Bacteriology Final Exam Questions and Answers, Exams of Nursing

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Bacteriology Final Exam questions with complete solutions T/F: Bacterial cells usually contain one circular chromosome - correct answer ✔✔True T/F: Bacterial cells are usually slightly larger than eukaryotic cells - correct answer ✔✔False T/F: Viruses are considered living things by most biologists - correct answer ✔✔False T/F: All species of bacteria cause disease - correct answer ✔✔False T/F: Electron microscopes provide higher magnification and better resolution than light microscopes - correct answer ✔✔True T/F: A bacillus is a rod-shaped bacterium - correct answer ✔✔True T/F: Gram positive cells appear red, pink, or orange after a successful Gram stain - correct answer ✔✔False T/F: The cell wall in bacteria is selectively permeable - correct answer ✔✔False T/F: Obligate aerobes require plentiful oxygen gas (O2) - correct answer ✔✔True T/F: Mesophiles grow best at a temperature above 70°C - correct answer ✔✔False T/F: All disinfectants are bactericidal - correct answer ✔✔False T/F: Boiling contaminated water does NOT always destroy endospores - correct answer ✔✔True T/F: 100% ethanol is more effective than 70% ethanol at destroying microbes - correct answer ✔✔False T/F: The antibiotics streptomycin and tetracycline are produced by a type of mold - correct answer ✔✔False T/F: HEPA filters remove bacteria from air - correct answer ✔✔True T/F: Autoclaving always destroys prions - correct answer ✔✔False T/F: All anabolic pathways are biosynthetic and endergonic - correct answer ✔✔True T/F: Fermentation is an example of an anabolic pathway - correct answer ✔✔False T/F: ADP contains two phosphate groups - correct answer ✔✔True T/F: Enzymes speed up biochemical reactions by decreasing the activation energy required to start a reaction - correct answer ✔✔True T/F: Aerobic respiration produces less ATP per glucose than fermentation - correct answer ✔✔False T/F: Cyanobacteria are the closest living prokaryotic relatives to algae and plants - correct answer ✔✔True T/F: There are three domains of living things - correct answer ✔✔True T/F: Bacteria and archaea are in separate domains - correct answer ✔✔True T/F: Bergey's Manual of Determinative Bacteriology is the authoritative guide for classifying prokaryotes - correct answer ✔✔False Bacteria accumulate excess water by osmosis when placed in a hypotonic fluid like pure water. They do not normally burst under these conditions because a counter-pressure is applied by the - correct answer ✔✔cell wall Cell rupture due to osmotic pressure is called - correct answer ✔✔osmotic lysis Peptidoglycans consists of long polysaccharide chains reinforced by short chains of - correct answer ✔✔amino acids An "outer membrane" consisting of one half phospholipid and one half lipopolysaccharide is present in - correct answer ✔✔Gram negative bacteria Whats TRUE about Gram positive bacteria - correct answer ✔✔their cell walls contain teichoic acid Endotoxins are molecules produced by some bacteria that trigger strong immune responses in humans, including fever. Whats an example of an endotoxin - correct answer ✔✔lipopolysaccharide The capsule is the outermost protective layer of the cell envelope in prokaryotic cells. A capsule is also called a - correct answer ✔✔glycocalyx What is NOT TRUE about the prokaryotic DNA molecules known as "plasmids" - correct answer ✔✔they are linear Ribosomes are the sites of - correct answer ✔✔protein synthesis Flagella are used for - correct answer ✔✔locomotion Endospores are produced by - correct answer ✔✔some Gram positive bacteria A certain species of bacteria has a generation time of 20 min. If the initial population consists of 30 cells, how many cells would be present after 1 hour, assuming ideal conditions for growth - correct answer ✔✔240 A ______ consists of a complex, natural community of bacteria encased within an extracellular polymeric material. Such communities grow on wet rocks, teeth, pipes, toliet bowls, and other surfaces - correct answer ✔✔biofilm Bacteria that obtain energy from sunlight and carbon atoms from atmospheric CO2 are called - correct answer ✔✔photoautotrophs Limiting nutrients are those available in the environment in the smallest amounts relative to need. How fast an organism is capable of growing is thus often limited by the availability of these nutrients. For each bacteria in a natural environment, which os the following is the most limiting nutrient - correct answer ✔✔phosphorus Prokaryotes that prefer environments with high salt levels - correct answer ✔✔halophiles Prokaryotes that prefer environments with high temp - correct answer ✔✔thermophiles Species of bacteria capable of producing endospores are most likely to begin producing endospores during which stage of growth - correct answer ✔✔stationary phase Colony-forming units are determined by a - correct answer ✔✔standard plate count Chocolate agar contains - correct answer ✔✔lysed red blood cells what combination results in a 50-fold dilution - correct answer ✔✔1 part original sample and 49 parts diluent Hemolytic bacteria - correct answer ✔✔produce a toxin which destroys red blood cells the risks of bacterial