Microbiology is the study of microbes. Microbes include
algae, viruses, bacteria, fungi, and protozoa.
Chloe loves cheese and has decided to become a cheesemaker when she gets out of college. Chloe has to take microbiology classes as part of her food science degree because
making cheeses requires bacteria and knowledge of how to culture bacteria.
Using microbes to solve biological problems and to produce large quantities of useful items is known as
Claude's dog is vomiting frequently, so he takes him to the vet. The vet tells Claude that his dog has a parasite problem; specifically, the dog has roundworms that are causing his vomiting. This means
Claude's dog is the host, and the roundworms are parasites.
Edward Jenner was able to vaccinate James Phipps against smallpox by noticing that
milkmaids got cowpox, and being exposed to that virus protected them from the similar smallpox virus.
The death rate of mothers delivering in a Vienna hospital in the 1850s dropped enormously because
Ignaz Semmelweis convinced doctors to wash and treat their hands antiseptically.
The Koch postulates are used to establish that
a specific microorganism may be the cause of a disease under study.
Louis was asked to present a paper on the idea that microbes could develop without any cellular parentage. This idea is called
Pauli has discovered a new species of bacterium. The genus is Streptococcus, and Pauli is allowed to name the species after himself. Thus, the precise name for this species will be
Prokaryotes are distinguished from eukaryotes by the absence of a ___________ in the former.
Celeste has managed to classify her bacteria from domain through species, but she is concerned about the fact that some of her bacteria vary slightly, although not enough to knock them out of the species. These variations were once called
Several different serovars of a single species of bacterium can get past a person's immune system because
1 serovar is different enough from another serovar that immunity to 1 doesn't protect against the other.
Resolution by a light microscope can only go to 1000x, so objects of what size are the smallest to be visible with a light microscope?
Staining of bacteria (such as the Gram stain) serves which of the following purposes?
It provides contrast of the specimen against the light background.
Pierre is having a lot of trouble distinguishing the cell morphology (shape) of his prepared bacterial Gram stain under his light microscope. Pierre's professor suggests he try
using the highest power (oil immersion) objective lens and increasing the light.
Duncan is gathering the materials necessary to stain some microbes. He decides to use a differential stain called a Gram stain. This means
he uses 2 stains: 1 that stains Gram-positive bacteria violet and 1 that stains Gram-negative bacteria red or pink.
In 1 type of electron microscopy, electrons pass through the specimen, but heavy metals pile up around the virus and scatter electrons. This type is known as
transmission electron microscopy (TEM).
Which type of electron microscopy resolves down to the smallest possible micron size?
Transmission electron microscopy (TEM)
Which of the following statements is true?
Water is an example of a polar molecule, whereas oil is an example of a nonpolar molecule.
Yolanda is trying to picture a polar molecule in her head. Which of the following would be the best mental image of this type of molecule?
An image of a magnet with positive and negative ends
Dinah is studying a cell sample, and she notices that the cells within the sample rely on the presence of a particular protein molecule in order to break down nutrients into smaller molecules. This molecule would best be categorized as
One major difference between DNA and RNA is that
RNA is usually single-stranded, whereas DNA is almost always double-stranded.
Lipids are found in the membrane of every cell. These substances
function as a barrier to molecules that want to pass through the membrane.
Using a light microscope, Felix is able to see several shapes of bacteria. He identifies a spherical cell, a rod-shaped cell, and a helical cell. Thus, Felix's slide contains
a coccus, a bacillus, and a spirochete.
There are 2 kinds of clusters of bacilliforms that are not typically seen. They are
staphylobacilli and tetrabacilli.
The cell wall of a bacterium is made up of a substance called peptidoglycan, which
is a multi-layered, cross-linked structural carbohydrate held together by short peptide linkages.
Janae is diagramming a bacterium that has a corkscrew filament coming out of it. She identifies this as the
Which of the following statements is correct concerning viruses?
# All viruses are intracellular parasites. (0 Points)
# All viruses contain a nucleocapsid. (0 Points)
# All viruses contain either DNA or RNA but not both.
The most important advantage of solid media over broth is that it allows
specific colonies to be isolated
All of the following predispose people to opportunistic infection
# genetic defects in immunity. (0 Points)
# immunosuppressive therapy. (0 Points)
All of the following are natural barriers (1st line of defense) to infection
* skin. (
* acidity of the stomach.
Which of the following is spread via aerosols?
# Rabies virus (0 Points)
# Arboviruses (0 Points)
# HSV-2 (0 Points)
What is likely to grow to unusually high levels in the vagina when a woman is taking broad-spectrum antibiotics?
An infected woman is more likely than an infected man to miss recognizing which of the following symptoms?
A disease that is most common in the Ohio-Mississippi River drainage area, is spread from bird droppings, and is diagnosed as a yeast in bronchoalveolar lavage washings is
When bacteria carry out aerobic respiration, the electrons finally travel through the electron transport chain to what component?
When a bacteriophage becomes lysogenic, it
integrates its DNA into the host but does not immediately get replicated.
Which of the following statements concerning the Gram stain is correct?
Bacilli may stain pink or purple.
Which kinds of microbes are observed from healthy human blood when observed in the light microscope?
All kinds except viruses
Which of the following is true concerning the lac operon of E. coli?
When the inducer is bound to the repressor, the operon is active.
Autoclave sterilization is generally achieved at
121oC at 15 pounds of pressure for at least 15 minutes
The greatest number of antibiotic allergic reactions because of widespread use is due to
Which class of antibody has its principal role in secretions outside the body, such as mucous and saliva?
What is the number 1 secondary infectious agent seen in AIDS patients?
Pneumocystis jirovecii (Pneumocystis carinii)
What organism has been associated with diarrhea and transmission on raspberries from Central America?
A red rash that starts on the head and trunk, moves out to the extremities, and lasts 7 days is normally due to
A common surface antigen vaccine produced in yeast cells that is especially important to health care workers today is for
What would we call the process of adapting a virus to carry a toxin gene into a plant pest?
Which of the following is the most important structure related to microbial attachment to cells?
Which of the following is not a gram-negative bug?
*****A. Clostridium perfringens
B. Vibrio cholerae
C. Escherichia coli
D. Bordetella pertussis
Which of the following is true related to endotoxins?
B. Can be linked to Meningococcemia
C. Produced by gram negative microorganisms
D. Can cause fever
Which of the following microorganisms arematched correctly with the appropriate isolation media?
A. Fungi - Sabourand's agar
C. Haemophilus influenzae - Chocolate agar
D. Mycobacterium tuberculosis - Lowenstein-Jensen aga
7. Which of the following diseases and bacteria are matched up correctly?
A. Cellulitis - Pasteurella multocida
B. Tularemia - Francisella tularensis
C. Gastritis - Heliobacter pylori
8. Which of the following diseases and bacteria are matched up correctly?
A. Treponema pallidum - Syphilis
B. Tinea nigra - Cladosporium werneckii
C. Borrelia burgdorferi - Lyme disease
9. Which of the following is true concerning Staphylococcus aureus?
A. S. aureus is related to inflammation.
B. S. aureus can cause pneumonia
C. S. aureus can lead to acute bacterial endocarditis
10. Which of the following signs and symptoms is linked to Haemophilus influenzae?
A. Otitis media
11. The Tsetse fly is a transmission factor for which of the following organisms?
B. Trypanosoma gambiense
13. Chagas' disease is commonly treated with Nifurtimox and is linked to the ____ microorganism.
D. Trypanosoma cruzi
14. Which of the following is fungal related?
A. Cryptococcus neoformans
B. Candida albicans
C. Tinea nigra
17. Which of the following viruses is a double strand linear DNA virus?
18. Which of the following viruses is a single strand linear RNA virus?
20. Which of the following microorganisms has been linked to UTI's?
A. E. coli
Roberto's teacher tells him to think of an individual eukaryotic cell as a city and then to describe each organelle within the cell in terms of what function it carries out in this "city." Using this model, how should Roberto describe the role of the Golgi apparatus?
