787 terms

micro test

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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
biotechnology.
Genetic engineering
uses microbes to produce substances like human insulin.
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.
The 1st person to make a microscope and observe "tiny animals" was
Antonie van Leeuwenhoek.
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
spontaneous generation.
The most general (and largest) taxa for microbes is
kingdom
The most specific (and smallest) taxa for microbes is
species
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
Streptococcus pauli.
Biovars vary from one another in terms of
biological properties.
Archaea literally means
"ancient."
Prokaryotes can be divided into what 2 domains?
Bacteria and Archaea
Prokaryotes are distinguished from eukaryotes by the absence of a ___________ in the former.
nucleus
Eukaryotes include everything from
humans to snails to seaweed but not bacteria.
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
strains.
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?
0.1 microns
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.
Electron microscopy involves staining viruses with what?
Heavy metals
Electron microscopy allows us to see viruses that are
0.03-0.3 microns in size.
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)
A medium is a mixture of nutrients that will
support the growth of microbes.
Plastic dishes into which a warm liquid medium can be poured are called
petri dishes.
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
A solution is described as neutral if its pH is equal to
7.
If a material has a high pH number, this means that the material is
a base.
Polymeric molecules have
many copies of a few chemical subunits.
Macromolecules can take the form of
proteins, polysaccharides, nucleic acids, or lipids.
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
an enzyme.
DNA and RNA are
nucleic acids.
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.
Diplobacilli would consist of
2 linked cells that are each rod-shaped.
There are 2 kinds of clusters of bacilliforms that are not typically seen. They are
staphylobacilli and tetrabacilli.
The cell membrane's primary function is to control
what leaves and enters a cell.
The water-like material found inside the plasma membrane of a bacterium is called
the cytoplasm.
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
flagellum.
The function of fimbriae is to
attach to host cells.
Gram-positive and Gram-negative bacteria differ in terms of
their number of cell envelope layers.
Gram's staining involves 2 types of dye and washing the aggregates from the
Gram-negative bacteria.
A bacterial process of recombination that requires cell-to-cell contact is called
conjugation.
Who developed the germ theory of disease?
Koch
Bacterial motility is produced by
flagella.
A bacterium that grows only in the absence of oxygen is a/an
obligate anaerobe.
Rapid growth of bacteria occurs in the
log phase
How do cyanobacteria obtain their energy?
Photosynthesis
Spontaneous changes in genes occur because of
mutagenesis
What component of the bacterial cell wall gives it rigidity?
Peptidoglycan
The most important cellular organelle in the destruction of a pathogen is the
lysosome
All of the following are part of bacterial flagella
# the basal body.
# the flagellin.
# the hook.
Which process produces the greatest amount of ATP?
Electron transport
If a double-stranded DNA virus has a 40% G + C content, how much A will be present?
30%
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 specific characteristic of heterotrophs is that they
obtain carbon from organic compounds
The most important advantage of solid media over broth is that it allows
specific colonies to be isolated
Sterilization indicates
an absence of life
Detergents primarily act on microbes by
dissolving the lipid membranes.
The beta-lactam ring of penicillins is destroyed by
β-lactamase.
An antibiotic reserved for the treatment of tuberculosis is
isoniazid.
The best antiherpes simplex drug is
acyclovir
The antiviral agent that acts to stop uncoating is
amantadine
All of the following predispose people to opportunistic infection
# genetic defects in immunity. (0 Points)
# immunosuppressive therapy. (0 Points)
# malnutrition.
All of the following are natural barriers (1st line of defense) to infection
* skin. (
* saliva.
* acidity of the stomach.
Which of the following is spread via aerosols?
# Rabies virus (0 Points)
# Arboviruses (0 Points)
# HSV-2 (0 Points)
Opsonization is enhanced by
antibodies.
Which of the following is produced by macrophages?
Interleukin 1
What is likely to grow to unusually high levels in the vagina when a woman is taking broad-spectrum antibiotics?
