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Antoni van Leeuwenhoek was the first person in history to
A) use a magnifying glass.
B) develop a taxonomic system.
C) view protozoa and bacteria.
D) disprove spontaneous generation.
The microbes commonly known as __________ are single-celled eukaryotes that are generally motile.
Which of the following statements about algae is FALSE?
A) the group includes seaweeds and kelps.
B) they are photosynthetic organisms.
C) they provide most of the oxygen on Earth.
D) they are important in the degradation of dead plants and animals.
Microbes that can live in the presence or absence of oxygen are called
B) facultative anaerobes.
C) obligate parasites.
Which of the following scientists provided evidence in favor of the concept of spontaneous generation?
The microbial production of alcohol from sugar is known as
Which of the following statements about fungi is FALSE?
A) fungi are eukaryotes.
B) molds form hyphae.
C) fungi have a cell wall.
D) fungi are photosynthetic.
E) yeasts are unicellular.
Which of the following statements concerning Koch's postulates is false?
A) Koch's postulates cannot be used to demonstrate the cause of all diseases.
B) A suspected pathogen must be able to be grown in the laboratory.
C) All of Koch's postulates must be satisfied before an organism can be proven to cause a particular disease.
D) Koch's postulates involve the experimental infection of susceptible hosts.
E) A suspected pathogen must be found in the majority of individuals with a particular disease.
Which of the following individuals pioneered the use of chemicals to reduce the incidence of infections during surgery?
The study of the body's defenses against pathogens is called
D) molecular biology.
Which of the following questions largely stimulated the research of microbes during what is known as the Golden Age of Microbiology?
A) What causes disease?
B) How do genes work?
C) Is spontaneous generation of microbes possible?
D) How are microbes related?
E) What causes disease, and is spontaneous generation of microbes possible?
The microbial activity of __________ is responsible for the production of various foods.
E) both fungi and bacteria
What scientist first hypothesized that gene sequences could provide new insights into evolutionary relationships between organisms such as microbes?
Work by __________ laid the foundations of the field of environmental microbiology.
A) Redi and Spallanzani
B) Koch and Pasteur
C) Beijerinck and Winogradsky
D) Lister and Semmelweis
E) Pauling and Woese
According to Kluyver and van Niel, which of the following are true of basic biochemical reactions?
A) They are shared by all living things.
B) There are an unlimited number of them.
C) They primarily involve the transfer of electrons and ions.
D) Basic biochemical reactions shared by all living things primarily involve transfer of electrons and hydrogen ions.
Semmelweis advocated handwashing as a method of preventing which of the following diseases?
B) puerperal fever
Paul Ehrlich used chemotherapy to treat
Which of the following is NOT a characteristic of viruses?
A) they are visible with a light microscope.
B) they are acellular.
C) they are composed of genetic material and protein.
D) they are smaller than prokaryotic cells.
E) they are obligatory parasites.
How are fungal viruses different from viruses that infect other organisms?
A) they have no extracellular state.
B) they have only DNA for genetic material.
C) they have no capsid.
D) they have no intracellular state.
E) they cannot pass through a filter.
How are prions different from all other known infectious agents?
A) they cannot reproduce outside a cell.
B) they act as slow viruses.
C) they cause neurological problems.
D) they can be destroyed by incineration.
E) they lack nucleic acid.
The first true vaccine protected against disease caused by a __________ pathogen.
All of the following individuals were involved in improving public health in the 19th century EXCEPT
Saccharomyces cerevisiae is an example of which of the following types of microbes?
Inserting a gene from the hepatitis B virus into yeast so that the yeast produces a viral protein is an example of
B) genetic engineering.
D) microbial genetics.
E) gene therapy.
Which of the following was NOT an aspect of Pasteur's experiments to disprove spontaneous generation?
A) The necks of the flasks he used were bent into an S-shape.
B) He boiled the infusions to kill any microbes present.
C) The flasks were incubated for very long periods of time.
D) The flasks were free of microbes until they were opened.
E) The flasks he used were sealed with corks.
Proteins that promote chemical reactions in the cell are called
Which of the following is NOT a characteristic of protozoa?
A) most exhibit asexual reproduction.
B) they are single-celled organisms.
C) they are eukaryotic organisms.
D) they are the microbes most similar to plants.
E) they frequently possess cilia or flagella.
Which of the following scientists was the first to develop a taxonomic system for classifying organisms?
Which of the following is NOT an observation Pasteur made concerning the fermentation of grape juice?
A) yeast can grow with or without oxygen.
B) bacteria produce acid in grape juice.
C) pasteurization kills yeast to prevent spoilage of grape juice.
D) yeast cells can grow and reproduce in grape juice.
E) yeast can grow in sealed or open flasks of grape juice.
Put the following events in the history of microbiology in order, from the earliest to the latest:
I. Leeuwenhoek observes microbes using a microscope.
II. Pasteur disproves spontaneous generation.
III. Woese discovers the archaea.
IV. Fracastoro proposes that "germs" cause disease.
V. Ehrlich discovers the first "magic bullet."
A) III, IV, I, II, V
B) V, IV, I, III, II
C) IV, I, V, II, III
D) III, V, II, IV, I
E) IV, I, II, V, III
John Snow's research during a cholera outbreak in London laid the foundation for which of the following branches of microbiology?
A) infection control
D) both infection control and epidemiology
E) infection control, epidemiology, and immunology
Robert Koch was involved in research on all of the following topics EXCEPT
A) the cause of anthrax.
B) the cause of fermentation.
C) development of a method to prove the cause of an infectious disease.
D) the cause of tuberculosis.
E) techniques for isolating microbes in the laboratory.
Which of the following is an incorrect pairing?
A) protozoa: multicellular
B) fungi: cell walls
C) algae: aquatic and marine habitats
D) prokaryotes: no nuclei
E) viruses: acellular parasites
What was the first disease proven to be bacterial in origin?
A) yellow fever
The work of Lister, Nightingale, and Semmelweis all contributed to controlling infectious disease by
A) developing techniques for isolating pathogens.
B) developing methods for reducing nosocomial infections.
C) identifying the sources of infectious agents.
D) determining the taxonomic relationships among microbes.
E) developing vaccines.
Who discovered penicillin?
All of the following were involved in developing the germ theory of disease EXCEPT
Microorganisms characterized by the absence of a nucleus are called
The term that literally means "against putrefaction" is
D) recombinant technology.
The term __________ refers to an infection acquired in a health care setting.
C) spontaneous generation
The term __________ literally means "produces disease."
D) facultative anaerobe
The study of the causation of disease is known as
The term for the use of microorganisms to restore damaged environments is
The term __________ means the study of the blood components that fight infection.
The study of the occurrence, distribution, and spread of disease is known as
C) molecular biology.
Christian Gram devised a staining technique that divides all bacteria into two groups.
3) The production of human blood-clotting factor by E. coli is an example of bioremediation.
Gene therapy is a modern approach to preventing infectious disease.
Koch's postulates can be used only to prove the causes of infectious diseases.
Joseph Lister reduced the incidence of wound infections in health care settings by using chlorinated lime water.
Fermentation can occur in the absence of living cells.
Lazzaro Spallanzani was the first scientist to provide evidence disproving the spontaneous generation of microorganisms.
Microbes that move by means of cilia are __________.
A cell that contains a nucleus is called a(n) __________ cell.
A(n) __________ organism makes its own food using solar energy.
Microbes that cause infectious disease are called __________.
An asexual method of reproduction associated with yeasts is __________.
A(n) __________ is a potential explanation for a set of observations made by a scientist studying a phenomenon.
Bacteria that can live without oxygen are termed __________.
Robert Koch discovered the cause of __________, a disease of animals that can be spread to humans.