Roberto should compare the Golgi apparatus to a post office because it packages materials for shipping to other locations.
The function of the endoplasmic reticulum is to
fold and transport proteins within (or perhaps out of) the cell
One main difference between prokaryotes and eukaryotes is that
eukaryotes contain nuclei, and prokaryotes do not.
In which of the following situations would a cell most likely rely on endocytosis?
When the cell encounters a large molecule that it can use as a source of energy
Which of the following statements is true?
Phagocytic cells move via amoeboid motion.
C. Phagocytosis is a form of endocytosis.
D. Some organisms obtain food through the process of phagocytosis.
As soon as the pseudopodium of a phagocytic cell surrounds a target substance,
the cell begins to digest the target substance.
Flagella and cilia are extracellular structures used for motility, and both are made of which type of macromolecule?
Because her cross-sectional analysis of flagella and cilia is inconclusive, Lydia decides to use another method to distinguish between the 2 types of structures, and she asks you for advice. You tell her that 1 quick way to distinguish between the 2 is to look at their
How do symbiotic fungi obtain nutrients?
* Symbiotic fungi obtain nutrients from another living organism and, in doing so, directly benefit the other organism in the relationship.
Alice is growing mold on an old orange. Her professor tells her to view the mold under a microscope and classify it as either septate or aseptate. This means that Alice should pay special attention to which of the following features of the mold?
The presence or absence of cross-walls separating the filamentous that makes up the mold
In what way do yeasts differ from molds?
Yeasts grow as single cells, while molds are multicellular.
Which of the following is a beneficial fungus and why?
Penicillium, because it serves as a source of antibiotics
Septate hyphae are characterized by which of the following features?
he presence of cross-walls between individual cells
The cell walls of most fungi are made out of _________, which can be classified as a _________.
Which of the following statements is true?
B. Boiling kills fungal spores.
C. Some molds have a sexual cycle.
D. Fungi make ergosterol rather than cholesterol.
Deborah is examining an organism under a microscope. Her teacher has told her that the organism is from the kingdom Protista, but she needs to determine what category of protist it is. While examining the organism, Deborah notes that it lacks chloroplasts and travels in a manner that resembles crawling. These findings suggest that Deborah is most likely observing what type of protist?
Imagine that all the phytoplankton in the earth's oceans suddenly died. This situation would most likely trigger which of the following?
A drop in the amount of oxygen found in the earth's atmosphere
In order to classify protozoa, scientists generally consider which of the organisms' structures?
Their motility appendages
Which of the following statements is true?
Sporozoa do not make spores.
B. Ciliated protozoal cells have many cilia that beat coordinately.
C. Amoebas use their pseudopodia to move.
Some protozoa exhibit 2 forms throughout their lifetime: a vegetative, growing form and a dormant form. The 1st of these forms is known as a(n) ________, while the 2nd is known as a ________.
Ben is examining a slime mold under a microscope, and he notices that this organism has formed into a collection of fused cells. How should Ben interpret this observation?
Ben should assume that he is looking at an acellular slime mold because the organism that he is observing clearly exhibits a plasmodium.
The major difference between water molds and slime molds is that
water molds have flagellated reproductive cells.
A disease vector, in biological terms, is
a carrier (living or nonliving) of pathogenic microorganism(s).
Transmission of bacteria can be purely mechanical, such as when
a fly walks on feces and then walks on food.
Joaquin is designing an experiment in which he hopes to study the ways in which mosquitoes transmit disease. Specifically, he plans to insert microbes into several mosquitoes' salivary glands. He then plans to place the mosquitoes into a cage with geckos to see whether they infect the geckos. Joaquin's professor points out a flaw in the experiment, however, which is that
geckos are cold-blooded animals, and mosquitoes feed from warm-blooded animals.
Lice can transmit which of the following diseases?
Trench fever, epidemic typhus, and relapsing fever
Which of the following statements is true?
The crab louse sucks the blood of warm-blooded animals.
C. The crab louse causes a very uncomfortable itch.
D. The crab louse does not carry an infectious microbe.
In biology lab, you are examining various arthropods under magnification. Prior to looking at a sample mite, your instructor tells you that all mites are arachnids. Based on this information, you expect that the sample mite will have how many pairs of legs?
Different ticks can transmit different diseases. Dermacentor andersoni, for instance, transmits
Rickettsia rickettsii, which causes Rocky Mountain spotted fever.
Which of the following statements is true?
Viruses are obligately intracellular parasites and, as such, are considered nonliving.
B. Viruses typically contain 2 to 50 genes.
C. Viruses are incapable of growing outside of a host cell.
Lucilla is trying to distinguish among the viruses she is viewing using an electron microscope. Some of the viruses clearly have a bag-like structure surrounding them, and some do not. How can Lucilla sort these viruses?
Into enveloped viruses and naked (nonenveloped) viruses, respectively
Drew has obtained a clinical specimen of a virus and placed this specimen on human cells in a tissue culture. Drew then watches to see what happens. After some time, he sees aggregates of cells growing in the dish. Based on this observation, Drew knows that his specimen must be a(n)
Which of the following would you most expect to find inside a retrovirus?
Two copies of the RNA genome and a special enzyme called reverse transcriptase
Spongiform encephalopathy occurs in those rare instances in which
a mammal has a brain protein that folds in an unnatural fashion.
David is examining a brain sample taken from a recently deceased heifer. David suspects that the animal died from mad cow disease. Which of the following findings would best support David's suspicions?
The brain sample has an excessive number of holes in it.
Kirby is a behavioral researcher who studies both animals and humans. In which of the following situations would Kirby be most likely to suspect that his research subjects are suffering from scrapie?
Kirby is observing a flock of sheep in England when he notices that some of the sheep are abnormally excitable and tend to rub against tree trunks until they wear through their skin.
Which of the following statements is true?
B. Among the cannibalistic tribes of New Guinea, spongiform encephalopathy has not been observed in tribe members who only come in contact with fully cooked human brains.
C. The damage associated with human spongiform encephalopathy usually requires decades to become apparent.
D. In the past, prions were known as "slow viruses."
The prions associated with transmissible spongiform encephalopathy can be spread via
In recent years, numerous cases of transmissible spongiform encephalopathy occurred in Britain, and most of these cases could be traced to
the consumption of contaminated beef.
Liz is growing a particular type of bacterium in the laboratory. In working with this microorganism, she notes that it will grow as long as it is exposed to oxygen and water; in other words, she does not need to supply the bacterium with supplemental sugars, amino acids, vitamins, or other nutrients. This particular bacterium would therefore best be described as a(n)
Which of the following types of bacteria would you be most likely to find along the edge of the Great Salt Lake?
