Chapter 1: Introduction to Microbiology

A) the culture is between 24 and 48 hours old.

All of the following can make interpreting the Gram stain difficult except A) the culture is between 24 and 48 hours old. B) testing bacteria that have a waxy cell wall. C) testing bacteria that are forming endospores. D) the culture is more than 48 hours old and contains damaged cells. E) testing bacteria with especially resistant cell walls.

C) have a survival advantage in areas where malaria is common.

Carriers of the sickle-cell gene A) are more likely to die from a malaria infection. B) are more susceptible to contracting malaria. C) have a survival advantage in areas where malaria is common. D) are often found in high concentrations in U.S. cities. E) experience painful changes in nerve cell shape

B) tuberculosis and leprosy.

The acid-fast stain is an important diagnostic tool for detecting the causative agent(s) of A) gonorrhea. B) tuberculosis and leprosy. C) plague. D) malaria. E) Lyme disease and necrotizing fasciitis.

C) isolate a pure culture for study from a single colony.

The goal of the streak plate technique is to A) compare all of the colonies on a plate with a mixed culture. B) visualize all of the colonies on a plate from a pure culture. C) isolate a pure culture for study from a single colony. D) spread out a thick layer of bacteria and isolate the bacteria that outcompete the rest. E) compare how the shape, color, and margin differ in colonies from a pure culture.

A) as long as nothing unintended touches the media, there will be no contamination.

When practicing aseptic culturing techniques, it is important to keep all of the following in mind except A) as long as nothing unintended touches the media, there will be no contamination. B) the media used to grow the specimen is sterile. C) all of the instruments and lab ware that directly touch the specimen is sterile. D) surrounding surfaces are decontaminated before and after handling cultures. E) gloves and other protecting clothing may be required depending on the specimen being used.

E) size, shape, and cellular arrangement

Which of the following can be determined using simple stains? A) the presence of a waxy cell wall B) the number and position of flagella C) the presence of capsules D) the presence of endospores E) size, shape, and cellular arrangement

A) Uncovered meat will give rise to maggots.

Which of the following could be used as evidence for spontaneous generation? A) Uncovered meat will give rise to maggots. B) The meat in gauze-covered jars will not give rise to maggots. C) The broth in Pasteur's S-necked flasks did not spoil. D) Tilting Pasteur's S-necked flasks did spoil the broth. E) Flies lay eggs that develop into maggots

D) proper hand-washing technique

Which of the following does not contribute to shifts in our normal microbiota? A) hormonal changes B) diet C) age D) proper hand-washing technique E) our general environment

E) consistent flame sterilization on the inside surfaces.

A biological safety cabinet minimizes the chances of contaminating cultures by all of the following except A) limiting access to inside the cabinet. B) maintaining a specific flow of filtered air. C) readily being decontaminated using UV light. D) regular surface cleaning with an antimicrobial solution. E) consistent flame sterilization on the inside surfaces.

C) Transmission electron microscopy

A researcher needs to view the details of the entry of a virus into a host cell. Which of the following microscopic techniques would be most appropriate? A) Bright field light microscopy B) Dark field microscopy C) Transmission electron microscopy D) Scanning electron microscopy E) Fluorescence microscopy

A) There would be no effect on Gram-positive cells, but Gram-negative cells would not be visible.

A student was in a hurry to finish lab and forgot to apply the final counterstain (safranin) during a Gram stain procedure. Which statement below best describes the expected result when the stain is viewed under the microscope? A) There would be no effect on Gram-positive cells, but Gram-negative cells would not be visible. B) There would be no effect on Gram-negative cells, but Gram-positive cells would not be visible. C) Any Gram-negative cells in the stain would appear to be Gram-positive. D) Any Gram-positive cells in the stain would appear to be Gram-negative. E) All cells in the stain would be bright pink.

D) electronics like computer memory.

All of the following are or can be produced by microbes except A) food like chocolate. B) drugs like penicillin. C) consumer products like biodegradable plastics. D) electronics like computer memory. E) biofuels like diesel.

D) 50% different genetic material.

All of the following are reasons to classify a new strain of bacteria except A) mutations. B) gene transfers. C) take up genetic material from their environment. D) 50% different genetic material. E) genetic variant.

C) A variation in size between different colonies on a streak plate indicates that the culture is contaminated.