A(n) __________ is a mass of cells that are descended from a single cell through successive cell divisions.
The glycocalyx of a eukaryotic cell performs all of the following functions EXCEPT
A) protection against dehydration.
B) anchoring cells to each other.
C) cellular recognition and communication.
D) transfer of genetic material between cells.
E) strengthening the cell surface.
An antimicrobial that inhibits cell wall synthesis will result in which of the following?
A) Cells become more susceptible to osmotic pressure.
B) Cells cannot attach to their hosts.
C) Ribosomes lose their function.
D) The sterols in the cell wall become nonfunctional.
E) The replication of cells, including cancer cells, slows down.
Beta-lactam antibiotics have an effect on which of the following types of cells?
A) animal cells
B) bacterial cells
C) fungal cells
D) virus-infected cells
E) both animal and fungal cells
30) Which of the following cells does NOT have the ability to release histamine?
A) mast cells
D) damaged body cells
42) TLRs are
A) phagocyte receptors that detect PAMPs.
B) the coating of a pathogen by complement.
C) molecules that damage cells, resulting in cell lysis.
D) present in intact skin, sebum, tears, etc.
E) nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
Which of the following produces an exogenous antigen?
A) a bacterium inside a cell
B) a virus inside a cell
C) a bacterium outside a cell
D) a noninfected human cell
E) the malaria parasite inside a red blood cell
The perforin-granzyme pathway involves
A) the production of fever, which kills the pathogen.
B) the production of antibodies toward the invading pathogen.
C) the synthesis of special cell-killing proteins that act on infected or abnormal cells.
D) presenting the foreign antigen to B cells.
E) binding CD95L to infected cells, which eventually leads to cell apoptosis.
The immunological synapse refers to the
A) interaction between a T cell and an antigen-presenting cell to produce a specialized contact area for communication between these cells.
B) activation of a B cell to become a plasma cell.
C) interaction between lymphocytes and foreign antigens to produce memory cells.
D) binding of a monocyte or macrophage to antigen so that it can act as an antigen-presenting cell.
E) interaction of the many cytokines produced by different immunological cells.
Killed vaccines work by stimulating
A) the production of antibodies.
B) the action of Th1 cells.
C) the cell-mediated immune response.
D) cytotoxic T cells.
E) lymphocyte proliferation.
34) The tuberculin response is mediated by
A) memory T cells.
B) mast cells.
C) B lymphocytes.
D) plasma cells.
The first true vaccine provided protection from disease caused by a(n) __________.
Ignaz Semmelweis demonstrated the importance of __________ as a means of preventing disease transmission.
A term synonymous with immunization, __________ is derived from the Latin name of the cowpox virus.
The use of chemicals to treat diseases such as bacterial infections is called __________.
Organisms such as bacteria that can convert atmospheric nitrogen into nitrate are often studied in __________ microbiology.
The __________ of an organism is all the chemical reactions that take place in the organism.
Biotechnology can be said to have ancient roots. Explain.
Use the basic steps of the scientific method to describe Pasteur's experiments to investigate spontaneous generation.
Explain how the discipline of biochemistry grew out of the science of microbiology.
Using a microscope, you observe an amoeba moving toward a food source. This is an example of
B) cellular structure.
Which of the following is NOT a component of bacterial flagella?
B) basal body
Which of the following statements concerning the characteristics of life is FALSE?
A) reproduction is defined as an increase in the size of an organism.
B) viruses have some, but not all, of the characteristics of living things.
C) organisms may not exhibit all of the characteristics of life at all times.
D) reproduction can occur asexually or sexually in living things.
E) living things store metabolic energy in the form of chemicals such as ATP.
Bacterial pili can be described as
A) composed of tubulin.
B) solid, rigid protein structures.
C) composed of peptidoglycan.
D) specialized fimbriae.
E) a means of locomotion.
Which of the following bacterial cell structures plays an important role in the creation of biofilms?
E) both fimbriae and glycocalyces
Short, hairlike structures used only by eukaryotic cells for movement are called
A bacterial cell moving toward light would be an example of
B) positive phototaxis.
C) negative phototaxis.
D) positive chemotaxis.
E) negative chemotaxis.
Which of the following statements concerning prokaryotic flagella is FALSE?
A) Prokaryotic flagella can rotate 360 degrees.
B) A "run" results from counterclockwise movement of the flagellum.
C) Prokaryotic flagella are composed of tubulin.
D) Treponema is an example of a bacterium that has an endoflagellum.
E) Prokaryotic flagella are anchored to the cell wall by means of the basal body.
Which of the following statements concerning pili is FALSE?
A) Pili are longer than fimbriae and flagella.
B) Pili facilitate the transfer of DNA among bacterial cells.
C) Pili are long, hollow tubules.
D) Not all bacteria have pili.
E) A bacterial cell will usually have only one or two pili.
Which of the following is NOT a component of bacterial cell walls?
B) lipoteichoic acids
C) mycolic acid
Bacterial cell walls that are resistant to drying contain
B) amino acids.
Lipid A is also known as
B) teichoic acid.
D) mycolic acid.
Bacteria of the genus Mycoplasma are distinguished from other bacterial cells by
A) unique ribosomes.
B) the presence of mycolic acid in their cell walls.
C) the absence of a cell wall.
D) cell walls composed solely of amino acids.
E) the absence of a cytoplasmic membrane.
Lipid-soluble molecules would be expected to cross the cytoplasmic membrane by which of the following processes?
B) facilitated diffusion
D) active transport
E) group translocation
ATP is expended in which of the following processes?
A) facilitated diffusion
C) group translocation
E) both active transport and group translocation
Which of the following statements concerning osmosis is FALSE?
A) Osmosis requires a selectively permeable membrane.
B) During osmosis, water crosses to the side of the membrane with a lower solute concentration.
C) Cells placed in hypotonic solutions will gain water.
D) Crenation results when cells are placed in a hypertonic solution.
E) Osmosis stops when the system reaches equilibrium.
Endospores survive a variety of harsh conditions in part because of the presence of
A) mycolic acid.
D) dipicolinic acid.
Which of the following is unique to archaea?
When cells are placed in a hypertonic solution, they lose water and shrivel. This process is called
C) passive transport.
Which of the following statements concerning endocytosis and exocytosis is CORRECT?
A) These processes occur in both prokaryotes and eukaryotes.
B) Phagocytosis is a type of endocytosis in which liquids are brought into the cell.
C) Endocytosis produces a structure called a food vesicle.
D) Waste products and secretions are exported from the cell during endocytosis.
E) Endocytosis is a form of passive transport, whereas exocytosis is a form of active transport.
One lipid found in eukaryotes but not in prokaryotes is
D) fatty acid.
Which of the following statements concerning centrioles is FALSE?
A) The structure of centrioles is similar to that of eukaryotic flagella and cilia.
B) Centrioles are believed to play a role in cellular processes such as mitosis and cytokinesis.
C) Centrioles are found in a region of the cell called the centrosome.
D) Centrioles are found in all organisms except prokaryotes.
E) Centrioles are composed of microtubules.
Which of the following is classified as a membranous organelle of eukaryotic cells?
A) endoplasmic reticulum
E) both ribosomes and centrioles
Which of the following is NOT associated with the nucleus of a eukaryotic cell?
Bloom's Rank: Knowledge
Section: Cytoplasm of Eukaryotes
26) Which of the following statements about the endoplasmic reticulum (ER) is CORRECT?
A) The rough ER is the site of lipid synthesis.
B) The smooth ER has ribosomes associated with it.
C) The ER is a lipid storage organelle.
D) The ER is a transport system within the cytoplasm.
E) The smooth ER is a site of ATP synthesis.
