MCB2010 FINAL EXAM 2025

The bacterial chromosome is: - -Both circular and found in a nucleus Which of the following types of plasmids facilitates the transfer of genetic material among bacteria? - -fertility plasmids Which of the following is true about bacterial plasmids? - -they are small circular DNA molecules that can replicate autonomously Which of the following is involved in translation? - -mRNA, rRNA, and tRNA are all involved Typical eukaryotic genomes are compared of _________ DNA molecules - -multiple linear The AUG codon functions in coding for the AA methionine and as the: - -start signal (codon) semiconservative DNA replication means that - -each daughter DNA molecule is composed of one original strand and one new strand Which of the following processes is involved in the 'central dogma' of genetics? - transcription and translation Which of the following are considered to be frameshift mutations? - -insertions and deletions Which of the following causes mutations by creating thymine dimers? - -ultraviolet light The horizontal transfer process known as transduction... - -involves a virus Bacteria acquire new DNA from the environment in the process of: - -transformation in conjugation, F+ cells: - -contain a plasmid DNA sequences known as transposons contain: - -F+ plasmids codons are recognized by - -tRNA The process of DNA replication is described as: - -semi-conservative MCB2010 MCB2010 MCB2010 Physical removal of microbes without killing them is __________ - -degerming Which of the following is true regarding disinfectants? - -they are used only on inmate objects/surfaces Which of the following is an example of sanitization? - -a public toilet treated with disinfectants an antimicrobial agent that ___________ ______ will have the most lasting germicidal effect. - -damaged DNA Which of the following is a bacteriostatic? - -freezing below 0°C antimicrobial agents that damage nucleic acids also affect - -protein synthesis Which of the following is used for microbial control in fresh fruits and vegetables? - gamma rays Air can be disinfected using - -both HEPA filters and ultraviolet light What category of chemical control agent is in silvadene? - -heavy metals The use of lysozyme during the preparation of cheeses and wines is effective in reducing the numbers of - -bacteria The heavy metal compound ________ is used as a preservative in some vaccines. - thimerosal Disinfecting agents naturally produced by microorganisms are ______________. - antimicrobials Honey can be stored at room temperature for long periods of time because it is: - hypertonic What factors needs to be considered when choosing a method of microbial control? - - the site to be treated -environment -susceptibility of the microbes Broad spectrum synthetic antimicrobials were discovered by - -Gerhard Domagk Which of the following procedures is currently the standard test used in the U.S. for evaluating the efficacy of antiseptics and disinfectants? - -use-dilution test an antimicrobial that inhibits cell wall synthesis will result in which of the following? - cells become more susceptible to osmotic pressure MCB2010 MCB2010 Beta-lactam antibiotics have an effect on which of the following types of cells? - bacterial cells Which of the following is a primary advantage of semisynthetic drugs? - -they have a broader spectrum of action a med which specifically targets cell walls that contain arabinogalactan-mycolic acid is: - -isoniazid Which type of antimicrobial agent has the narrowest spectrum of action? - -antivirals The first synthetic antimicrobial widely available for treatment of infections - -was an attachment antagonist meds that should never be prescribed to pregnant women include: - -sulfonamides and tetracyclines A compound is extracted from a microbial culture and is modified in the lab for use as an oral med. this product would be a - -semisynthetic antimicrobial most drugs that inhibit the synthesis of the cell wall act by - -preventing cross linkage of NAM subunits Inhibitors of DNA synthesis specifically effective of prokaryotes are - -quinolones The E-test determines what? - -both susceptibility and MIC (minimum inhibitory concentration) How does resistance to drugs spread in bacterial populations? - -Both horizontal gene transfer and the growth of biofilms spread drug resistance what is the MOA of vancomycin? - -inhibits cell wall synthesis what is the MOA of erythromycin? - -inhibits protein synthesis Drug resistant populations of microbes arise - -When exposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells. What enzyme do human tears have? What does it do? - -lysozyme; destroys peptidoglycan layer Which test to measure the effectiveness of disinfectants and antiseptics reveals the minimum time required for the disinfectant to be effective? - -Kelsey-sykes capacity test Subunits for prokaryotic ribosome: - -50S and 30S MCB2010 Subunits for eukaryotic ribosome: - -60S and 40S Which of the following microbial methods does not actually kill microbes or inhibit their growth but instead removes them physically from samples? - -filtration How does the addition of salt or sugar help preserve food? - -creates a hypertonic environment T/F: UV does not penetrate well - -true The effectiveness of chemical disinfectants has historically been compared to that of which of the following? - -phenol Parameters for flash pasteurization: - -72 degrees C for 15 seconds What are the three stop codons? - -UAA, UAG,