David is creating a broth in which he hopes to culture bacterial samples. To make his broth, he has mixed together extracts of sheep heart and sheep brain. Despite David's knowledge of the broth's 2 ingredients, he does not know the exact chemical composition of the resulting broth. This means that David's broth should be classified as a(n)
Isolation procedures require the use of solid media because
use of liquid media means that colonies of different types of microorganisms cannot be easily separated, distinguished from one another, and identified (i.e., one cannot obtain pure cultures).
Nancy places a cell into a solution that is 99.5% water. Shortly thereafter, the cell begins to increase in size, swelling until its cytoplasmic membrane eventually bursts open. Which of the following statements best explains why the cell ruptures?
The cell ruptures because water begins to diffuse into the cell at a much faster rate than it diffuses out of the cell. This causes an increase in the hydrostatic pressure within the cell, which in turn causes the cell to swell until it ruptures.
Most of the various microbes that are responsible for human diseases can be classified as
Anthony is growing 2 microbes together in a culture; in addition, he is trying to grow each species of microbe in isolation. During the course of his research, he notices that 1 of the microbial species (which he denotes "Species 1") cannot grow successfully unless it is in the presence of the other species ("Species 2"). However, Species 2's growth and survival appear to be altogether unaffected by the presence or absence of Species 1. Anthony thus concludes that the 2 species have a ________ relationship with each other.
Jordan is hoping to grow bacteria in culture. She begins by using a loop to remove a bacterial sample from a nutrient-rich broth, and she then places the sample in a fresh, agar-filled petri dish. Interestingly, the bacteria do not begin to multiply until they have been in the new petri dish for several hours. Jordan is not surprised by this finding because she knows that bacteria go through a ________ phase when 1st introduced to a new growth medium.
In which of the following situations would a bacterial sample most likely come to the end of its log phase?
When the sample has grown to the point at which the amount of nutrients available to it 1st becomes limited
Justin is attempting to determine the number of bacterial cells in a particular sample. To do so, he removes a portion of the sample, dilutes it, spreads the resulting dilution on a a nutrient medium in a petri dish, and incubates the dish. The next day, he notes that there are 44 distinct colonies growing on the agar. Justin can use this information to determine the total cell count in his original sample only if he also knows
the dilution factor he used when setting up the inoculation of the medium.
When treated with a certain enzyme called a protease, a protein disassociates into its constituent amino acids. In this situation, what type of chemical reaction has occurred?
A catabolic reaction
Enzymes decrease the amount of _________ that is required to link 2 molecules together.
Tina is conducting a chemical reaction in which she joins glucose and fructose to form sucrose. In order for this reaction to occur under standard laboratory conditions, she also adds a substance that permits the reaction to take place at room temperature. In this reaction, fructose would best be classified as a(n)
During the process of glycolysis, a single molecule of glucose is converted into 2 ATP molecules and 2 molecules of
Which of the following pathways involves the process known as oxidative phosphorylation, where ATP is synthesized with the help of electron carriers NADH and FADH2?
The electron transport chain
In her work with a particular species of bacterium, Janelle discovers that this species relies on light as its primary energy source. Based on this discovery, Janelle concludes that the bacterium exhibits which type of metabolism?
Priscilla hopes to observe the process of transcription in a eukaryotic cell. In order to see this process take place, Priscilla should focus her attention on what part of the cell?
Why are operons valuable to bacterial cells?
Operons help ensure that all of the cell products required for a particular purpose are produced at the same time and in the correct amounts.
In prokaryotes, translation begins when
the ribosomal 30S subunit binds near the start site on a molecule of mRNA.
Which of the following statements is true?
Within prokaryotes, RNA synthesis and protein synthesis are both spatially and temporally coupled (i.e., the processes occur at the same time in the same part of the cell).
Frank is conducting a series of experiments in which he hopes to alter the rate at which mRNA is produced within a bacterial cell. Which of the following actions would Frank most likely take in an attempt to speed the rate of mRNA production?
Frank would add more RNA polymerase to the cell.
Which of the following statements accurately describes tRNA?
Each tRNA molecule has 2 binding sites; 1 of these sites binds with a particular amino acid, while the other binds with a specific codon.
The process of translation concludes when
the ribosome reaches a stop codon located on a strand of mRNA.
Which of the following statements is true regarding the bacterial genome?
The bacterial genome is a single circular nucleoid not bound by a nuclear membrane plus a repertoire of small circular plasmids that replicate separately from the nucleoid.
Frederick Griffith is responsible for which of the following scientific breakthroughs?
Discovering the so-called "transforming principle," or the process by which genes can be transferred from 1 bacterial cell to another
How did Oswald Avery determine that DNA served as the genetic substance within cells?
Avery observed that bacterial transformation did not occur when cells were treated with DNase, an enzyme that digests DNA into nucleotide subunits (degradation).
You are interested in determining whether viral DNA or viral protein is propagated within host cells during infection. You have infected a sample of E. coli bacteria with radioactively labeled viruses. The protein portion of each virus is labeled with radioactive sulfur, while the DNA (genome) portion of each virus is labeled with radioactive phosphorus. After infection and subsequent incubation of your mixed sample, you separate the viral and bacterial components of the sample via centrifugation, and you analyze each component for radioactivity. What would you expect to find during your analysis?
Upon analysis, you should find that the radioactive sulfur remains outside the bacterial cell, while the radioactive phosphorus has entered the bacterial cytoplasm.
All of the following statements are false except
the 1st step in replication occurs by an initiation process that is DNA sequence specific.
Douglas is studying the process by which the circular bacterial DNA genome is replicated. During the course of his research, he discovers that the process of replication normally ends when
the 2 replication forks that run along the DNA meet at a point opposite the origin of replication.
Which of the following statements best describes the process of DNA proofreading?
During proofreading, DNA polymerase checks each newly added nucleotide to see whether it is properly base-paired. If not, the polymerase removes the incorrect nucleotide and tries again to add the correct one.
The general objective of _________ is to replace a defective gene with a normal gene that restores normal function.
Imagine you are trying to deliver a normal copy of a particular gene into a cell via transfection. Which of the following types of microorganisms should you use as your vector?
Josh is researching gene expression in a particular type of bacterium. During his research, he discovers that a significant percentage of the bacterium's genes are "turned off" unless certain energy sources are available in the bacterium's environment. Based on this discovery, Josh should classify these genes as
What happens when a repressor protein binds to an operator site within an inducible system?
Transcription ceases because RNA polymerase is unable to bind to the adjacent promoter site.
. _________ systems consist of genes that are normally "turned on" but can be "turned off" when doing so is advantageous to the cell.
In which of the following situations would the aporepressor produced by the trp operon be activated?
When environmental levels of tryptophan are high
Imagine that a molecule of tryptophan binds with its corresponding aporepressor protein. The resulting molecule would properly be classified as an
active repressor complex. .
The lac operon is a(n) ________ system that is involved in the _________ of lactose.
Jermaine is studying a specific biochemical pathway within a fungal cell. He notes that when the end product of this pathway is present in ample amounts, the cell's expression of this pathway is repressed. This phenomenon is known as
Which of the following substances would properly be classified as a protease?
An enzyme that degrades a protein
Karen works in a factory where she is exposed to a number of synthetic chemicals. Eventually, she develops a cancerous tumor because 1 of these chemicals has triggered a mutation in her DNA. This particular mutation would be classified as a(n)
Jay works as a landscaper, and the skin on his face and forearms is exposed to sunlight for multiple hours each day. Over time, some of the skin cells in these parts of Jay's body begin to show signs of DNA irregularities. These irregularities are directly related to sun exposure and can thus be categorized as
. Which of the following mutations would be most potentially harmful to the cell?
