Microbiology Final Mastering 12/08/2012 – Flashcards

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Robert Hooke's observation of the individual units in thin layers of cork tissue led to the development of __________ theory.
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cell
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Lister knew that carbolic acid (phenol) kills bacteria. He used it as the first __________.
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disinfectant
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The protection from disease provided by vaccination is called __________.
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immunity
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The __________ are unicellular, eukaryotic microbes that move by pseudopods, flagella, or cilia.
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protozoa
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__________ involves the ability afforded by genetic engineering to insert a missing gene or replace a defective gene in a human cell.
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Gene therapy
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Microbes are responsible for: synthesis of vitamins breaking down wastes synthesis of acetone and alcohol oxygen generation via photosynthesis All of the above
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All
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An exposure to ________ protects against infection with smallpox.
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cowpox
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All life can be classified into three domains ________.
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Bacteria, Archaea, Eukarya
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Which of the following properties are true of both bacteria and viruses? Both have cell walls composed of peptidoglycan. Both can replicate independently. Both contain DNA and RNA. Both are surrounded by a protein coat. Both use a molecule of nucleic acid to determine heredity.
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Both use a molecule of nucleic acid to determine heredity.
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Mad cow disease is caused by a prion, which is an infectious ________.
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protein
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Which of the following is a scientific name?
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Legionella pneumophila
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Which of the following fields of study and its example are not correctly matched? parasitology; study of HIV mycology; study of athlete's foot immunology; study of vaccines bacteriology; study of E. coli O157:H7
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parasitology; study of HIV
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In the scientific name, Escherichia coli, Escherichia is the ________.
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genus
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Which of the following types of microorganism and its description is not correctly matched? helminthes; multicellular animals bacteria; prokaryotic fungi; eukaryotic protozoa; small animals
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protozoa; small animals
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All of the following are examples of biotechnology except ________. bread making with bacteria and fungi enzyme production by bacteria and fungi bacteria that cause disease antibiotic production by bacteria
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bacteria that cause disease
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Examples of fungi include the yeasts, molds, and mushrooms.
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True
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Flagella are appendages that allow locomotion in bacteria.
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True
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E. coli O157:H7 is part of the normal microbiota in the human large intestine.
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False
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The avian influenza A virus is transmitted only between birds.
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False
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The vast majority of microbes are harmful to humans or plants.
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False
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The __________ of a compound light microscope focuses light from the light source on the specimen.
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condenser
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Which of the following is the most convenient and appropriate unit for expressing the size of an average bacterial cell?
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micrometer
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All of the following are visible through a compound light microscope except ________.
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0.02-µm ribosome
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Bacterial motility and flagellar movement can readily be viewed using transmission electron microscopy.
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False
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A __________ is equal to 0.000001 m.
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micrometer
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Acid-fast Mycobacteria differ from non-acid-fast bacteria by the presence of ________.
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carbol fuchsin waxy material in their cell wall
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When stained, bacteria in the genus Mycobacterium are __________.
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acid-fast
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When using a 10X ocular lens and a 40X objective, the total magnification achieved is
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400X
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Which of the following is not a modification of a compound microscope?
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electron microscope
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Flagella are too __________ to be seen with the light microscope without adding a mordant.
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small
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Immersion oil acts to decrease refraction of light rays and thus increase resolution.
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True
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In the Gram stain, if the decolorizing step is deleted, gram-negative cells will appear ________ at the completion of the staining procedure.
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purple
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Magnification is the quality of the microscope that allows one to distinguish between two points that are very close together.
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False
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Place these structures of the compound light microscope in the order that light passes through them on the way to the observer's eyes: (1) condenser, (2) ocular lens, (3) illuminator, (4) specimen, (5) objective lens.
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(3) illuminator, (1) condenser, (4) specimen, (5) objective lens, (2) ocular lens.
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Bacterial smears must be heat-fixed before all staining procedures.
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False
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The ________ charge of a basic dye adheres to the ________ charge of bacterial cell surfaces.
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positive; ......negative
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The __________ is the part of the microscope that controls the amount of light entering the condenser.
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diaphragm
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The Gram stain is important in medical microbiology because the results help physicians select appropriate antibiotics for treatment.
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True
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Which of the following kinds of microscopy would be most appropriate for viewing the shape and arrangement of pili or fimbriae on the surface of a bacterial cell?
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scanning electron microscopy
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Which of the following types of microscopy is most useful for viewing the internal structures of unstained specimens?
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phase-contrast
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You are viewing a sputum smear that has been stained with an acid-fast stain. On this smear you see 5-µm- long red cells. You can conclude that ________.