Bloom's Rank: Application
27) Which of the following organelles is responsible for producing most of the ATP in a eukaryotic cell?
B) Golgi body
D) smooth endoplasmic reticulum
Which of the following statements about the endoplasmic reticulum (ER) is CORRECT?
Which of the following organelles is responsible for producing most of the ATP in a eukaryotic cell?
Chloroplasts differ from mitochondria in that they have
B) two lipid bilayers.
C) 70S ribosomes.
D) light-harvesting pigments.
Which of the following is paired incorrectly?
A) plants: cellulose cell wall
B) algae: glycocalyx present
C) bacteria: peptidoglycan cell wall
D) fungi: cellulose, chitin, and/or glucomannan cell wall
E) archaea: polysaccharide cell wall
Which of the following statements concerning the endosymbiotic theory is FALSE?
A) Eukaryotes were formed from the union of small anaerobic cells by larger aerobic cells.
B) Mitochondria and chloroplasts can divide independently of the cell.
C) Mitochondria and chloroplasts have their own DNA and ribosomes.
D) The cristae of mitochondria evolved from the cytoplasmic membrane of prokaryotes.
E) The endosymbiotic theory is not universally accepted.
Which of the following is NOT a function of the eukaryotic cytoskeleton?
A) anchors organelles
B) gives shape to the cell
C) packages cellular secretions
D) performs endocytosis
E) aids in contraction of the cell
The accumulation of glucose 6-phosphate inside a bacterial cell via phosphorylation of glucose is an example of
A) facilitated diffusion.
B) group translocation.
Which of the following molecules would be expected to cross the cytoplasmic membrane rapidly and without the use of transport proteins?
A) large molecules
C) small hydrophobic molecules
D) small hydrophilic molecules
E) both ions and hydrophilic molecules
Anabolic reactions may be characterized as
B) breaking large molecules into smaller molecules.
C) forming large molecules from smaller molecules.
D) producing ATP.
E) breaking large molecules into smaller molecules to produce ATP.
Which of the following processes requires a carrier protein?
C) active transport
E) both facilitated diffusion and active transport
Which of the following chemical substances contributes to the unique characteristics of acid-fast bacteria?
C) lipoteichoic acid
E) mycolic acid
The cytoplasmic membranes of __________ contain phospholipids and proteins.
A) archaeal cells
C) eukaryotic cells
D) both bacterial and eukaryotic cells
E) archaeal, bacterial, and eukaryotic cells
Membrane rafts are found in the cytoplasmic membranes of
D) both archaea and bacteria.
E) both archaea and eukaryotes.
Endocytosis and exocytosis are means of transport used by
D) all prokaryotes.
E) no cells use both processes.
Some __________ use group translocation as a means of transport.
E) eukaryotes and prokaryotes
Hopanoids are found in __________ cytoplasmic membranes.
The cell walls of __________ contain peptidoglycan.
E) bacteria and eukaryotes
Cytoplasmic membranes of __________ are composed of phospholipids.
E) both bacteria and eukaryotes
Some members of __________ have hami.
D) both archaea and bacteria
__________ may have pili.
E) Eukaryotes and bacteria
__________ may have flagella.
E) Archaea, bacteria, and eukaryotes
Which of the following may have cell walls containing teichoic acids?
A) Gram-negative bacteria
B) Gram-positive bacteria
D) both Gram-positive and Gram-negative bacteria
E) all prokaryotes
The cell walls of __________ contain tetrapeptides.
C) both Gram-positive and Gram-negative bacteria
Which of the following have external structures containing a periplasmic space?
The cytoplasmic membranes of __________ contain lipids.
Which of the following prokaryotic cells contain an outer membrane?
Chloroplasts use light energy to produce ATP and carbohydrates.
Peroxisomes contain enzymes used to digest nutrients that have been brought into the cell through phagocytosis.
Bacterial protein synthesis can begin before the reading of the gene is complete.
All cell membranes contain phospholipids and a wide variety of proteins.
The process of facilitated diffusion requires an input of energy.
Eukaryotic ribosomes are composed of 60S and 40S subunits.
Lysosomes result from the endocytosis of food particles by eukaryotic cells.
Formation of a biofilm may contribute to bacteria's ability to cause disease.
Chromatin is composed of DNA and special packaging proteins called hopanoids.
The Golgi body prepares cellular products for export.
In a(n) __________ solution, an animal cell can gain so much water that it may burst.
The presence of a cell __________ enables bacterial and plant cells to resist the effects of hypotonic solutions.
A higher concentration of solutes corresponds to a __________ (higher/lower) concentration of water in a given solution.
A(n) __________ is a carrier protein that transports two substances in the same direction across a membrane.
The __________ body anchors the bacterial flagellum in the cell wall.
The reserve deposits of starch or other compounds found in many prokaryotic cells are called __________.
Eukaryotic cells use a process known as __________ to obtain liquids from their environment.
Lipid __________ is a part of the Gram-negative cell wall that can produce fever, inflammation, and shock when it is released into the bloodstream. (Be sure to use capital letters.)
Paired structures composed of tubulin that play a role in eukaryotic mitosis are known as __________.
Fibrous structures some archaea use for attachment to surfaces are __________.
A(n) __________ is a type of glycocalyx that is firmly attached to the cell.
The type of organelles found only in eukaryotic cells are described as __________.
The semiliquid matrix of the nucleus is called the __________.
A structural molecule found in eukaryotic cytoskeletons, flagella, cilia, and centrioles is __________.
Another name for a channel protein in the cell membrane is __________.
Compare and contrast the characteristics of prokaryotic and eukaryotic cells.
Compare and contrast archaea and bacteria, with particular attention to the features that lead to their placement in separate taxa.
Most antibacterial drugs disrupt or destroy bacterial cellular characteristics that are different from those of eukaryotic cells or that may not even be present in eukaryotic cells. List and describe at least three cellular features of bacteria that could be targeted to inhibit or kill a bacterial pathogen.
Describe the similarities and differences between mitochondria and chloroplasts.
Describe how the structure of the bacterial cytoplasmic membrane relates to its function of selective permeability.
Which of the following statements concerning cellular metabolism is FALSE?
A) Energy obtained from nutrients or light is stored in the bonds of ATP.
B) Enzymes are used in both catabolic and anabolic reactions.
C) Macromolecules are converted into cell structures via catabolism.
D) The goal of metabolism is reproduction of the organism.
E) ATP is used in the formation of macromolecules.
Which of the following statements concerning reduction reactions is FALSE?
A) An electron acceptor gains an electron.
B) They are coupled with oxidation reactions.
C) They frequently involve electron carrier molecules.
D) An electron acceptor becomes more positively charged.
E) A molecule gains a hydrogen atom.
The molecule that an enzyme acts upon is known as its
In microbiology, the term growth usually refers to an increase in
A) a microbe's size.
B) the number of microbial cells.
C) the amount of ATP produced.
D) the number and size of microbial cells.
E) the number and size of microbial cells and the amount of ATP produced.
A cell that uses an organic carbon source and obtains energy from light would be called a
A(n) __________ organism is one that requires oxygen for growth.
B) facultative anaerobic
D) obligate aerobic
E) both aerotolerant and anaerobic
An aquatic microbe that can grow only at the surface of the water is probably which of the following?
A) a phototroph
B) a heterotroph
C) a chemotroph
D) a lithotroph
E) an anaerobe
Which of the following forms of oxygen is detoxified by the enzyme catalase?
A) singlet oxygen
B) hydroxyl radical
C) peroxide anion
D) superoxide radical
E) molecular oxygen
All of the following are used to protect organisms from the toxic by-products of oxygen EXCEPT
B) superoxide dismutase.
A microbe that grows only at the bottom of a tube of thioglycollate medium is probably a(n)
A) obligate aerobe.