A missense point mutation
If the sentence "SAM SET THE CUP FOR TEA" represents a strand of DNA and each word in the sentence represents a codon, which of the following sentences represents a frame-shift deletion?
SAM SET THF ORT EA
Leo is researching a mutation within a cancerous cell, and he has determined that this mutation involves the deletion of only 2 nucleotides. This means that the mutation can be classified as a(n)
In his work with E. coli, Jason has just discovered a mutation that causes the cell's lac promoter to function incorrectly. Although this mutation does not affect the remainder of the genes in the cell's lac operon, it nonetheless renders the cell completely unable to respond to changes in environmental lactose levels. This mutation would best be described as a
In which of the following situations would you use the Ames test?
When you want to determine whether a certain chemical causes mutations
Which of the following statements is true?
Gram-negative bacteria can transmit their genes to Gram-positive bacteria and vice versa.
C. Bacterial gene transfer occurs by 3 known mechanisms.
D. Interspecies gene transfer has been observed in bacteria.
Jane is experimenting with 2 different species of bacteria. Upon observing each type of bacterium under a microscope, she notes that the 1st species appears to produce a pilus while the 2nd does not. Based on this observation, Jane can make which of the following conclusions?
The 1st bacterium can be categorized as an F+ cell.
During standard bacterial conjugation,
the donor cell replicates the F-factor DNA unidirectionally, and this new strand is transferred into the recipient cell via the pilus.
In the laboratory, David notices that a specific gene from the nucleoid (not a separate plasmid) of Bacterium X has successfully been transferred into Bacterium Y. Based on this observation, David would most likely suspect that the gene transfer between these 2 cells has occurred by way of
conjugation with a high frequency of recombination.
Bacterial gene transfer via transduction is only possible
in the presence of a bacterial virus (a bacteriophage).
Johann is analyzing the substances produced by a particular type of phage that has been grown in the presence of a radioactively labeled bacterial sample. During his analysis, Johann notices that the phage produces a number of particles that carry the radioactive marker associated with the bacteria. This finding indicates that these particles can be classified as
In which of the following scenarios does specialized transduction occur?
A phage carries 5 specific genes from 1 bacterium to a 2nd bacterium.
Frederick Griffith's famous experiment with mice and heat-killed bacteria demonstrated which form of bacterial gene transfer?
Your lab partner in biology class asks you what it means when a bacterium is described as "competent." Which of the following choices would be your best response to this question?
"A bacterium is described as competent when it has special transport proteins in its cell membrane that allow the entry of DNA molecules."
Zack is working with several bacterial samples, and he wants to make it such that these samples can engage in conjugation or transduction but not transformation. In order to do this, Zack should apply which of the following substances to his samples?
Which of the following substances would best be classified as a nonspecific disinfecting agent?
Glenn works in a facility that manufactures human vaccines. As part of his job, he is responsible for properly sterilizing all of the vaccines produced in the facility prior to shipment. In this capacity, Glenn most likely uses which of the following sterilization methods?
Which of the following statements is true?
B. Dilution of a disinfecting agent may render the agent ineffective.
C. Some disinfectants will not work properly in acidic environments.
D. A bacteriostatic agent inhibits bacterial growth, but it does not kill all bacterial cells
Deirdre is a chemist, and she has just developed a new disinfecting agent. When testing the effectiveness of this agent, she will most likely compare its effects to those produced by which of the following substances?
Within the United States, the majority of the milk that is sold to consumers is pasteurized. This means that
the milk has been heated to a high enough temperature to kill most vegetative cells.
. Which of the following infections would be classified as a nosocomial disease?
A respiratory infection that an elderly woman acquired from her roommate in the hospital
Helicobacter pylori is somewhat unique among microbes in that it can tolerate
highly acidic environments.
In which of the following environments would you most expect to find microbes that can tolerate extremely high pH levels?
Within the salt flats in the Utah desert
Loren is trying to determine what drug he should prescribe to a patient with a bacterial infection of the small intestine. He has 2 choices: a narrow-spectrum antibiotic or a broad-spectrum antibiotic. Loren eventually decides that he will prescribe the narrow-spectrum antibiotic. Which of the following characteristics of these drugs most likely contributed to Loren's choice?
A narrow-spectrum antibiotic is less likely to wipe out the normal, beneficial flora in the patient's body.
If you created a drug that killed 100% of the pathogenic microbes in an infected patient while having no effect on the patient's body, this drug would exhibit the characteristic known as
Priscilla is working with a particular species of bacterium in vitro, when she notices that the application of penicillin impedes her sample bacteria. Priscilla knows that penicillin has had this effect on her sample cells by
inhibiting the growth of their cell walls.
Which of the following is a possible complication of long-term tetracycline use in children?
Jeff is growing bacteria in vitro. He then removes several cells from his sample, treats the cells with sulfa, and performs a chemical analysis of the treated cells the next day. Jeff expects that this analysis will reveal
lower-than-normal levels of folic acid in the bacteria.
For many years, bacterial resistance to penicillins has been on the rise, and scientists believe 1 reason for this is a result of bacteria acquiring new genes that encode an enzyme called
Which of the following practices can help prevent the spread of antibiotic resistance?
Not giving patients unnecessary antibiotics
You have several tubes of bacteria, and you put various concentrations of the same antibiotic into each of the tubes. In doing so, you are attempting to determine the lowest concentration at which the antibiotic will impede growth of the bacteria (i.e., the minimum inhibitory concentration, or MIC). In this case, you are performing what is known as the
tube dilution test
Mary is studying a pathogen that infects humans. In her research, Mary discovers that this pathogen survives within the body because it has the ability to evade phagocytic cells. This means that the pathogen can be classified as a(n)
Chenda's immune system has been compromised for several months because of ongoing chemotherapy. Suddenly, Chenda becomes extremely ill, and her doctor tells her that she is suffering from an opportunistic infection. This means that Chenda has become ill
from a normally innocuous microbe.
Which of the following statements is true?
B. Most bacteria that we know about are harmless (or beneficial) to humans, rather than pathogenic.
C. Exotoxins are common virulence factors.
D. A toxemic infection spreads via the bloodstream.
Hyaluronidase and various hemolysins are examples of substances that can be classified as
Tyrone is interviewing a patient, and he is trying to determine whether the patient's infection is localized or systemic. Which of the following questions would be most appropriate to ask in this situation?
"Has your infection stayed in 1 location in your body, or does it seem to have spread to more than 1 area?"
Which of the following conditions would be properly classified as a sequelae?
Heart valve damage as a result of strep throat
Which of the following professionals would most likely have the greatest amount of training in the field of epidemiology?
An infection control nurse who works for a local hospital
How do iron-binding proteins help protect the body against infection?
These proteins sequester iron so that microbes cannot use it for nutrition
__________ are small proteins released by infected macrophages, fibroblasts, and T cells to alert neighboring cells
In the classical pathway of the complement system, C1 binds to bacterial-bound antibodies and is followed by the binding and activation of several other components. In order, these components are
C4, C2, C3, and C5.
Pieces of C3 and C5 act as chemotactic factors. In other words, these pieces
attract phagocytic cells to the site of the infection.
Greta's doctor tells her that she appears to be deficient in C3 experience. How does this deficiency affect Greta's complement system?