All of the following correctly describe a bacterial colony except A) All of the cells in a colony presumably arose from a single parent cell and are clones of one another. B) The best way to produce a colony is the streak plate method. C) A variation in size between different colonies on a streak plate indicates that the culture is contaminated. D) A pure culture can be obtained from a mixed culture by isolating bacterial colonies. E) Different species of bacteria will produce distinctive colonies that can aid in identification.

E) Influenza

All of the following may involve biofilms except A) kidney stones. B) inner ear infections. C) atherosclerosis. D) endocarditis. E) Influenza.

D) replacing gloves instead of hand washing when time is short.

Aseptic technique can be used for all of the following except A) preventing healthcare-acquired infections. B) safely studying microbes in the laboratory. C) keeping samples pure for studying. D) replacing gloves instead of hand washing when time is short. E) limiting the spread of diseases.

D) Determining the specific genus and species of the bacterial organism that causes cholera.

For which of the following situations could Koch's Postulates be used? A) Determining that an outbreak of measles in a school could be traced to someone who had recently traveled to an area where measles was endemic. B) Studying the relationship between diet and exercise on rates of heart disease in an elderly population. C) Determining whether a vaccine could prevent the spread of influenza in a population. D) Determining the specific genus and species of the bacterial organism that causes cholera. E) Determining how a breakdown in proper aseptic technique caused an outbreak of C. difficile in a local hospital

D) 4

How many principles are there in Koch's postulates of disease? A) 1 B) 2 C) 3 D) 4 E) 5

B) introduce the bacteria into a new mouse to see if it established the same infection

Robert Koch helped establish the germ theory of disease by discovering that anthrax was caused by a bacterial microorganism. After he isolated and purified the same bacteria from several diseased animals, what would be the next step in order to show that this bacteria caused anthrax? A) perform physiological testing B) introduce the bacteria into a new mouse to see if it established the same infection C) visualize the bacteria with an electron microscope D) culture the bacteria on Petri dishes E) find out if antibiotics treat the diseased animals

A) jumps to a conclusion.

Inference-observation confusion occurs when someone A) jumps to a conclusion. B) cannot understand your accent. C) remembers events wrong. D) lies about what happened. E) incorrectly assesses a patient.

B) biogenesis.

Louis Pasteur's S-necked flask experiment strengthened the theory of A) spontaneous generation. B) biogenesis. C) abiogenesis. D) evolution. E) specific gravity.

E) symbiotic; mutualism

Microbes and humans have evolved a variety of ________ relationships, including ________ where microbes help the host. A) commensal; mutualism B) symbiotic; parasitism C) symbiotic; commensalism D) dynamic; commensalism E) symbiotic; mutualism

D) inducing spontaneous mutations in our genome.

Normal microbiota are responsible for all of the following except A) training our immune system. B) producing vitamins for us. C) helping us digest foods. D) inducing spontaneous mutations in our genome. E) impacting our moods and brain functions.

D) question.

The scientific method starts with a(n) A) hypothesis. B) prediction. C) observation. D) question. E) proposal.

B) domain, kingdom, phylum, class, order, family, genus, species

What is the order of the taxonomic hierarchy from least specific to most specific? A) species, genus, order, family, class, phylum, kingdom, domain B) domain, kingdom, phylum, class, order, family, genus, species C) class, order, phylum, kingdom, domain, genus, family, species D) domain, phylum, order, kingdom, class, family, genus, species E) domain, order, class, kingdom, phylum, species, family, genus

A) planktonic; biofilms

When ________ bacteria attach to a surface and begin to replicate, creating multiple layers, sticky communities called ________ may form. A) planktonic; biofilms B) pathogenic; quorums C) plaque; microbiota D) infectious; flora E) matrix; cavities

A) when the host is weakened

When do opportunistic pathogens tend to cause disease? A) when the host is weakened B) when the host has recently traveled to a remote area C) when the host is young D) when the host is pregnant E) when the host didn't wash with soap

B) Joseph Lister: Developed the first anesthetic solution for use in surgeries

Which of the following individuals does not correctly match with their contribution to microbiology? A) Ignaz Semmelweis: First developed aseptic techniques to decrease mortality rates from childbed fever B) Joseph Lister: Developed the first anesthetic solution for use in surgeries C) Florence Nightingale: Established the use of aseptic techniques in nursing practices D) Robert Koch: Developed criteria for determining the causative agent of an infectious disease E) Louis Pasteur: Showed that biogenesis is responsible for the propagation of life

D) mosquito

Which of the following is not a microorganism? A) bacteria B) archaea C) fungi D) mosquito E) helminth

D) Escherichia coli

Which of the following is the correct way to type a scientific name? A) escherichia coli B) Escherichia Coli C) escherichia coli D) Escherichia coli E) Escherichia coli

E) Nitrogen, sulfur, phosphate, and sometimes iron supplements are added to the spill zone to encourage microbial growth.

