MCB 2004C Module-2-Practice-Exam-Answer-Key- University of Central Florida

MCB 2004C Module-2-Practice-Exam-Answer-Key- University of Central Florida What is the function of the Z ring in binary fission? A. It forms a contractile ring at the septum = Made up of FtsZ (tubulin homologues) molecules important for bacterial septation B. It controls the replication of DNA = Replisome contains DNA replication machinery C. It separates the newly synthesized DNA molecules = ParA polymerizes/depolymerizes to attach to ParB which recognizes the DNA Sequence parS which is next to the origin of replication D. Both A and B E. Both B and C 2. Which of the following was the first broad-spectrum antibiotic discovered? A. Salvarsan = First Synthetic antibiotic B. Chloramphenicol = Made by a bacterium C. Penicillin = First True antibiotic D. Oxazolidinone = Considered new “drug of last resort” E. Vancomycin 3. Which of the following is true about biofilms? (select all that apply) A. Only bacteria of similar strains can form biofilms = Composed of many different microorganisms B. Heterogeneity among the bacteria can lead to increased interactions and communication = Microbes with varying diversity communicate heavily in biofilms via quorum sensing C. Microbes that grow attached to the surfaces of these biofilms are planktonic = They are sessile, think plankton are planktonic; they are freely floating D. The most metabolically active cells are located at the base of the biofilm = Slow growers near the base of the biofilm (Ch. 7 slide 35) not as metabolically active but still active E. They often have an EPS which provides structural and functional support = Extracellular polymeric substance makes biofilms tough to remove Ex. Biofilms on surface of teeth can cause damage in the form of cavities and tooth decay; have to scrape it off in a dental procedure. Conventional cleaning agents and antibiotics can’t get past the EPS barrier. 4. Which of the following is true in relation to the central dogma of biology? A. DNA is the template for its own replication = Depends on the holoenzyme DNA polymerase B. The flow of genetic information goes from DNA to RNA to proteins C. mRNA is the template for protein translation D. Both A and C E. All of the above = (Ch. 13 slide 2) 5. In regard to proteins: = Made up of single or multiple polypeptides, contain covalent and non-covalent bonds A. Denaturing results in the loss of secondary structures = Denaturing results in a protein losing all its structures except their primary structure; Ex. increasing temperature or altering pH B. They grow from the N-terminus to the C-terminus = Starts from the North/ Nterminus (where cleavage also takes place with signal peptides in order to activate proteins) C. All proteins can have a quaternary structure D. Both A and B E. Both B and C 6. Which of the following is false regarding bacterial horizontal gene transfer? A. Bacterial transformation requires bacteria to be competent = DNA taken up from environment B. Bacterial conjugation requires a form of cell-cell contact to take place, usually through a sex pilus = Sex pilus for conjugation NOT T4P (type IV pilus); Sex pilus can transfer R plasmid C. It can involve the transfer of genetic material from parent to offspring = This is vertical gene transfer D. Bacterial transduction involves phages inserting into the host’s genome E. All of the above are true 7. Which of the following is false regarding penicillin? A. It can activate autolysins = Breaks bonds in peptidoglycan which allows for easy passage for NAM and NAG + new addition of them and assists with cellular growth (Needs to be heavily regulated). Penicillins can further activate these to lyse the bacterial cell B. Organisms that produce β-lactamase can become resistant to penicillin = Penicillinase C. Penicillin V and G are narrow spectrum and only work on Gram-positives = Ampicillin is semi-synthetic and has a broader spectrum than V and G D. It is responsible for blocking peptide elongation = Deals with protein synthesis inhibition not involved with penicillin (cell wall inhibitor) E. It is a true antibiotic that is made by a fungus = Penicillium (fungi) 8. Which of the following is true? A. Most microbes are able to maintain their internal temperature = Can maintain internal pH near neutrality. Also, cardinal growth temperatures; Minimum (no growth), Optimum (Max growth) and maximum (no growth), unique to different microbes B. Hfr cells have integrated F factors while F+ cells do not = Hfr has an integrated F factor in its DNA, it donates a partial copy of its plasmid with DNA, receiving bacteria stays F-. F+ bacteria do not have an integrated F factor, thus, can donate a whole plasmid making receiving cell F+. C. Natural selection typically is seen during the death phase of microbial growth = Long-term stationary: Bacteria continually evolve, and some can develop mutations in order to be fit for the changing environment D. The Ames test is used to test the carcinogenic ability of bacteria = Can’t test for carcinogens, unicellular organism E. Trimethoprim is a true antibiotic that functions as an antimetabolite = Synthetic antibiotic, can be used in conjunction with sulfa drugs; synergism 9. Clostridium botulinum divides every 35 minutes. If the starting population is 5 cells, how many bacteria would you have after 3.5 hours? . . . . . . .