Because of the deficiency, neither Greta's classical pathway nor her alternative pathway can function.
Which of the following statements istrue?
PMNs live for 1 to 5 days.
B. PMNs account for 55% of all white blood cells.
C. PMNs are also called neutrophils.
D. PMNs have a large reserve pool in the bone marrow that can be rapidly released if necessary.
In which of the following situations would a phagocyte rely on the process of diapedesis?
When attempting to squeeze between the cells that form the walls of a blood vessel during an inflammatory response
Phagocytes do not function well in fluid-filled spaces because
they move by crawling rather than swimming.
Daisy suffers from immune dysfunction. After several rounds of testing, her doctor notices that Daisy's body does not appear to release histamines in adequate amounts. This finding suggests that Daisy's __________ may be functioning abnormally.
Lymphocytes comprise perhaps the most fundamental characteristics of acquired immunity because they
recognize foreign Ags and therefore stimulate immunity.
Which of the following is a chief difference between B lymphocytes and T lymphocytes (in humans)?
B lymphocytes mature in the blood marrow, whereas T lymphocytes mature in the thymus.
When a B cell contacts the specific antigen that binds to its surface antibody, it begins to proliferate and eventually gives rise to both
plasma cells and memory cells.
. Sheila is trying to distinguish among the 5 different classes of antibodies. In order to tell the classes apart, she knows she should focus on which portion of the antibodies?
Their heavy chains
To identify the formation of smaller aggregates with antibodies, a scientist might
precipitate small Ab-Ag complexes from a sample by spinning the sample in a centrifuge.
If you give someone a weakened version of a virus before he or she is exposed to the full-strength virus, you are inducing
artificial active immunity.
Poison ivy dermatitis is a good example of cell-mediated immunity and delayed-type hypersensitivity because it
involves the action of Tc cells and takes several days to develop (upon initial exposure).
Which of the following individuals is most likely suffering from a Type I immunological hypersensitivity reaction?
A woman with severe hay fever
All of the following are autoimmune diseases except
B. rheumatoid arthritis.
C. myasthenia gravis.
Why is Mycobacterium tuberculosis impermeable to Gram staining?
Because of the waxy lipids in its cell envelope
Treatment for tuberculosis usually involves
triple antibiotic therapy for anywhere from 6 months to 2 years.
When examining a patient's throat, Christine notices that the patient's tonsils appear to be covered by a pseudomembrane. Based on this finding, Christine should suspect that the patient may be suffering from
There are multiple species of streptococci and 2 major ways to categorize these bacteria. One method of categorization involves __________, while the other involves __________.
sorting the bacteria based on the C carbohydrates in their cell envelope; sorting the bacteria based on their hemolytic reaction on blood agar
Nancy is a nurse, and she is interviewing a patient who has been admitted to the hospital with signs of rheumatic fever. Given the patient's current symptoms, Nancy should be sure to inquire as to whether the patient recently suffered from which of the following conditions?
haryngitis (strep throat)
Gwen works in a hospital lab, and she is currently analyzing a culture grown from the sputum of a patient who is experiencing difficulty breathing. During her analysis, Gwen notes that the culture contains a high number of Gram-positive cocci that are sensitive to the application of optochin. Based on this finding, Gwen concludes that the patient is likely suffering from
With bacterial meningitis, the causative organisms move
from the patient's throat into his or her spinal column.
Jeanne has just recovered from a brief bout with a particular strain of rhinovirus (common cold). She knows that her immunity to this strain will last
for about 1 year.
Common symptoms of infection with a rhinovirus include
runny nose with headache and sore throat without fever.
Most serovars of adenovirus cause mild disease, but a more severe version is often observed in
Giorgio hopes to develop an anti-influenza medication that works by preventing the virus from breaking down the protective mucus layer that lines the throat. This means that Giorgio's medication will be targeted toward which part of the influenza virus?
The neuraminidase on the viral surface
Which of the following statements is true?
The influenza vaccine has a protection rate of 70% to 80%.
C. The vaccine for influenza has been linked to Guillain-Barré syndrome.
D. The influenza virus predisposes victims to bacterial infections.
Jeremy is a pediatric nurse practitioner. He is currently attempting to diagnose an 8-year-old girl who is covered with a rash of red spots. The girl's rash began about 4 days ago, and it is gradually spreading out to her extremities. When inspecting the rash, Jeremy notes that each red spot has a white center that appears to be filled with salt-like crystals. Based on these findings, Jeremy will most likely suspect that the girl is suffering from which of the following conditions?
Which of the following statements is true?
Shingles is the recurrent form of chicken pox, and both conditions are caused by the same virus.
Which of the following methods would be most effective in preventing the spread of poliovirus?
Boiling water prior to human consumption
Within the United States, endogenous polio has been virtually eliminated thanks to widespread use of the
Salk and Sabin vaccines.
Which of the following fungi causes over 25% of all fungal deaths and is considered 1 of the most pathogenic of the fungi?
Kara is a physician, and she suspects that 1 of her patients is suffering from a fungal infection related to Cryptococcus. Which of the following findings would confirm Kara's initial diagnosis?
The presence of encapsulated yeast that produce urease on a culture of the patient's blood or cerebrospinal fluid
Histoplasma, Blastomyces, and Coccidioides all share which of the following characteristics?
All of these fungi exist as yeast at body temperature and as mold in the environment (i.e., they all are dimorphic).
Which of the following individuals would be most likely to suffer from histoplasmosis?
A person who has recently been exposed to bird droppings and bat guano
When a fungus exhibits thermal dimorphism, this means that it
exists in 2 distinct morphologic forms, with each form occurring at a different temperature range.
Harlan is admitted to the hospital with a suspected case of fungal pneumonia. During his stay in the hospital, Harlan is found to have fungal balls in his lungs and several other body cavities, as well as a fungal infection within his ear. When cultured, this fungus grows into a fuzzy mold. All of these findings suggest that Harlan is most likely infected with which of the following organisms?
Within the United States, aflatoxin levels within grains are monitored by what organization?
The Food and Drug Administration
Pneumocystosis is the most common secondary infection in which of the following groups of patients?
People who are suffering from AIDS
Pneumocystis carinii (now Pneumocystis jiroveci) was classified as a __________ until 1999, when it was reclassified as a __________.
Which of the following symptoms would you most expect to see in a patient with typhoid fever?
Intestinal ulcerations, bloody stool, rose spots, and a stepladder fever
With regard to cholera, which of the following statements is true?
The bacterium associated with cholera can grow freely in water, as well as in humans.
B. People who are suffering from cholera experience massive losses of electrolytes.
D. Cholera has caused several pandemics in the last 200 years.
Duncan is a zoologist who specializes in the study of turtles. In fact, he currently has over 20 species of turtle in his laboratory where he is closely involved in their care and feeding. Because of his work, Duncan is at increased risk for which of the following conditions?
Health workers sometimes say that transmission of coliforms involves the "5 Fs," which are
feces, flies, fingers, food, and fomites.
Infantile diarrhea, traveler's diarrhea, cystitis, and bacteriuria have all been linked to which of the following organisms?
Phillipa is a public health worker who hopes to reduce the rate of campylobacteriosis in a rural South American village. Which of the following measures would Phillipa most likely employ in her efforts toward this goal?
# Production and distribution of educational materials regarding proper techniques for cooking poultry
# Construction of a water purification facility within the village
# Arranging for pasteurization equipment to be delivered to the village
Today, researchers know that the majority of gastric ulcers in humans are associated with
infection with H. pylori.