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there are acid-fast bacteria in the specimen
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Consider a gram-positive cell in a hypertonic medium. If the peptidoglycan were damaged, the cell would __________.
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shrink/plasmolyze/collapse
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The motility of bacteria with flagella occurs through a series of "runs" and __________.
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tumbles
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The term describing bacteria with flagella distributed over the entire surface of the cell is __________.
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Peritrichous
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Endoplasmic reticulum that has ribosomes attached to its outer surface is referred to as __________.
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rough ER
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Chemotaxis refers to the ability of microorganisms to ________.
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move toward or away from chemical stimuli
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All of the following are found in the cell walls of gram-positive bacteria except ________.
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lipid A
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Gram-negative cells contain a periplasmic space that is ________.
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rich in degradative enzymes
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All of the following are true of the gram-negative outer membrane except:
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It contains enzymes for energy synthesis.
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A population of bacterial cells has been placed in a very nutrient-poor environment with extremely low concentrations of sugars and amino acids. Which kind of membrane transport becomes crucial in this environment?
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active transport
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Spherical shaped bacteria that divide and remain attached in chainlike patterns are called ________.
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streptococci
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Which of the following statements about a gram-negative cell wall is not true?
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It has teichoic acids.
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Which of the following processes requires energy?
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active transport
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Which of the following bacterial structures are necessary for chemotaxis?
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flagella
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Endospores are:
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Endospores are extremely durable structures that can survive high temperatures.
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The plane in which a bacterial cell divides determines the arrangement of cells.
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True
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The cell membrane is a fluid structure that allows membrane proteins to move freely.
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True
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Acid-fast bacteria demonstrate unique staining properties because of a special protein layer found in their cell walls.
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False
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Penicillin is more effective against gram-negative bacteria than gram-positive bacteria because it specifically interferes with the synthesis of lipopolysaccharide.
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False
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The endosymbiotic theory states that eukaryotic organelles evolved from symbiotic prokaryotes living within other prokaryotes.
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True
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Biological oxidations are also called __________ reactions.
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dehydrogenation
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At the completion of the Krebs cycle, the carbons from glucose are in __________. (name the molecule)
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carbon dioxide
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At the completion of aerobic respiration, energy has been formed. The energy from the oxidation of glucose is stored in __________?
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ATP
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__________ involves an inhibitor that fills the active site of an enzyme and competes with the normal substrate for the active site. (two words)
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competitive inhibition
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For every NADH that is oxidized via the electron transport chain, __________ ATP are formed.
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three
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All of the following pairs are correctly matched except ________.
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oxidation; reaction where electrons are gained
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Competitive inhibition of enzyme action involves ________.
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competition with the substrate for binding at the active site
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During glycolysis, electrons from the oxidation of glucose are transferred to ________.
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NAD+
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Streptococcus bacteria lack an electron transport chain. How many molecules of ATP can a Streptococcus cell net from one molecule of glucose?
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2
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Unlike eukaryotes, in prokaryotes chemiosmosis ________.
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occurs at the plasma membrane and not the mitochondria
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The chemical reactions involved in synthesizing proteins and cell wall peptidoglycan are examples of ________ reactions.
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anabolic
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For a cell, which of the following compounds has the greatest amount of energy per molecule?
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acetyl CoA pyruvate
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The complete oxidation of glucose typically involves which three stages?
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glycolysis, Krebs cycle, and the electron transport chain
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Which of the following mechanisms does not generate ATP using an electron transport chain?
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substrate-level phosphorylation
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Which of the following are products of the light-dependent reactions, on which the light-independent reactions are dependent?
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ATP and NADPH
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Enzymes work most effectively at their optimal temperature and pH.
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True
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Feedback inhibition generally acts on the last enzyme in an anabolic pathway.
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False
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Glycolysis produces ATP through substrate phosphorylation.
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True
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The synthesis of sugars by using carbon atoms from CO2 gas is called carbon fixation.
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True
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Lipids, proteins, and sugars all may serve as substrates of glycolysis.
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False
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The ability of microbes to utilize N2 as a nitrogen source is called __________.
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nitrogen fixation
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Bacterial growth refers to an increase in the __________ of bacterial cells.
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number
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An unknown organism grows at the top of a tube of thioglycolate broth. This organism is best described as a/an __________ for its oxygen requirements.
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aerobe
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Salt agar tends to inhibit the growth of most organisms, except Staphylococcus. This is an example of a/an __________ media.