combination and infection are minimized by using the proper - correct answer ✔✔aseptic technique Who pioneered the use of an antiseptic during surgery - correct answer ✔✔Joseph Lister 70% ethanol does NOT destroy - correct answer ✔✔naked viruses Pasteurization involves heating a fluid at high temps for - correct answer ✔✔a few seconds Bleach has antimicrobial properties due to the presence of - correct answer ✔✔chlorine Heavy metals like mercury and copper damage proteins by interacting with - correct answer ✔✔-SH groups on the amino acid cystenine Hexylresorcionol, hexachlorophene, and triclosan are sometimes added to consumer products for their antimicrobial effects. These substances are classified as - correct answer ✔✔phenolics Vancomycin is sometimes called the antibiotic of last resort. The effect of vancomycin on bacterial cells is - correct answer ✔✔inhibits peptidoglycan synthesis The therapeutic index for a drug is - correct answer ✔✔toxic dose/ therapeutic dose Compared to penicillin, vancomycin has a therapeutic index that is - correct answer ✔✔smaller most common method for sterilizing lab glassware and microbial media - correct answer ✔✔autoclaving A hydrogen ion is equivalent to a - correct answer ✔✔proton NAD+, NADP+, and FAD each carry - correct answer ✔✔two electrons Electronegativity is a measure of an atom or molecules attraction for electrons. What has the lowest electronegativity - correct answer ✔✔glucose When plants, algae, and cyanobacteria perform photosynthesis, what molecule is generated as a by- product - correct answer ✔✔O2 In 1928 Fredrick Griffith first demonstrated - correct answer ✔✔bacterial transformation The E. Coli chromosome contains how many total genes - correct answer ✔✔4,300 What is NOT a type of DNA molecule - correct answer ✔✔ribosomes Modern phylogenetics is based mainly on - correct answer ✔✔nucleic acid sequence data Orders are subdivided into families and families are subdivided into - correct answer ✔✔genera To which genus does halobacterium salinarum belong - correct answer ✔✔Halobacterium Strains are a level of classification - correct answer ✔✔below species The genetic code is degenerate. This means - correct answer ✔✔most amino acids are specified by multiple codons Which type of genetic mutation introduces a premature STOP codon and therefore a truncated protein - correct answer ✔✔nonsense mutation By which process is DNA converted into mRNA - correct answer ✔✔transcription Which mutagen induces point mutations by removing amino groups from nucleotide bases - correct answer ✔✔nitrous acid The Ames test is an indirect selection method used to identify - correct answer ✔✔carcinogens Bacteria carrying plasmids that confer resistance to an antibiotic may be selected from bacteria not carrying plasmids by - correct answer ✔✔growing the bacteria on an agar plate supplemented with the appropriate antibiotic The direct transfer of genetic material from one prokaryotic cell to another is called - correct answer ✔✔conjugation The transfer of genetic material between bacteria by generalized transduction requires - correct answer ✔✔a bacteriophage The uptake of "naked" DNA fragments from the environment by bacteria is called - correct answer ✔✔transformation Bacterial conjugation requires - correct answer ✔✔a sex pillus Which type of horizontal gene flow always involves transfer of all or some of a lineraized plasmid - correct answer ✔✔conjugation After conjugation occurs between F+ and F- cells - correct answer ✔✔the F- cell always becomes F+ The recipient cell requires only a portion of the F plasmid during conjugation between - correct answer ✔✔an Hfr and F- cell Auxotrophs may be identified and isolated by performing - correct answer ✔✔indirect selection R plasmids most often carry genes for - correct answer ✔✔antibiotic resistance Morphology refers to - correct answer ✔✔size and shape The presence of flagella on a bacterium may be determined by performing - correct answer ✔✔a motility test The presence of a black precipitate in an agar tube supplemented with iron indicates - correct answer ✔✔the production of H2S gas What test requires the use of a pH indicator and Durham tubes - correct answer ✔✔a test for sugar fermentation Which test, when positive, results in the formation of O2 bubbles - correct answer ✔✔catalase production in a typical immunological test performed to identify an unknown bacterium, a positive result is indicated by - correct answer ✔✔agglutination Susceptibility of a bacterium to a bacteriophage is indicated by - correct answer ✔✔plaques A spectrophotometer may be used to - correct answer ✔✔extrapolate the G+C content of a bacterial genome When stained with a Gram stain, Gram negative bacteria appear - correct answer ✔✔red A typical prokaryotic cell is - correct answer ✔✔1-10micrometers The most reliable and definitive method for identifying an unknown species of bacteria is - correct answer ✔✔a nucleic acid sequence analysis Genes are located on - correct answer ✔✔chromosomes, plasmids, and transposons Methanogens - correct answer ✔✔produce methane as a by-product Desulfovibrio vulgaris uses elemental sulfur as a final electron acceptor. Therefore, it produces _________ as a by-product - correct answer ✔✔H2S