Bacillary dysentery is different from normal diarrhea in that
it involves the production of bloody, mucus-containing stools, as well as the presence of a greater number of bacilli.
Sandra is a safety inspector at a facility that cans vegetables. One of her responsibilities is to make sure that all cans are properly sterilized so as to remove botulism spores. Sandra know that this requires the factory to
apply 15 pounds of pressure and keep the food at 121°C for a full 15 minutes.
The most common cause of food poisoning is
the enterotoxin secreted by certain strains of staphylococcus.
Viral gastroenteritis has mild symptoms in otherwise healthy adults; however, it can be life-threatening in
malnourished children under the age of 5.
Which of the following individuals would be at greatest risk for hepatitis A?
A person who has recently consumed uncooked shellfish
Which of the following statements is true?
Symptoms of hepatitis A include nausea, vomiting, and fever.
B. The death rate from hepatitis A is about 0.1%.
D. The incubation period for hepatitis A ranges from 2 to 4 weeks.
In what way does the hepatitis B virus differ from other hepatitis viruses?
The hepatitis B virus is a DNA virus, while the other hepatitis viruses are RNA viruses.
In addition to gastroenteritis, which of the following diseases is associated with certain strains of the Coxsackie virus?
Strain B4 of the Coxsackie virus has a strong correlation with diabetes. Researchers believe that this correlation exists because the strain
induces an autoimmune response that destroys the insulin-secreting cells of the pancreas
Jolene is analyzing a viral sample in order to determine what strain makes up the sample. She suspects that the sample contains a type of echovirus, but she knows that this is not the case when she notices that the viruses within the sample
Garnet is a family physician, and she is currently counseling a patient with suspected gastroenteritis. When the patient asks Garnet how long he should expect to experience symptoms, Garnet tells him that his symptoms should resolve within
24 hours or less.
Jasmine is undergoing medical testing to determine what is causing her to experience bloody stools. Interestingly, Jasmine is not suffering from diarrhea. Eventually, numerous ulcers are discovered near the intersection of Jasmine's small and large intestines, along with a multitude of cysts and trophozoites. These findings are most suggestive of which of the following diseases?
Of the following conditions, which is most likely to arise from the consumption of imported produce?
Mark is examining a helminth under a microscope when he notices that the worm exhibits both male and female reproductive organs. The presence of both sets of organs suggests that Mark is most likely looking at a
Which of the following measures would be most effective in the prevention of a tapeworm infection?
Only eating beef and pork that have been thoroughly cooked
Debbie is a school nurse. She notices that a significant percentage of the children in her school suffer from diarrhea accompanied by itchiness in their anal region. Based on these symptoms and her existing knowledge of parasitic infection, Debbie suspects that these children are affected by
Priam is examining a soil sample when he notices some larvae in the sample. He decides to isolate the larvae and watch them develop. Eventually, he notes that the larvae have grown into long, slender roundworms that move by whipping themselves back and forth. Priam's observations suggest that he is working with which of the following species?
With trichinosis, cysts attach not only in a person's intestine, but also in his or her
diaphragm and brain.
In males, symptoms of gonorrhea include
nflammation of the urethra, dysuria, and an inflammatory response.
Why might a nurse put silver nitrate drops in a newborn's eyes immediately following birth?
To protect the infant against neisserial conjunctivitis
Which of the following statements is true?
In approximately 10% of women, gonorrhea progresses to invasive pelvic inflammatory disease.
C. The bacterium that causes gonorrhea is able to attach to the inside of the male urethra, which allows it to overcome the flushing mechanism of urine.
D. Humans are the only reservoir for gonorrhea.
Which of the following symptoms is typical of the 1st stage of syphilis?
Development of a painless ulcer, usually in the genital region
Brett is a physician in a sexual health clinic where he frequently diagnoses patients with syphilis. Upon learning of their diagnosis, many of these patients ask for a prescription for penicillin. Unfortunately, this medication only works in those patients who
are in the 1st or 2nd stages of the disease.
General paresis is characterized by which of the following symptoms?
Emotional instability, memory loss, delusions, and related mental illnesses caused by long-term infection with Treponema pallidum
One of the primary difficulties associated with syphilis research is the fact that
the causative organism is difficult to culture and requires an animal model system
Heather is a gynecologist, and she has the unfortunate task of telling some of her patients that they are suffering from salpingitis. In explaining this condition to affected patients, Heather explains that it is associated with
scarring of the fallopian tubes.
Which of the following statements is true?
B. Genital herpes can be spread even in the absence of lesions.
C. Once a person has contracted genital herpes, he or she can never be fully cured of the condition.
D. It is normally recommended that a mother with active lesions at childbirth have a C-section.
Which of the following patients would most likely benefit from administration of iodoxuridine?
A patient with herpetic keratitis
Most patients with HSV infections are administered _________ to help reduce the severity and length of recurrent infections.
Stacey has just learned that she is infected with the papilloma virus, and she is convinced that she will eventually develop cancer as a result. However, she feels slightly relieved upon learning that
papilloma virus requires a cofactor, such as smoking, to result in cancer development.
Candace is a gynecologist, and she is currently reviewing the lab report regarding the types of microorganisms present in a particular patient's vagina. Upon noting that Candida albicans was among the organisms detected by the lab, Candace
is not concerned because she knows that C. albicans is part of the normal vaginal flora in over 30% of women.
Which of the following factors predispose women to the development of vulvocandidiasis?
Diabetes and pregnancy
"Ping-pong candidiasis" refers to the situation in which
men serve as a source of reinfection for women who keep redeveloping candidiasis after treatment.
Bridget has been taking antibiotics for the past month to help treat an ongoing infection in her leg. Recently, she has begun to experience vaginal burning and itching, which is accompanied by a white discharge. In this situation,
Bridget is likely suffering from a yeast infection because the antibiotics have probably eliminated most of the lactobacilli in her reproductive tract.
Sydney is working in the laboratory to identify the protozoan that causes trichomoniasis. She knows that one marker of this organism is the presence of
an undulating membrane.
Which of the following groups of patients is most likely to experience severe symptoms of trichomoniasis?
Tetanus differs from skin diseases like staph and anthrax in that tetanus
can be prevented with a vaccine.
Margot was admitted to the hospital for a routine tonsillectomy. While in the hospital, she contracted a Staphylococcus aureus infection. Margot's doctors are concerned because her immune system does not recognize the S. aureus bacterium as a foreign body and is making no attempt to fight the infection. The most likely reason for this is the presence of
Why would a doctor administer a coagulase test on a microbial isolate from a patient with a staph infection?
To determine whether the infection is caused by S. aureus or S. epidermidis
What is the most effective method for preventing the spread of anthrax?
Vaccination and treatment of cattle
Anthrax is considered a primary candidate for biological warfare because
of the severity of the infection it causes and the ease of preparing a spore suspension.
Priscilla suffered a leg injury a week ago. At the time, she was able to stop the bleeding on her own and decided not to go to the hospital because her injury was not that painful. However, as the days passed, Priscilla's wound began to putrefy, and blood flow to her leg was eventually cut off. When her leg began to turn a greenish-black, she finally went to the hospital, where she was diagnosed with gas gangrene. What course of treatment is most appropriate for Priscilla at this point?