B) facultative anaerobe.
C) aerotolerant anaerobe.
E) obligate anaerobe.
Nitrogen is a growth limiting nutrient for many organisms because
A) it is necessary for the biosynthesis of amino acids.
B) it is required for synthesis of nucleotides.
C) it is required for lipid synthesis.
D) only a small number of bacteria are able to extract it from the atmosphere.
E) only a few microbes can extract it from the atmosphere, but all organisms require it for amino acid and nucleotide synthesis.
Which of the following growth factors would NOT be required by microbes which do not utilize electron transport chains?
E) amino acids.
At temperatures higher than the maximum growth temperature for an organism,
A) proteins are permanently denatured.
B) membranes become too fluid for proper function.
C) hydrogen bonds within molecules are broken.
D) hydrogen bonds are broken, and proteins are permanently denatured.
E) hydrogen bonds are broken, proteins are denatured, and membranes become too fluid.
Human pathogens are classified as
The term barophile refers to which of the following growth requirements?
A) hydrostatic pressure
C) nitrogen source
E) osmotic pressure
Which of the following organisms would be most likely to contaminate a jar of pickles?
A) a neutrophile
B) a thermophile
C) an acidophile
D) an obligate anaerobe
E) a mesophile
Organisms that can grow with or without oxygen present are
A) obligate aerobes.
C) aerotolerant anaerobes.
D) obligate anaerobes.
E) either facultative anaerobes or aerotolerant anaerobes.
A fastidious organism might be grown on which of the following types of media?
A) transport media
B) reducing media
C) enriched media
D) differential media
E) selective media
Sodium thioglycollate is associated with which of the following types of media?
B) differential media
C) complex media
D) reducing media
Obligate anaerobes may be cultured in the laboratory
A) in a reducing medium.
B) in a candle jar.
C) in standard Petri plates.
D) on blood agar plates.
E) on blood agar plates in a candle jar.
Joan wants to discover a microbe capable of degrading an environmental contaminant. Which of the following refers to the process she should use?
A) cell culture
C) quorum sensing
D) enrichment culture
E) nitrogen fixation
A microbiologist inoculates a growth medium with 100 bacterial cells/ml. If the generation time of the species is 1 hour, and there is no lag phase, how long will it be before the culture contains more than 10,000 cells/ml?
A) 24 hours
B) 7 hours
C) 2 hours
D) 3 hours
E) 10 hours
An epidemiologist is investigating a new disease and observes what appear to be bacteria inside tissue cells in clinical samples from victims. The scientist wants to try to isolate the bacteria in the lab. What culture conditions are most likely to be successful?
A) culturing on blood agar plates
B) inoculation of EMB plates
C) incubation in a candle jar
D) inoculation of cell cultures
E) inoculation of a minimal medium broth
Which of the following measurement techniques would be useful to quantify a species of bacteria that is difficult to culture?
A) membrane filtration
B) viable plate counts
D) microscopic counts
E) metabolic activity
MacConkey agar plates represent __________ medium.
A) a minimal
B) a selective
C) a differential
D) both a differential and a selective
E) both a minimal and a selective
A Petroff-Hauser counting chamber is
A) a glass slide containing an etched grid for counting microbes directly using a microscope.
B) a device that counts cells as they interrupt an electrical current.
C) a device that measures the amount of light that passes through a culture.
D) an apparatus that traps bacterial cells on a membrane filter where they can be counted.
E) a device used to count numbers of bacterial colonies on a Petri plate.
Another term for the logarithmic growth of bacterial cells is
A) generation time.
B) exponential growth.
C) arithmetic growth.
E) binary fission.
A device that removes wastes and adds fresh medium to bacterial cultures in order to prolong the log phase of a culture is called a(n)
A) Coulter counter.
A specimen of urine is determined to contain 30 bacterial cells per microliter. How many cells would be present in a milliliter?
E) 30 million
Which of the following is NOT a direct method for measuring the number of microbes in a sample?
A) viable plate counts
C) Coulter counter
E) membrane filtration
During which growth phase are bacteria more susceptible to antimicrobial drugs?
A) lag phase
B) log phase
C) stationary phase
D) death phase
E) the susceptibility is the same for all phases
During the __________ of growth, new cells are being produced at the same rate as other cells are dying.
C) death phase
D) stationary phase
E) intermediate phase
During the __________ of growth, cells are dying faster than new cells are being produced.
A) death phase
B) lag phase
C) log phase
E) longitudinal phase
When cells are metabolically active but not dividing, they are in the
A) stationary phase.
B) log phase.
C) lag phase.
D) death phase.
E) exponential phase.
The use of salt and sugar in preserving various types of foods is an application of which of the following concepts?
A) nitrogen fixation
B) osmotic pressure
D) hydrostatic pressure
E) quorum sensing
A clinical sample labeled as "sputum" was collected from
A) the skin.
B) the blood.
C) the central nervous system.
D) a piece of tissue.
E) the lungs.
The method of obtaining isolated cultures that utilizes surface area to dilute specimens is called
A) the pour-plate technique.
B) serial dilution.
C) the streak-plate technique.
D) transport media.
E) enrichment culturing.
__________ are complex communities of various types of microbes that adhere to surfaces.
A colony-forming unit is the number of cells
A) in a colony.
B) that produces one colony.
C) in a particular specimen.
D) that is in exponential phase in a culture.
E) that can be placed on a Petri plate.
All of the following ingredients might be found in complex media EXCEPT
A) hydrogen peroxide.
B) yeast extract.
D) soy extract.
E) milk proteins.
Which of the following quantification techniques can distinguish living cells from dead cells in a culture?
A) microscopic counts
B) dry weight
C) metabolic activity
D) a Coulter counter
An organism that tolerates high __________ is called a halophile.
B) salt concentrations
D) carbon dioxide levels
E) oxygen levels
A capnophile is a microorganism that thrives in conditions of high __________.
A) carbon dioxide levels
B) hydrostatic pressure
C) oxygen levels
E) salt concentration
A microorganism found living under conditions of high __________ is a barophile.
A) pH values
B) oxygen concentrations
C) hydrostatic pressure
E) salt concentrations
Microaerophiles are microbes that grow best at low
A) carbon dioxide levels.
B) pH values.
C) hydrostatic pressure.
D) oxygen levels.
E) salt concentrations.
An acidophile thrives under conditions of low
B) salt concentrations.
C) oxygen levels.
D) hydrostatic pressure.
Obligate anaerobes have enzymes such as superoxide dismutase to protect them from the damaging effects of oxygen.
Nitrogen fixation is a process that occurs in all bacteria.
Thermoduric mesophiles are often responsible for spoilage of improperly canned foods.
An obligate halophile will burst if placed in freshwater.
The only effective way to store bacterial cultures for short periods of time is to arrest their metabolism by freezing.
Quorum sensing is a process by which bacteria respond to the density of other bacteria in their environment.
An obligate anaerobe can be cultured in a candle jar.
Agar is a useful compound in the microbiology lab because it is an excellent nutrient for bacteria.
A selective medium can be formulated either by including inhibitory chemical substances or by leaving out a single crucial nutrient.
In spectrophotometry, 40% light transmission is the same thing as 60% absorbance of light.
The conversion of nitrogen gas to ammonia is called nitrogen __________.
Organisms that require organic sources of carbon and energy are called __________.
The __________ radical is formed during the incomplete reduction of O2 during electron transport in aerobes.
The __________ growth temperature is the temperature at which an organism exhibits the highest growth rate.
Bacteria that thrive at human body temperatures are classified as __________.
Alkalinophiles can survive in water up to pH __________. (Be sure your answer is a numeral.)
Cells that are exposed to hypertonic environments will exhibit __________.