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selective
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In a/an __________, cells are added to melted agar and poured into a petri dish. (2 words)
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pour plate
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Bacteria require nitrogen for the synthesis of ________.
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proteins
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What do all of these bacteria have in common? Bacteria in the rumen of cattle and sheep Bacteria in a sewage treatment plant Bacteria growing in the middle ear in chronic otitis media Bacteria growing on the teeth in dental plaque
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The bacteria are most likely growing in biofilms.
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An organism that grows both in the presence and the absence of oxygen and uses oxygen when it is available is called a/an ________.
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facultative anaerobe
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A culture medium consisting of agar, peptone, and beef heart extract is a/an ________.
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complex medium
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Niacin, when added to a medium, would be considered a/an Bacteria growing in and on the human body, including normal microbiota as well as pathogens, are classified as ________.
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organic growth factor mesophilic and heterotrophic
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Martian soil is inoculated into a glucose-containing medium. The radioactive form of carbon, 14C, is used in the glucose. After incubation for five days, which of the following would provide evidence suggesting that there is life on Mars?
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radioactive carbon dioxide
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A medium containing lauryl sulfate inhibits growth of gram-positive bacteria. This medium is ________.
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selective
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To look for bacteria that degrade petroleum, a culture medium containing crude oil, sodium nitrate, phosphate buffer, and magnesium sulfate is inoculated with soil. This medium is ________.
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complex
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The following steps occur during binary fission. What is the third step?
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inward growth of membrane After DNA replication and cell elongation, the membrane will grow inward between the two newly formed cells.
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Which biosafety level is described as follows? (open laboratory benchtop, gloves, lab coat, and face/eye protection)
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2
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Psychrotrophic organisms are often responsible for food spoilage in refrigerated foods.
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True
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Adding salts to a solution increases osmotic pressure and is used to preserve food.
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True
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Microaerophiles do not require oxygen for growth.
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False
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Aerotolerant organisms can grow in the presence of oxygen because their cell wall protects them from toxic products of oxygen.
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False
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In a direct microscopic count, dead cells are easily differentiated from live cells.
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False
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__________ has little value as an antiseptic but is important in the mechanical removal of microbes.
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soap
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Oxidizing agents, such as hydrogen peroxide, are useful for irrigating deep wounds where released oxygen will inhibit the growth of __________.
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anaerobic bacteria
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__________ bacteria may survive pasteurization.
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Thermoduric, Endospore-forming, Heat resistant
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Operating rooms may receive ventilation from air that has passed through __________ filters to remove microorganisms.
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high-efficiency particulate air HEPA
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__________ ammonium compounds are less effective against gram-negative bacteria and more effective against gram-positive bacteria.
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Quaternary
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Sterilization is the ________.
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destruction of all life-forms
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An antiseptic Degerming is used to remove microbes from ________.
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skin, before an injection
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Which of the following infectious agents challenges current sterilization strategies that have been accepted and in use for decades?
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prions
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Some antimicrobial treatments kill microbes; some inhibit growth. Which term refers to an agent that inhibits bacterial growth?
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bacteriostatic
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Which of the following is not a major target for action of antimicrobials?
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flagella
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You discover a compound that you suspect reduces spoilage in fruit. You treat apples with your compound and inoculate them with Botrytis, a common spoilage fungus. After seven days the dry weight of fungi on the treated apples is 5 mg and 10 mg on the untreated apples. You conclude from these results that ________. All of the following methods are used for food preservation except ________.
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Since the treatment appears to have slowed fungal growth, we can say that it is fungistatic.
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Decimal reduction time is the time in minutes in which ________ of the population at a given temperature will be killed.
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Decimal reduction time (DRT) is the time it takes with a particular treatment to kill 90% of the microbes.
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Which of these conditions is likely to interfere with the effectiveness of an antiseptic or disinfectant?
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presence of biofilms
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Which one of these substances is effective against bacterial endospores?
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chlorine bleach
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Which of these chemicals is not an oxidizing agent? Some microbes are very resistant to antimicrobial chemicals. Which of the following would be the easiest to kill?
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Triclosan E. coli
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Most viruses are highly resistant to disinfectants and antiseptics.
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False
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The presence of organic matter, such as blood or saliva, may impair the action of antimicrobial chemicals.
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True
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Ethylene oxide gas is used to sterilize medical equipment that might be damaged by exposure to the heat of autoclaving.
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True
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Iodine is one of the least effective antimicrobial chemicals, effective only against certain very sensitive strains of bacteria.