Amputation of the leg to remove the necrotic tissue
How does E. faecalis most commonly enter the human body?
Through perforation of the intestinal tract
Dwight has a patient with an E. faecalis infection. He has tried giving the patient penicillin, and he will next try methicillin. If that doesn't cure his patient, Dwight's next step should be to try
What led to Edward Jenner's development of the 1st smallpox vaccine?
The observation that milkmaids infected with cowpox were immune to smallpox
hy is there growing concern that smallpox could be successfully used in biological terrorism?
Widespread vaccination for smallpox ended in 1971, so many people are currently susceptible to the disease.
The primary cause of the drop in rabies in humans is
the routine vaccination of domestic dogs and cats.
Trusty is a dog who was recently bitten by a wild raccoon. Trusty was overdue for his rabies booster at the time he was bitten, and his owners fear that he may have contracted rabies from the raccoon bite. If Trusty did contract rabies from the bite, how long will it take for his symptoms to develop?
6 weeks to several months
Thomas is infected with HSV-1. Occasionally, he will have recurrences of symptoms, including cold sores around his mouth. Most of the time, however, the virus is harbored by his body in a dormant form, and Thomas shows no signs of HSV-1 infection. This dormant period between recurrences is referred to as
Randy has a patient with a high fever and roseola. The worst-case scenario for his patient is that she might develop
seizures from infection of nervous system cells.
Which of the following statements best describes the appearance of Kaposi's sarcoma?
Purplish-brown skin discolorations indicate the presence of tumors.
Which of the following individuals is at the greatest risk for infection by dermatophytes?
A student who shares a hair brush after gym class
Marty recently returned home from summer camp. He brought a note with him stating that some campers had developed ringworm infections over the course of the summer and that parents should keep a close eye on their children to ensure that they do not develop ringworm infections, too. What symptoms should Marty's mother watch for as an indicator that he has ringworm?
Round, raised areas of intense itching
Which of the following statements about ringworm infections is true?
B. Dermatophytes grow best in moist, warm environments.
C. Some fungal organisms can last for years in an infected area.
D. Hair or scalp infections are known as tinea capitis.
Candidiasis has different names depending on where it presents initially. When in the mouth, it is called
Colin is trying to determine whether he is working with Candida in his lab. He can confirm that he is indeed working with this organism by
determining whether it ferments carbohydrates using differential tests.
Eli recently suffered a puncture wound on his foot that became infected. His doctor tested him for a variety of things. After receiving lab results indicating the growth of thick, leathery mold in culture, she determined that Eli had contracted sporotrichosis. Eli had never heard of sporotrichosis, knowing it instead by its more common name of
rose thorn disease.
The plague has the nickname Black Death because
victims experience dark purple or black hemorrhages.
Aidan went camping last weekend with some friends, but he forgot to bring along his insect repellent. Since returning home, he has read several reports of tularemia contracted in the area where he was camping. Aidan is worried that he may have been exposed. What symptoms should he watch for as early indicators that he has contracted tularemia?
Skin ulcers at insect bite locations
Epidemic typhus is commonly passed from person to person by
sharing clothing or blankets with an infected person.
Jocelyn was recently admitted to the hospital because her doctor suspects she has Lyme disease. She has not yet manifested any flulike symptoms, and the doctor is still awaiting blood tests to confirm that the causative bacteria are in her bloodstream. However, the presence of erythema chronicum migrans led him to believe that Jocelyn may be infected. Erythema chronicum migrans is
a bull's eye rash around the infection site.
Chloe is treating a patient in stage 3 of Lyme disease. She has to inform her patient that complications can include
arthritis, heart, and nervous system problems.
Which of the following statements about Lyme disease is true?
Lyme disease is rarely lethal but has painful, debilitating consequences for survivor
How do some strains of S. aureus cause infections leading to toxic shock syndrome?
They produce exotoxins after growing on indwelling devices like tampons, catheters, and stitches.
Three common arboviruses in the United States are the St. Louis encephalitis virus, California encephalitis virus, and eastern equine encephalitis virus. Of these 3, the highest mortality rate is associated with the
Eastern equine encephalitis virus.
Which of the following individuals has the greatest risk for contracting hepatitis D?
A patient infected with HBV
What effect does Epstein-Barr virus have on an infected individual's B lymphocytes?
It causes dramatic growth of cytoplasm in B lymphocytes.
Incidence of Epstein-Barr virus is highly concentrated among
individuals who are 16 to 20 years old.
Renee is concerned that her patient, a pregnant woman in her mid-20s, has developed cytomegalovirus. Renee's chief concern is that her patient's
fetus will develop mental damage and loss of hearing.
Simon is an HIV patient who is experiencing cytomegalovirus reactivation. He has not yet experienced any complications from reactivation of the virus. However, Simon's doctor has warned him that many patients in his situation experience
retinitis that often leads to blindness.
Quinn is a zoologist who primarily studies monkeys. She recently spent 3 months in Africa observing a variety of monkeys in their natural habitats. Since her recent return, she has been hospitalized for a high fever and severe ocular and gastrointestinal hemorrhaging. Quinn's doctors are currently awaiting lab results, but, based on her symptoms and recent travels, they believe she is suffering from
Which of the following statements about hemorrhagic fever is true?
In many cases of hemorrhagic fever, internal organs rupture or liquefy.
B. All hemorrhagic fevers are fatal in up to 80% of patients.
C. There are currently no vaccines or treatments for hemorrhagic fever.
The word malaria is derived from
the Italian words for "bad air" because atmospheric miasma was originally believed to be the cause.
How do merozoites evade destruction by the immune system?
They constantly alter the gene used to express their surface protein.
Which of the following statements about malaria is true?
B. Malarial resistance to quinine and chloroquine is becoming commonplace.
C. Death from malaria is the result of anemia, kidney damage, heart attack, or cerebral hemorrhage.
D. The infectious form of malaria is introduced to humans through the saliva of mosquitoes.
Colleen was recently hospitalized as a result of unusual changes in her behavior, particularly her sleep patterns. Her doctors have diagnosed her with trypanosomiasis. What additional symptoms is Colleen likely to experience based on this diagnosis?
Severe headache, chronic bouts of fever, and wasting
Which of the following is a common symptom of toxoplasmosis?
Swollen lymph nodes
B. High fever
Corrine is 19 years old and expecting her 1st child in a couple of months. Her husband is very concerned about her coming in contact with Toxoplasma gondii. As a result, he takes great care to ensure that Corrine is not exposed to potential sources of the disease. What is the most likely reason for his concern?
Unborn fetuses are at high risk for contracting toxoplasmosis.
What does gp160 do after it attaches to a human T cell?
It penetrates the cell, uncoats itself, and releases its viral RNA into the lymphocyte.
Suzanne was recently told by her doctor that she is HIV positive, which most likely means that
HIV is present in her blood but AIDS has not yet developed.
The high incidence of Kaposi's sarcoma in AIDS patients is due to
the reactivation of the human herpes virus 8.
Which of the following statements about HIV/AIDS treatments is true?
Nevirapine works by binding to the reverse transcriptase enzyme.
B. Zidovudine works by modifying the growing DNA.
D. Most HIV treatments involve combination therapy.
Denise is reviewing cells from 1 of her AIDS patients under a microscope, and she sees good news about his CD4 cell counts. It appears that the combination therapy she has prescribed for him has been working because
he has regained CD4 cell counts above 200/mm3.
