry additive. You can increase the efficiency of this enzyme by mutating (changing) one amino acid. This is a: A) Missense mutation Frameshift mutation C) Nonsense mutation D) Silent mutation 13. Binding of tryptophan to the makes a hoiorepressor? Aporepressor C) Repressor B) Corepressor D) inducer 14. Binding of allolactose to Lacl results in: A)—5Lacl inducing transcription Lacl falling off to allow transcription initiation cl falling off and causing repression of transcription Lacl binding RNA polymerase to activate transcription 15. Bacillus anthrax grown in rich media and then quickly shifted to starvation undergoes what is called which is controlled by ? h v A) phase variation; DNA rearrangement sporulation; an alternative sigma factor B) induction; an activator protein D) the heat shock response; DNA rearrangement 16. Some microbes, especially pathogens, use gene regulation to periodically change their appearance in a process that is called , which can allow them to escape a host’s immune response. A) sporulation C regulation B) attenuation jphase variation 17. requires the accumulation of a secreted small molecule called an autoinducer. Quorum-sensing C) Sporulation B) Phase variation D) Replication 18. naturally function to cut the DNA of invading plasmids and phages at specific points. .9, . l A) Methyiases Polymerases B) Gyrases @Restriction endonucleases 19. Replication begins at a single A) promoter; stem-loop ‘ site and ends at a site. :ori; stem loop QM: ter D) promoter; stop codon 20. / hat kind of mutation is pr duced by transposable elements? A) inversion C insertion B) deletion D) substitution Exam ll MICR 2123 — Introductory Microbiology October 7, 2011 Fill in the Blank: (points given for each) Read all directions completely and carefully. Name 21. DNA polymerase is -dependent and synthesizes DNA in the 5! . strand is synthesized d ECG“ "Hm (All? , while the leading strand is synthesized x \ . 1:2. i4} 4 I f U is the process in which bacteriophage carry host DNA from one cell to another . w ., is the process of transferring DNA into another cell but requires termination uses a stem-loop structure to end for transcription. This stem loop structure is similar to that .3/’ used in trp 'f‘: , where the lack of Trp results in the formation of Wmny stem loops) and I) « (yfytwnslation of the trp structural genes whil 5r} the presence of Trp (yes/n0) translation of the trp results in the formation of 1' (how many stem loops) and W5 7—'— » structural genes (14 pts). 27. Define the mode of action for the following antibiotics (10 pts): Streptomycin Tetracycline Chloramphenical Erythromycin ...
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Exam 2 - Exam ll MICR 2123 — Introductory Microbiology...

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