A(n) __________ is a sample of microorganisms introduced into a growth medium.
A pure culture is composed of cells that arise from a single __________.
A gelling agent derived from algae that is useful for creating solid growth media is called __________.
A sample placed into fresh medium is typically initially in the __________ phase of microbial growth.
A growth curve plots the __________ of organisms in a growing population over time.
A film of cells at the surface of a broth is called a(n) __________.
A(n) __________ can measure changes in the turbidity of a bacterial culture.
Explain how aerobic organisms tolerate the presence of oxygen in their metabolic pathways despite its toxic properties.
Explain how temperature and pH levels can influence microbial infections in the human body.
Genetic methods of detecting microorganisms reveal that the number of bacterial species in nature exceeds previous estimates by several orders of magnitude. In the human mouth, for example, it is estimated that 500–700 microbial species are normally present. Explain why previous estimates were low.
All of the following are associated with nucleic acid structure EXCEPT
B) hydrogen bonds.
D) ionic bonds.
Which of the following is found at the 5 end of a DNA strand?
A) a phosphate group
B) a hydrogen bond
C) a hydroxyl group
E) a methyl group
The bacterial chromosome is
A) usually circular.
B) found in a nucleoid.
C) found in a nucleus.
D) both circular and found in a nucleoid.
Which of the following types of plasmids allows a bacterial cell to kill its competitors?
A) virulence factors
B) fertility factors
C) bacteriocin factors
D) resistance factors
E) cryptic plasmids
Which of the following is NOT involved the packaging of eukaryotic chromosomes?
E) Okazaki fragments
Which of the following statements is true of bacterial plasmids?
A) They are found in the nucleoid.
B) They can replicate autonomously.
C) They carry genes for essential metabolic functions.
D) They are small circular DNA molecules.
E) They are small circular DNA molecules that can replicate autonomously.
A) break hydrogen bonds between complementary nucleotides.
B) synthesize short DNA molecules important for the function of DNA polymerase.
C) seal gaps between DNA fragments.
D) proofread DNA molecules.
E) assist in recognition of promoters during transcription.
Which of the following is NOT a characteristic of Okazaki fragments?
A) They are checked for accuracy by DNA polymerase III.
B) They make up the lagging strand of replicated DNA.
C) They begin with an RNA primer.
D) They are joined together by DNA ligase.
E) They are longer in eukaryotic cells.
Which of the following is a DNA repair enzyme activated by visible light?
B) DNA photolyase
D) DNA ligase
The energy required for DNA replication comes from
A) DNA polymerase.
B) triphosphate deoxyribonucleotides.
C) DNA ligase.
D) RNA primer.
E) the leading strand.
Which of the following statements concerning transcription in bacteria is FALSE?
A) It occurs in the nucleoid region.
B) Sigma factors are parts of RNA polymerase that recognize promoter regions.
C) The same RNA polymerase transcribes primer RNA, mRNA, tRNA, and rRNA.
D) Termination is either self-induced or due to the presence of Rho protein.
E) There are a variety of sigma factors that affect transcription.
Which of the following is involved in translation?
D) both mRNA and tRNA
Which of the following is a characteristic shared by DNA and RNA polymerases?
A) efficiency of proofreading
B) type of nucleotides used
C) direction of polymerization
Which of the following is the strongest base pair?
E) both adenine-uracil and adenine-thymine
A codon is a particular combination of three nucleotides. Therefore, there are __________ possible combinations of the nucleotides A, C, G, and T.
The AUG codon functions in coding for the amino acid methionine and as a
A) termination signal.
B) start signal.
C) "wobble" codon.
D) marker for introns.
E) recognition site for RNA polymerase.
Which of the following must be removed from a eukaryotic mRNA molecule before it can be translated?
A charged tRNA first enters the ribosomal __________ site and then moves into the __________ site.
A) A, E
B) P, A
C) P, E
D) A, P
E) E, A
Which of the following statements regarding eukaryotic transcription is FALSE?
A) Transcription occurs in the nucleus, mitochondria, and chloroplasts (if present).
B) Multiple transcription factors are required.
C) There are four different RNA polymerases.
D) Multiple elongation factors are required.
E) A guanine is added to the 3 end, and a poly-A tail is added to the 5 end of the mRNA transcript.
Semiconservative DNA replication means that
A) each daughter DNA molecule is composed of one original strand and one new strand.
B) nucleotides are constantly being recycled as cells make DNA.
C) the cell can proofread its newly synthesized DNA only part of the time.
D) the sequence of a DNA molecule is preserved as it is being replicated.
E) each strand of a double-stranded DNA molecule is replicated differently.
The proofreading function of DNA polymerase III results in an error rate of __________ during DNA replication.
A) 1 error in 1,000 bases
B) 1 error in 100,000 bases
C) 1 error in 1 million bases
D) 1 error in 10 million bases
E) 1 error in 10 billion bases
Which of the following processes is involved in the "central dogma" of genetics?
C) DNA replication
D) transcription and translation
E) DNA replication and translation
A) are active in the presence of a repressor.
B) are generally anabolic pathways.
C) are normally active.
D) usually require an activator to be transcribed.
E) usually require a repressor to be transcribed.
Which of the following are considered to be frameshift mutations?
D) both inversion and insertions
E) both deletions and insertions
If the codon AAA is changed to AAG, it still codes for the amino acid lysine; this is an example of a
A) silent mutation.
B) nonsense mutation.
C) frameshift mutation.
D) gross mutation.
E) missense mutation.
Which of the following causes mutations by creating thymine dimers?
A) nucleotide analogs
B) nitrous acid
C) ultraviolet light
E) gamma rays
DNA damage caused by ethidium bromide results in __________ mutations.
D) both inversion and insertion
The Ames test proves that a chemical is
B) carcinogenic in Salmonella.
C) mutagenic in Salmonella.
D) carcinogenic in humans.
The horizontal transfer process known as transduction
A) involves a virus.
B) requires a pilus.
C) requires a cell to be "competent."
D) requires a plasmid.
E) involves a mutagen.
Frederick Griffith discovered
C) the lac operon.
In conjugation, F+ cells
A) serve as recipient cells.
B) contain an F plasmid.
C) do not have conjugation pili.
D) can transfer DNA only to other F+ cells.
E) contain "jumping genes."
Another term for the palindromic sequence found at the ends of transposons is a(n)
A) complex transposon.
C) insertion sequence.
D) inverted repeat.
Which of the following is characteristic of prokaryotic genomes but not eukaryotic genomes?
B) circular chromosomes
C) linear chromosomes
D) enclosed in a nuclear membrane
Genes are active in a region of the eukaryotic chromosome called
B) the histone.
C) the nucleoid.
D) the plasmid.
Which of the following is NOT involved in the regulation of the lac operon?
A) an inducer
B) a repressor protein
C) an iRNA
E) cyclic AMP
Genetic elements known as promoters are initiation points in the process of
A) DNA replication.
D) mutation repair.
Codons are recognized during
C) base excision.
D) DNA replication.
__________ is initiated at sequences called origins.
A) DNA replication
The process of __________ requires the activity of DNA ligase.
D) DNA replication
RNA polymerase is primarily responsible for
The process of __________ requires participation of tRNA molecules.
E) dark repair
The process of __________ is initiated with the incorporation of fMet.
E) light repair
Initiation of __________ involves Sigma factor molecules.
The process of __________ is described as semiconservative.
C) mismatch repair
E) DNA replication
During __________, the growing polymer is located in the P site.
B) DNA replication
Prokaryotic cells are diploid.
The structure of DNA explains both its ability to encode genetic information and the way in which it is copied during cell reproduction.
A(n) __________ is a specific sequence of nucleotides that codes for a protein or an RNA molecule.