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False
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Soap is ineffective in killing bacteria. Therefore, hand washing is a rather ineffective measure in preventing disease transmission.
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False
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To begin transcription, the RNA polymerase binds a region on DNA known as the __________.
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promoter
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Genes whose products are produced constantly are __________.
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constitutive
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Small stretches of DNA that can move within a genome are referred to as __________.
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transposons
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Most amino acids are encoded by several different codons. This is referred to as the __________ of the genetic code.
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degeneracy
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The transfer of genetic information between organisms through processes such as transduction or conjugation is called __________ gene transfer.
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horizontal
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All of these statements are true of plasmids except:
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They are essential for survival of the organism in most situations.
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Consider the polypeptide sequence encoded by the following DNA: TACAAAGAAATT If base number 6 is changed to G, how will this affect the polypeptide?
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There will be no change in the polypeptide.
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In E. coli, Hfr cells ________. All of these statements are true of base substitutions except ________.
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can pass main chromosome genes to a recipient cell Mutations rarely involve base substitutions.
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Which of these statements is true about transduction?
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A virus is required for transfer of genetic material.
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In the lac operon of E. coli, ________.
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the repressor protein binds to the operator in the absence of lactose
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Which one of the following is a method of vertical gene transmission?
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cell division
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Which of the following requires cell-to-cell contact?
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conjugation
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All of these statements are true about DNA replication except:
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Only one strand of the parent DNA serves as a template for a newly synthesized complementary strand.
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The major source of the genetic diversity among microorganisms upon which natural selection operates is ________.
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mutation
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Which one of the following would be the most likely to yield a recombinant cell after mating? Which of these statements is not true of translation?
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Hfr cell and F- cell Each amino acid is coded for by a single codon.
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In prokaryotes, translation of an mRNA molecule can begin before transcription of the mRNA molecule is completed.
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True
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Codons of mRNA temporarily bond to anticodons of tRNA during translation.
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True
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Mutations are always harmful to cells.
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False
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Hfr cells transfer genes to recipient cells in a particular order. The term phenotype is used to describe all of the organism's genetic information.
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False
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In E. coli, the presence of lactose is necessary and sufficient for induction of the lactose-utilization genes. Mutations are always harmful to cells.
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False
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For the bacterium Staphylococcus aureus, the word Staphylococcus is the genus name and aureus is the __________. (2 words)
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specific epithet
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The process of using restriction enzymes to create DNA fragments that can be separated by electrophoresis and compared is known as __________. (2 words)
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DNA fingerprinting
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Bergey's Manual includes information on two domains: bacteria and __________.
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Archaea
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A map that shows the evolutionary relationships of organisms among organisms is the __________.
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cladogram
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A test that determines which phages a bacterium is susceptible to is called __________. (2 words)
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phage-typing
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Which of the following is not a characteristic of the Archaea?
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cause disease in humans
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Members of the Kingdom Fungi are ________.
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either unicellular or multicellular
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Which of the following is in the correct order?
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Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
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A key difference between classification methods and identification methods is that classification methods are designed to ________.
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determine evolutionary relationships of organisms
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Which of the following is not true for the slide agglutination test?
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The absence of agglutination indicates that the antibody reacted with the antigen. This technique identifies signature rRNA sequences of microbes.
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All of the following are characteristics of prokaryotesexcept ________.
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use mitosis
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The evolutionary history of a group of organisms is called a ________.
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phylogeny
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Which pair of organisms are the most closely related?
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Amanita fungus-human
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Which kingdom includes multicellular organisms with organelles containing a single circular chromosome, 70S ribosomes, and chlorophyll?
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Plantae
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Which of the following is an appropriate definition for a prokaryotic species?
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a population of cells with similar characteristics including structure, morphology, biochemical reactions, surface antigens, and rRNA
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Gram stains alone can be used to identify bacteria.
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False
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Microorganisms must be cultured before they can be identified.
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False
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Neutrophils, basophils, and eosinophils are collectively referred to as __________.
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granulocytes
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The process of coating bacteria with serum proteins to promote attachment of phagocytes is called __________.
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opsonization
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Complement components C5 through C9 form plasma membrane channels in cellular microbes referred to as the __________.
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membrane attack complex MAC
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When blood cells are removed from blood, the remaining liquid is referred to as __________.
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serum
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Body temperature, which can change because of infection, is controlled by a region of the brain known as the __________.
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hypothalamus
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The epidermis ________.
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contains the protein keratin
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The ID50 for many pathogens is significantly smaller when testing with gnotobiotic animals compared to animals with normal microbiota. One reason for this is because gnotobiotic cells would not be protected by ________.