Combination therapy can prevent _____ of transmission of AIDS from a pregnant woman to her fetus or newborn.
Based on morbidity and mortality, the biggest disease risk for health care professionals today is
Which of the following statements about the difference between food spoilage and fermentation are true?
Spoilage is the result of bacteria that may be harmful to humans and have an undesirable taste. Fermentation is the result of bacteria that aren't harmful to humans and have a desirable taste.
What causes the holes found in Swiss cheese?
he formation of carbon dioxide bubbles during the fermentation process by Propionibacterium
Which of the following statements does accurately describe why industrial microbiology is an economically viable source of organic chemicals?
B. Microbes are easy to manipulate genetically and, as a result, a single microbe can yield numerous products.
C. Microbe metabolism is specific to a microbe's genus and species, and each genus is highly diverse.
D. Microbes can produce desirable products from cheap, easy-to-obtain starting materials
Kyle enjoys deer hunting, and he processes his own meat and hides from the deer he shoots. Right now, he is curing deer meat to make jerky and processing the hide to make a pair of leather gloves. What enzymes should Kyle rely on for these 2 processes?
He should use proteases to tenderize the jerky meat and to remove extra tissue from the hide to make the leather.
Which of the following products does rely on a commercially produced enzyme to ensure proper functioning?
The creamy center of a chocolate
B. A pair of pants made of linen fabric
D. Laundry detergent with stain lifter
Charlotte works for a large cereal manufacturing company. Recently, the company has lost business to competitors that fortify their cereals with vitamins. Charlotte's company does not have the budget to explore chemical production of vitamins, so Charlotte has been tasked with determining which vitamins can quickly and inexpensively be added to her company's product through microbial processes. Charlotte's investigation will likely show that
riboflavin and cyanocobalamine are cost-effective options.
Why is genetic manipulation of Streptomyces bacteria important to the production of medicinal antibiotics?
Controlled mutation of the bacteria increases production and improves the availability of antibiotics to consumers.
__________ is the type of alcohol produced during winemaking through the fermentation of pyruvic acid.
How are yeasts removed from alcohol and wine after the filtration process is complete?
They are removed by filtration or pasteurization or by a combination of the 2 processes.
Which of the following statements describes a disadvantage of using gene cloning to introduce insecticide-producing bacterial strains into commercially valuable plants?
Genetically-modified bacteria do not compete well with wild-type strains once introduced into a field setting.
A pond with a low level of human pathogen pollution would have
few microbes living in it and a low BOD rate.
Lee lives in the country, and he fishes in the stream that runs adjacent to his farm fields. A few months ago, he noticed a lot of algae growing on the water and decided to stop fishing in the stream until the algae disappeared. However, when the algae went away, Lee noticed a lot of fish washing up dead on the banks of the stream. Which of the following statements most likely describes what caused both the disappearance of the algae and the death of the fish in Lee's stream?
The algae died naturally and bacteria living on the dead algae consumed all the oxygen in the water and caused the fish to die.
A marine microbe lives in the warmer, shallower water near the ocean shore. Many other microorganisms live in this same oceanic zone, and quite a few nutrients are found there as well. This microbe lives in the
What purpose does alum serve in the purification of municipal water?
It forms a gelatinous mass that collects microbes as it settles to the bottom of the water.
Why does DDT pose a greater risk to the environment than other commonly used pesticides?
DDT is resistant to microbial breakdown, which leads to high levels of it in the environment.
The bird population of a heavily wooded wildlife preserve was recently hit with a serious fungal infection that caused the death of many of the birds. To help eradicate this infection, the preserve was sprayed many times with a broad-spectrum antifungal agent. This agent eliminated the fungal infection in the bird population but, because of its non-specific nature, killed many other fungi normally found in the preserve. What effect will the death of these fungi likely have on the carbon cycle?
It will decrease the amount of carbon returned to the carbon pool because it will inhibit the degradation of certain components of dead plant matter.
Why is it necessary to convert gaseous nitrogen into nitrates through the process of nitrogen fixation?
Animals and plants both rely on nitrates. Without nitrogen fixation, all available nitrogen in the world would remain in an unusable gaseous form, and life would cease.
The proteins and amino acids that make up nitrogen are broken down into nucleotides in a process known as
the occurrence of lyme disease mainly in areas where certain species of ticks live would define it as a _____ disease
which of the following modes fo action would be most selectively toxic?
preventing cell wall synthesis
why must the lagging strand of DNA be replicated in short pieces?
the DNA polymerase can synthesize in only one direction
the FADH2 formed during the TCA cycle enters the electron transport system at which site?
electron transport/oxidative phosphorylation
H+ and e- are delivered to O2 as the final receptor, H2O is produced, NADH is oxidized, ATP synthase is active
which of the following is involved in quorum sensing?
accumulation of inducer molecules, a certain level of biofilm density, self monitoring
features of the nuclear envelope include
a double membrane structure, pores that allow communication with the cytoplasm
pili are tubular shafts in ______bacteria that serve as a means of _______
gram negative, genetic exchange
which early microbiologist was most responsible for developing sterile laboratory techniques?
when a hypothesis has been thoroughly supported by long term study and data, it is considered
a microscope that has a total magnification of 1500x when using the oil immersion objective has an ocular of what power?
bacteria tend to stain more readily with cationic (positively charged) dyes because bacteria
contain large amounts of acidic substances
which type of medium is used to maintain and preserve specimens before clinical analysis?
type II hypersensitivities are due to
complement induced lysis of cells in the presence of antibodies
in which of these ways is the immune system involved in development of cancer?
failure in immune surveillance
fifty colonies of streptococcus pneumoniae on culture of sputum, blood culture bottle with heavy growth
isolation of two colonies of E. coli on a plate of streaked from the urine sample, a mixture of 80 colonies of various streptococci on a culture from a throat swab
colonies of black bread mold on selective media used to isolate bacteria from stool
in agglutination reactions, the antigen is a _____; in precipitation reactions, it is a ______.
whole cell, soluble molecule
T helper cells receive antigen from ______ and cytotoxic T cells receive antigen from ____.
class II MHC , class I MHC
a monomer, first antibody made during the secondary response, crosses the placenta, fixes complement
a unique characteristic of many isolates of pseudomonas useful in identification is
flourescent green pigment
which of the following represents a major difference between salmonella and shigella infections?
likelihood of septicemia
which of the following are primarily zoonoses
tularemia, salmonellosis, brudellosis, pasteurellosis, bubonic plague
the ___host is where the larvae develops, and the ____ host is where the adults produce fertile eggs.
which of these happens in the case of antigenic shift in influenza A?
recombination of RNA segments between bird and human strains
which of the following conditions is associatied with AIDS?
pneumocystis (carinii) jiroveci pneumonia, kaposis sarcoma, dementia
which of the following is a major subdivision of the biosphere?
hydrosphere, lithosphere, atmosphere
which element has and inorganic reservoir that exists primarily in sedimentary deposits?
phosphorus and sulfur
the floating assemblage of microbes, plants, and animals that drifts on of near the surface of large bodies of water is the ______ community
which of the following bacteria would be the most accurate indicator of fecal contamination?
which gene is incorporated into plasmids to detect recombinant cells?
a gene for antibiotic resistance
which of the following is essential to carry out the polymerase chain reaction?
primers, DNA polymerase, high temperature
which of the following is a part of the sanger method to sequence DNA?
electrophoresis, dideoxy nucleotides, DNA polymerase