A(n) __________ is a mutant organism that has different nutritional requirements from the original wild-type organism.
5-bromouracil mimics the chemical structure of thymine, making it a(n) __________ of thymine.
Transfer RNA molecules carrying amino acids initially bind to the ribosome at the __________ site. (Be sure to use capital letters.)
The ________ of a transfer RNA molecule is complementary to a codon in a messenger RNA molecule.
dATP and dCTP are examples of triphosphate __________, the building blocks of DNA molecules.
The __________ is the set of genes in the genome of an organism.
RNA polymerase initiates transcription by recognizing specific nucleotide sequences called __________.
Pre-messenger RNA molecules contain both __________ and exons. (Be sure your answer is plural.)
Describe the various types of nucleic acids that are typically found in cells.
) A point mutation can be completely harmless, or it can result in the death of a cell or organism. Explain why these types of mutations can have such varying effects.
Standard methods of sterilization are not effective in inactivating
B) bacterial cells.
D) bacterial endospores.
Which of the following statements is true of disinfectants?
A) Disinfectants are effective in destroying endospores.
B) Disinfectants are used on living tissue.
C) Disinfectants are used for sterilization.
D) Disinfectants are used on inanimate surfaces.
E) Disinfectants are only effective for short periods of time (seconds to minutes).
Which of the following statements concerning microbial death is FALSE?
A) It can be used to evaluate the efficacy of antimicrobial agents.
B) It is constant over time of exposure to an antimicrobial agent.
C) It is the permanent loss of a microbe's reproductive ability.
D) It is the permanent loss of a microbe's ability to reproduce and can be used to evaluate antimicrobial agents.
E) It is not an effective means of evaluating the efficacy of antimicrobial agents.
Which of the following is an example of sanitization?
A) A public toilet is treated with disinfectants.
B) A surgeon washes her hands before surgery.
C) Heat is used to kill potential pathogens in apple juice.
D) An autoclave is used to prepare nutrient agar.
E) A nurse prepares an injection site with an alcohol swab.
B) free of all microbes.
E) free of pathogens.
Which of the following would NOT be bacteriostatic?
B) freezing below 0°C
E) refrigeration of mesophiles
Antimicrobial agents that damage nucleic acids also affect
A) the cell wall.
B) the cell membrane.
C) the viral envelope.
E) protein synthesis.
Seventy percent alcohol is effective against
A) enveloped viruses.
B) nonenveloped viruses.
C) bacterial endospores.
D) protozoan cysts.
An instrument that will come into contact with only the skin of a patient should be disinfected with a(n)
A) high-level germicide.
B) low-level germicide.
C) intermediate-level germicide.
D) degerming agent only.
E) germistatic agent only.
Which of the following is NOT an effective means of sterilization?
A) ionizing radiation
E) dry heat
Which of the following describes flash pasteurization?
A) heating at 63°C for 30 minutes
B) heating at 72°C for 15 seconds
C) heating at 72°C for 15 minutes
D) heating at 134°C for one second
E) passing liquid through steam at 140°C
The dairy creamer used in restaurants is usually sterilized by
B) ionizing radiation.
D) UHT sterilization.
Boiling water for 10 minutes is effective in ridding it of
A) actively growing bacteria.
B) enveloped viruses.
E) both growing bacteria and enveloped viruses.
Which of the following is NOT a feature associated with filtration?
A) nitrocellulose or plastic membrane filters
B) sterilization of heat-sensitive materials
C) varying thicknesses of membrane filters used
D) use of HEPA filters to filter air
E) ability of some filters to trap viruses and proteins
Which of the following is a target of pasteurization?
A) Bacillus stearothermophilus
B) Clostridium botulinum
C) Neisseria gonorrhoeae
D) Chlamydia trachomatis
E) Brucella melitensis
Which of the following types of radiation is nonionizing and has the shortest wavelength?
A) ultraviolet light
B) infrared radiation
D) X rays
Which of the following is used for microbial control in fresh fruits and vegetables?
A) X rays
B) ultraviolet light
C) electron beams
Which of the following can be used to disinfect air?
A) HEPA filters
B) ethylene oxide
D) both HEPA filters and ultraviolet light
E) both ethylene oxide and ultraviolet light
Lysol is an example of which of the following groups of chemical antimicrobial agents?
Which of the following is the most appropriate pairing of microbe and biosafety level?
A) E. coli, BSL-3
B) anthrax, BSL-1
C) Ebola, BSL-2
D) methicillin-resistant Staphylococcus aureus (MRSA), BSL-2
E) tuberculosis, BSL-1
Betadine is an example of which of the following groups of antimicrobial agents?
B) heavy metals
Which of the following statements about quaternary ammonium compounds is FALSE?
A) They are a type of detergent.
B) Zephiran is an example of a quat.
C) They are not effective against Pseudomonas aeruginosa.
D) They function by cross-linking proteins.
E) They are harmless to humans except at high concentrations.
Which of the following is a sterilizing agent?
B) hydrogen peroxide
C) peracetic acid
D) dish soap
Which of the following was used in the past to prevent the transmission of gonorrhea from an infected mother to her newborn?
A) hydrogen peroxide
E) silver nitrate
Which of the following is used to sterilize items that should not, or cannot, be exposed to heat or water?
A) ethylene oxide
C) hydrogen peroxide
D) calcium hypochlorite
Which of the following statements about aldehydes is FALSE?
A) They are used only to preserve dead tissues.
B) They denature proteins.
C) Some aldehydes can sterilize after long periods of exposure.
D) They are usually hazardous to humans.
E) They are used in aqueous solutions.
Disinfecting agents naturally produced by microorganisms are
A chemical agent that kills pathogenic microbes in general is a(n)
Which of the following is NOT a desirable characteristic of an ideal antimicrobial agent?
A) it is inexpensive.
B) it is stable during storage.
C) it is harmless to humans.
D) it only arrests growth of vegetative cells.
E) it acts quickly.
The endospores of which of the following microbes are used to measure the effectiveness of autoclave sterilization?
A) Clostridium botulinum
B) Neisseria gonorrhoeae
C) Bacillus stearothermophilus
D) Pseudomonas aeruginosa
A scientist develops a new medication that is a protein compound and that must be administered by injection. Which of the following would be the most effective and safest means of preparing a sterile solution of the new medication?
C) dilution with alcohol
E) ultraviolet irradiation
Which of the following procedures is currently the standard test used in the United States for evaluating the efficiency of antiseptics and disinfectants?
A) use-dilution test
B) microbial death rate
C) in-use test
D) thermal death point
E) phenol coefficient
Which of the following would be used to sterilize a mattress?
C) ethylene oxide
D) heavy metals
Disinfectants that damage membranes include
D) hydrogen peroxide.
Which of the following antimicrobial agents is the most toxic to humans?
A) 70% alcohol
The process of filtration is a(n)
A) disinfectant method.
B) sterilizing method.
C) sanitization method.
D) antiseptic procedure.
E) ineffective method for removing microbes.
Hydrogen peroxide is a(n)
A) sterilizing agent.
B) disinfecting agent.
D) disinfecting and sterilizing agent.
E) ineffective method of disinfecting.
The process of incineration is used for
D) both disinfection and sanitization.
Alcohols are used for
D) both sterilization and disinfection.
E) both antisepsis and disinfection.
The chemical agents known as "quats" are used for
D) quantifying antimicrobial activity.
E) neither antisepsis nor disinfection.
The compound ethylene oxide is used in
Glutaraldehyde is used for
E) both disinfection and sterilization.
__________ may be achieved using chlorine dioxide.
E) Both antisepsis and degerming
Gamma irradiation is a process for
__________ can be accomplished using boiling water.
E) Both disinfection and sanitization
Some viruses are inactivated by the same chemical or physical agents that damage cytoplasmic membranes.