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microbial antagonism
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The etiologic agent of fever blisters is __________.
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Human herpesvirus 1 Herpes simplex virus
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Scabies is a skin disease caused by a/an __________.
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mite
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Infection with __________ causes a disease that closely resembles smallpox.
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monkeypox
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A child with pus-filled vesicles and scabs on his face, throat, and lower back most likely has __________, caused by a herpesvirus infection.
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chickenpox
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Which of the following is not a characteristic of Streptococcus?
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coagulase-positive
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Place the following infections in order of increasing tissue involvement and severity: (1) septicemia, (2) folliculitis, (3) cellulitis, (4) furuncle.
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folliculitis, furuncle, cellulitis, septicemia
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All of the following are characteristics of the varicella-zoster virus except ________.
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benign skin growths
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All of the following cause conjunctivitis except ________.
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Propionibacterium
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Which of the following is not a predisposing condition for candidiasis (yeast infections)?
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fifth disease
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Which of the following is NOT normal skin microbiota?
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Streptococcus
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The yeast Malassezia furfur may be the cause of:
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dandruff
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Microorganisms that produce the enzyme keratinase can grow on ________.
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skin and hair
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Coagulase-negative strains of Staphylococcus are never associated with human disease.
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False
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Impetigo can be caused by either Streptococcus pyogenes, Staphylococcus aureus, or both.
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True
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The most common treatments for tinea are either penicillin or cephalosporin.
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False
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Mycobacterium ulcerans causes a skin infection known as a __________. (2 words)
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Buruli ulcer
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A "teenage disease" called __________ is caused by gram-positive rods than can be isolated from pus-filled cysts on the face and upper back. (1 word)
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acne
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Thrush in children and vaginitis in adults are caused by the fungal genus __________.
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Candida
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German measles infection during the first trimester of pregnancy may result in __________. (3 words)
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congenital rubella syndrome
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The __________ have at least 113 antigenic types and are the most common agent of colds.
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rhinoviruses
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Strains of Mycobacterium tuberculosis that are resistant to all of the first-line drugs and at least half of the second-line drugs are known as __________ tuberculosis. (3 words or initials)
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extensively drug resistant
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Mycoplasma pneumoniae, a frequent cause of pneumonia in children and young adults, is called __________ pneumonia.
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walking/primary atypical
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Large-scale changes in influenza envelope proteins, such as those found in the H5N1 strain, are due to reassortment between different strains. This is called antigenic __________.
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shift
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The walled-off lesions in lung tissue formed by Mycobacterium tuberculosis are called __________.
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tubercles granulomas
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One of the most important reasons to diagnose and treat strep throat is ________.
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Untreated strep throat may contribute to the development of rheumatic fever.
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All of these statements are true of tuberculosis except:
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Infection has been greatly reduced due to mass immunization.
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All of these descriptions pertain to Mycoplasmal pneumonia except ________.
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usually a life-threatening illness in adolescence
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A patient has a rapid onset of fever, headache and chills. He recently returned from Mexico, where he drank local water and stayed in an air-conditioned room. Several weeks ago, he purchased a parrot. After a physical exam, his physician prescribes tetracycline. What is the cause of the patient's illness?
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Chlamydia psittaci
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All of these statements are true of diphtheria EXCEPT
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Patients can be cured using only antibiotics.
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An 81-year-old female has a mass in her lower left lung. Her tuberculin skin test is negative. Microscopic examination of her lung biopsy reveals large, ovoid cells. The patient has ________.
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histoplasmosis
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Which of these answers describes normal microbiota of the respiratory system?
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Microbial antagonism maintains a balance among the normal microbiota.
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A 35-year-old male is hospitalized for cough, fever, and shortness of breath. He is HIV+. Bronchial washings reveal cysts. What is the etiology?
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Pneumocystis
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The following sequence occurs during the initiation of tuberculosis. What is the first step?
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Mycobacteria reproduce in macrophages.
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The catarrhal stage of pertussis is characterized by intense mucus production and violent coughing.
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False
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The common name for the disease caused by Histoplasma capsulatum is valley fever.
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False
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Which of these answers describes normal microbiota of the respiratory system?
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Microbial antagonism maintains a balance among the normal microbiota.
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Legionellosis is a form of pneumonia that does not appear to be transmitted from person to person.
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True
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Respiratory syncytial virus (RSV) is probably the most common cause of viral respiratory disease in adults.
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False
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Influenza vaccines are typically prepared by growing the virus in embryonated eggs.
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True
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