Which of the following is true about bioremediation? A) Bioremediation never harms the environment. B) Bioremediation will use genetically-modified organisms to break down the chemicals found in the spill zone. C) The Environmental Protection Agency documents a handful of chemical spills per year in the United States alone. D) Antibiotics are used to seed the spill zone to prevent growth of unwanted microbial species. E) Nitrogen, sulfur, phosphate, and sometimes iron supplements are added to the spill zone to encourage microbial growth.

C) Bright field microscopy is the simplest and most common form of microscopy.

Which of the following statements about bright field microscopy is true? A) Bright field microscopy is great for seeing living samples. B) Dark field, phase contract, and differential interference contract microscopy are better for observing dead samples. C) Bright field microscopy is the simplest and most common form of microscopy. D) Bright field microscopy is able to see specimens without natural coloration. E) Bright field microscopy has the sample appear as a brighter contrasting image on a dark background.

D) Immersion oil has a lower refractive index than the glass slide to help increase sample clarity.

Which of the following statements is false? A) Resolution is the ability to distinguish two distinct points as separate. B) Immersion oil is used to get a better resolution at high-power magnifications. C) Ultimately, the resolving power of bright field microscopes is limited by the wavelength of visible light. D) Immersion oil has a lower refractive index than the glass slide to help increase sample clarity. E) Immersion oil channels as much light as possible up through the objective lens instead of being bent.

C) Immunofluorescence is when fluorochromes bind to a specific target and fluoresce after exposure to UV light.

Which of the following statements is false? A) Scanning electron microscopy provides information about surface structures. B) Transmission electron microscopy provides information about internal structures. C) Immunofluorescence is when fluorochromes bind to a specific target and fluoresce after exposure to UV light. D) Fluorescence microscopy is when fluorochromes stain a sample so it will fluoresce when exposed to UV light. E) Fluorochromes can be natural or synthetic.

A) The decolorizing step is the differentiating step.

Which of the following statements is true about the decolorizing step for the acid-fast stain? A) The decolorizing step is the differentiating step. B) Over-decolorizing can lead to false-positive results. C) Acetone-alcohol solution is the decolorizing agent. D) Because acid-fast bacteria have a waxy cell wall that resists decolorization by the acetonealcohol rinse, they appear a deep blue at the end of the procedure. E) Non-acid-fast bacteria appear bright pink-red at the end of the procedure.

D) Agar is used as a solidifying agent for bacterial culture media.

Which of the following statements is true? A) Media for bacterial growth only comes in a few varieties. B) Picking which type of media format to use depends only on the space available. C) Picking which type of media to use depends on how much money the researcher is willing to spend. D) Agar is used as a solidifying agent for bacterial culture media. E) Scientists were not able to grow bacteria in the lab until the creation of the Petri dish.

D) bacteria

Which of the following type of microbe is always unicellular? A) fungi B) helminths C) protists D) bacteria E) viruses

A) Bacteria reproduce asexually.

Why can't prokaryotic species be defined as a group of similar organisms that could sexually reproduce together? A) Bacteria reproduce asexually. B) Bacteria are all too different to be considered similar. C) The mating rituals of bacteria have not been studied enough. D) They can be. E) We can't see them in enough detail to tell how similar they really are yet.

B) An electron beam has a wavelength of about 1 nm, and resolution improves with smaller wavelengths.

Why do electron microscopes have a better resolution than light microscopes? A) An electron beam has a wavelength of about 800 nm, and resolution improves with larger wavelengths. B) An electron beam has a wavelength of about 1 nm, and resolution improves with smaller wavelengths. C) The lenses used to focus the electron beam are more adjustable than the ones in a light microscope. D) The lenses, knobs, and strength of the electron beam can all be highly controlled, which also explains why electron microscopes are so expensive. E) The additional steps necessary to prepare the sample for viewing provide the improved resolution

C) Laws; theories

________ predict what happens, while ________ explain how and why something occurs. A) Theories; laws B) Hypotheses; conclusions C) Laws; theories D) Observations; hypotheses E) Observations; conclusions

A) Louis Pasteur

________ showed that biogenesis is responsible for the propagation of life. A) Louis Pasteur B) Robert Hooke C) Antonie van Leeuwenhoek D) Joseph Lister E) Carl Linnaeus