UV light has the most effect on protein structure.
Slow freezing is more damaging to microbial cells than quick freezing.
Natural antiseptics such as pine or clove oil are examples of antimicrobial compounds called __________.
The lowest temperature that kills all cells in a broth in 10 minutes is knows as the __________ death point.
A(n) __________ is an instrument that sterilizes by exposing materials to steam under pressure.
BSL-4 is the appropriate __________ level when handling highly contagious deadly microbes.
Heavy metal and oxidizing agent disinfectants damage __________, interfering with microbial metabolism.
The use of high levels of salt or sugar in the preservation of food relies on the phenomenon of __________ pressure.
Some sterilization procedures do not kill all the microbes that may be present. Explain how these procedures can still be considered sterilization.
What is the in-use test, and why is it more useful than other methods of evaluating disinfectants?
Some physical methods of microbial control that work by removing microbes are just as effective as agents that kill or inhibit these microbes. Explain why this is so, and give some examples of these types of agents.
A student is shopping for antibacterial hand cleansers and is trying to decide which one to buy. One is a "waterless" hand gel containing 70% isopropanol, the second is an "antibacterial" hand soap containing triclosan (a phenolic), and the third is a wipe that lists benzethonium chloride (a synthetic quaternary ammonium salt) as the active ingredient. Compare and contrast these cleansers in terms of the action of the antimicrobial ingredient and the level of disinfection (degerming, germistatic, germicidal).
Which of the following is a primary advantage of semisynthetic drugs?
A) They are less stable and consequently have fewer side effects.
B) They work faster.
C) They have a broader spectrum of action.
D) They must be administered intravenously.
E) They are not readily absorbed, so they persist longer.
Which of the following drugs specifically targets cell walls that contain arabinogalactan-mycolic acid?
Which of the following antibiotics disrupts cytoplasmic membrane function?
E) amphotericin B
Which of the following is NOT a target of drugs that inhibit protein synthesis?
A) the shape of the 30S ribosomal subunit
B) interference with alanine-alanine bridges
C) the enzymatic site of the 50S ribosomal subunit
D) movement of the ribosome from one codon to the next
E) the tRNA docking site
Which scientist coined the term antibiotic?
The most limited group of antimicrobial agents is the __________ drugs.
Another term for the Kirby-Bauer test is the
A) minimum inhibitory concentration test.
B) E test.
C) diffusion susceptibility test.
D) minimum bactericidal concentration test.
E) broth dilution test.
which of the following tests is most effective in determining whether someone has been infected with the H1N1 influenza virus?
A) a viral neutralization test
B) an immunodiffusion test
C) a viral hemagglutination test
D) an antibody titer test
E) a western blot
Tuberculosis may be diagnosed using
A) a direct fluorescent antibody test.
B) complement fixation.
D) a western blot test.
E) a viral hemagglutination test.
Infection with Neisseria gonorrhoeae can be detected in specimens by the
A) direct fluorescent antibody test.
B) indirect fluorescent antibody test.
C) hemagglutination test.
D) complement fixation test.
E) ELISA test.
Which of the following statements about the zone of inhibition is FALSE?
A) It is measured as a diameter.
B) The larger the zone, the more resistant the organism is.
C) It is a clearing zone with no growth.
D) It is a result of diffusion of the drug out of the paper disk.
E) It is measured after incubation.
Which of the following groups of drugs can become incorporated into the bones and teeth of a fetus?
Which of the following can result when antibiotic therapy disrupts the normal microbiota?
A) anaphylactic shock
B) black hairy tongue
C) pseudomembranous colitis
Which of the following statements concerning development of antibiotic resistance is FALSE?
A) It is often mediated by R-plasmids.
B) Resistant cells are normally in the minority in a bacterial population.
C) Resistant cells grow more efficiently and quickly than susceptible cells.
D) New resistance genes can be gained through transformation, transduction, or conjugation.
E) Resistance can occur through mutation of existing bacterial genes.
β-lactamase production is an example of which of the following types of resistance?
A) alteration of the target of the drug
B) inactivation of the drug
C) change in the permeability of the drug
D) overproduction of an enzyme in a key metabolic pathway
E) removal of the drug via a pump
A) involve microbial antagonism.
B) are an alternative to the use of chemotherapy.
C) involve the use of extracts from microorganisms.
D) is a term for resistance to antibiotics.
E) are an alternative to the use of chemotherapy involving microbial antagonism.
Most drugs that inhibit the synthesis of the cell wall act by
A) preventing the cross-linkage of NAM subunits.
B) blocking the secretion of cell wall molecules from the cytoplasm.
C) preventing the formation of alanine-alanine bridges.
D) disrupting the formation of the mycolic acid layer of the cell wall.
E) preventing the formation of β-lactamases.
Most broad-spectrum antibiotics act by
A) inhibiting the synthesis of the cell wall.
B) inhibiting protein synthesis.
C) inhibiting nucleic acid synthesis.
D) inhibiting metabolic pathways.
E) disrupting the cytoplasmic membrane.
The antimicrobials called quinolones act by
A) disrupting cytoplasmic membranes.
B) inhibiting cell wall synthesis.
D) inhibiting a metabolic pathway.
E) inhibiting protein synthesis.
The mechanism of action of the antibiotic vancomycin is
A) inhibition of protein synthesis.
B) inhibition of cell wall synthesis.
C) inhibition of nucleic acid synthesis.
D) inhibition of a metabolic pathway.
E) disruption of cytoplasmic membranes.
Trimethoprim is an example of antimicrobials that
A) disrupt cytoplasmic membranes.
B) inhibit cell wall synthesis.
C) inhibit nucleic acid synthesis.
D) inhibit metabolic pathways.
Which of the following antifungals works by inhibiting ergosterol synthesis?
C) amphotericin B
E) both fluconazole and turbinafine
A) are antimetabolic drugs.
B) were the first widely used antimicrobial drugs.
C) indirectly inhibit the synthesis of nucleic acids.
D) are no longer widely used.
E) were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis.
Which of the following pathways is specifically inhibited by sulfonamides?
A) the conversion of tetrahydrofolic acid to PABA
B) the conversion of PABA to dihydrofolic acid
C) the conversion of dihydrofolic acid to tetrahydrofolic acid
D) the conversion of PABA to tetrahydrofolic acid
E) the conversion of dihydrofolic acid to PABA
Which of the following drugs inhibits nucleic acid synthesis specifically in prokaryotes?
The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid, a β-lactamase inhibitor, is known as
A) cross resistance.
D) selective toxicity.
Alterations in the structure of which of the following are an important aspect of Gram-negative bacterial resistance to antimicrobial drugs?
D) cytoplasmic membrane
It is inappropriate to prescribe antibacterial agents to treat colds or flu because
A) the microbes involved can develop resistance rapidly.
B) these diseases are transmitted by endospores, which are hard to kill.
C) these diseases exhibit cross resistance.
D) these diseases are caused by viruses.
E) these diseases can act synergistically with each other.
Who discovered the first widely available antibiotic?
E) Ehrlich and Waksman
Which of the following statements is true of selective toxicity?
A) Selective toxicity takes advantage of structural differences between host and pathogen.
B) To be effective, an antimicrobial agent must be more toxic to the patient than the pathogen.
C) Selective toxicity takes advantage of metabolic differences between host and pathogen.
D) Antimicrobial agents must target structural differences between host and pathogen and be more toxic to the patient than the pathogen.
E) Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.
Antimicrobials that block protein synthesis by binding to the mRNA are
B) antisense nucleic acids.
E) nucleic acid analogs.
The Etest determines which of the following?
D) both susceptibility and MIC
E) both MBC and MIC
Which of the following is NOT a criterion by which all antimicrobial agents can be evaluated?
A) their spectrum of action
B) their efficacy
C) their activity against cell walls
D) their route of administration
E) their safety
Which of the following interferes with cell wall synthesis by blocking alanine bridge formation?
E) both cycloserine and vancomycin
Antimicrobial sugar analogs are effective for
A) preventing bacterial protein synthesis.
B) preventing cell membrane synthesis.
C) preventing virus attachment.
D) preventing nucleic acid synthesis.
E) blocking a metabolic pathway.
Which of the following is a measurement associated with the broth dilution test?
A) the zone of inhibition
B) lack of turbidity
C) cell lysis
D) lack of turbidity and zone of inhibition
Infection of the __________ would be the hardest to treat with antimicrobial drugs.
Disruption of the normal microbiota can result in infections caused by which of the following microbes?
B) Candida albicans
C) Clostridium difficile
D) both Mycobacterium and Clostridium difficile
E) Candida albicans, Mycobacterium, and Clostridium difficile
Amphotericin B is an antifungal drug that
A) inhibits protein synthesis.
B) inhibits nucleic acid synthesis.
C) blocks a metabolic pathway.
D) disrupts cytoplasmic membranes.
E) inhibits cell wall synthesis.
The tetracyclines interfere with
A) protein synthesis.
B) cell wall synthesis.
C) cell membrane component synthesis.
D) nucleic acid synthesis.
Ribavirin is an antiviral that interferes with
E) viral attachment.
Secondary infections that result from the killing of the normal microbiota are called __________.
Competition between beneficial microbes and potential pathogens is called microbial __________.
Which of the following bacterial arrangements is the result of snapping division?
Which of the following is NOT associated with Corynebacterium?
C) binary fission
What bacterial structure is responsible for separating the daughter DNA molecules after replication?
A) cross wall
B) cytoplasmic membrane
A) are bacterial reproductive structures.
B) can be produced when nutrients are scarce.
C) are produced by bacteria, algae, and fungi.
D) are resistant to everything except radiation.
E) can last for only about 100 years.
Bergey's Manual contains
A) classification schemes for prokaryotes.
B) treatments for bacterial diseases.
C) recipes for bacterial growth media.
D) genetic sequences of prokaryotes.
E) rules for naming new bacterial species.
Which of the following characteristics does NOT distinguish the archaea from the bacteria?
A) the types of transfer RNA used
B) the rRNA sequences present
C) the deoxyribonucleotides
D) cell wall composition
The archaea known as halophiles
A) require temperatures above 45C to survive.
B) require salt concentrations of 9% or greater to survive.
C) are members of the phylum Euryarchaeota.
D) are members of the Euryarchaeota and require temperatures above 45C.
E) are members of the Euryarchaeota and require salt concentrations above 9%.
The largest known group of archaea is the
Which of the following types of microbes might be found in the Dead Sea?
B) phototrophic bacteria
Which of the following groups of bacteria lives in environments similar to those that may have existed on the early Earth?
A) deeply branching bacteria
Which of the following statements regarding cyanobacteria is FALSE?
A) They are oxygenic.
B) Many perform nitrogen fixation.
C) They contain chlorophyll a.
D) They may have given rise to mitochondria.
E) Some are motile.
Heterocysts are associated with
Low G + C Gram-positive bacteria are
B) in the phylum Firmicutes.
D) in the phylum Actinobacteria.
E) in the phylum Firmicutes and include Clostridia and Mycoplasma.
Which of the following diseases is NOT associated with clostridia?
Mycoplasmas are pleomorphic because they
A) have no cell walls.
B) are low G + C Gram-positive bacteria.
C) exhibit snapping division.
D) have sterols in their cytoplasmic membranes.
E) produce endospores.
Which of the following bacterial genera produce(s) endospores?
D) both Bacillus and Lactobacillus
E) both Bacillus and Clostridium
Which of the following bacterial genera includes species that protect areas of the body such as the intestinal tract and the vagina from invasion by pathogens?
Which of the following groups of bacteria is named for its resemblance to fungi?
Which of the following bacterial genera is used for the degradation of environmental pollutants?
Which of the following is NOT associated with bacteria in the genus Streptomyces?
A) the "musty" smell of soil
B) nutrient recycling in soil
C) antibiotic production
D) microbial antagonism
Which of the following characteristics is the basis for distinguishing classes of proteobacteria?
A) outer membrane carbohydrates
B) cell wall structure
C) G + C ratio
D) ribosomal RNA sequences
Proteobacteria, which are facultative anaerobes commonly found in mammalian intestines, are members of the
Members of which of the following genera are the most common sexually transmitted bacteria in the United States?
Which of the following genera does NOT include intracellular parasites of other cells?
Unusual cellular extensions called prosthecae are associated with which of the following groups of proteobacteria?
Which of the following bacterial genera plays an important role in environmental nitrogen cycles?
D) both Nitrobacter and Rhizobium
E) Nitrobacter, Rhizobium, and Azospirillum
Microbes growing in boiling hot mineral springs are generally
D) purple sulfur bacteria.
Classification of bacteria into different phyla is based on comparisons involving which of the following?
A) DNA sequences
B) cell wall composition
C) protein sequences
D) both DNA and protein sequences
Bacteria that require hydrogen sulfide are generally members of the
A) green phototrophic bacteria.
Which of the following statements regarding pseudomonads is FALSE?
A) They are Gram-negative rods.
B) They are symbiotic with plants for nitrogen fixation.
C) They often contaminate food products.
D) They include Pseudomonas and Azotobacter.
E) They cause urinary tract infections.
Which of the following bacterial genera is useful for sewage treatment?
A flexible, spiral-shaped bacterium is called a
The "giant" bacterium Epulopiscium reproduces by means of
A) binary fission.
B) snapping division.
D) sexual reproduction.
Which of the following statements regarding mycoplasmas is FALSE?
A) They are low G + C bacteria.
B) They stain Gram-positive.
C) They are pleomorphic.
D) They exhibit a "fried egg" appearance on solid media.
The anaerobic Clostridium species are troublesome pathogens largely because of their capacity for
A) endospore production.
B) rapid reproduction.
C) oxygen production.
D) biofilm production.
Prokaryotes of the genus Pyrodictium are
A) endospore formers.
B) intracellular parasites.
C) members of the deeply branching bacteria.
The __________ include the genus Aquifex.
C) deeply branching bacteria
D) high G + C Gram-positive bacteria
The bacterium Bacillus cereus is
A) an endospore former.
B) a frequent contaminant of milk and meat.
C) responsible for food poisoning from rice.
D) the cause of gastric ulcers.
E) an endospore former responsible for food poisoning from rice.
Listeria is responsible for
A) gastric ulcers.
B) contaminated milk and meat.
C) urinary tract infections.
E) "flesh-eating" bacterial infections.
One species of the genus Streptococcus is the leading cause of
B) urinary tract infections.
C) contaminated milk and meat.
D) "flesh-eating" bacterial infections.
E) food poisoning from rice.
The genus Mycobacterium includes species responsible for
C) food poisoning from contaminated dairy products.
D) gastric ulcers.
The genus Helicobacter is responsible for
A) food poisoning from contaminated meat.
B) food poisoning from rice.
C) gastric ulcers.
E) urinary tract infections.
Members of the genus Chlamydia are
C) classified with the deeply branching bacteria.
E) Gram-positive bacteria.
Pseudomonas species are occasional causes of
C) food poisoning from dairy products.
D) "flesh-eating" bacterial infection.
The majority of archaea are extremophiles.
Halophiles grow equally well in the presence or absence of high salt concentrations.
Cyanobacteria contain chlorophyll a and carry out anoxygenic photosynthesis.