Candida
A source of Legionnaires' disease is
water cooling towers.
Bacteria that have lost the ability to grow on a specific sugar are called
auxotrophs.
Penicillin antibiotic therapy will be most effective against
Streptococcal infections
Mycobacteria are unusually hard for the host to overcome because they
have a waxy cell wall
The principal cell killed by the HIV virus is
T helper or CD4
The varicella-zoster virus is the cause of
chicken pox
Hepatitis B virus
destroys liver cells
Kaposi's sarcoma is associated with infection by the
human immunodeficiency virus.
A virus that contains reverse transcriptase is
human immunodeficiency virus
A protein that causes a given gene or operon to start expressing is called a/an
inducer
Zoonotic transmission is observed for
salmonellosis.
Which of the following diseases is a concern for biological warfare?
Anthrax
An infected woman is more likely than an infected man to miss recognizing which of the following symptoms?
Chancre
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
histoplasmosis.
The feeding form of Giardia lamblia is called a
trophozoite
What do malarial merozoites infect?
Red blood cells
A parasite that is likely to damage the liver and have a life cycle stage in a snail is a
fluke
The agent that causes swimming pool conjunctivitis and keratoconjunctivitis is
adenovirus.
The alcohol in alcoholic beverages is normally produced by
yeast
What organism makes a natural pesticide?
Bacillus thuringiensis
What microbe shells are used to decontaminate water supplies?
Diatoms
Air is forced through sewage to
help aerobic bacteria grow
Actinomycetes as Nocardia and Streptomyces are commonly found in
soil.
A bacterial process of recombination that involves the uptake of free DNA is called
transformation
Staphylococcus aureus causes
food-associated illness (intoxication)
Clostridium perfringens causes
gas gangrene.
Who 1st utilized aseptic technique in hospitals?
Lister
An organism that grows well at 37°C is a/an
mesophile
Preparation for rapid growth occurs in the
lag phase
When bacteria carry out aerobic respiration, the electrons finally travel through the electron transport chain to what component?
Oxygen
Which of the following terms include all fungi?
Molds and yeasts
Which of the following can fix nitrogen?
Cyanobacter
The presence of virus particles in blood is called
viremia
Which of the following does not occur in the infection cycle of all viruses?
Transformation
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.
Mutations are caused by
X rays
Autoclave sterilization is generally achieved at
121oC at 15 pounds of pressure for at least 15 minutes
The best gaseous disinfectant is
ethylene oxide
β-lactamases make bacteria resistant to penicillin by
enzymatically degrading the drug
The greatest number of antibiotic allergic reactions because of widespread use is due to
penicillins
Which of the following is a notably long-lived cell?
Macrophage
Inflammation helps because
increased vascular permeability allows better access for phagocytes.
Which class of antibody has its principal role in secretions outside the body, such as mucous and saliva?
IgA
A viral envelope
is encoded by the host cell's genes
Serology testing refers to
testing blood for antibodies against an infectious agent.
Chemoautotrophs use what for energy?
Minerals in rocks
Scalded skin syndrome is caused by the same agent that causes
boils.
The tine or Mantoux test for TB tests for what type of immune response?
Cell-mediated immunity
Most fungal infections are acquired from
the environment.
Trichomonas vaginalis is a/an
flagellate.
A virus that becomes latent in nerves of the head is
herpes simplex 1.
Genital warts are caused by
papilloma virus.
A severe congenital disease is caused by
rubella
What is the effect of HIV on CD4 cells?
Cell death
Adults visit their doctors the most frequently for
bacteriuria due to E. coli.
How are bubonic and pneumonic plagues transmitted?
Fleas and respiratory aerosols
The great imposter is used to refer to
secondary syphilis.
Hansen's disease decreases ability to sense a touch and is also called
leprosy
Aflatoxins are unusual in that they can cause
liver cancer
What is the number 1 secondary infectious agent seen in AIDS patients?
Pneumocystis jirovecii (Pneumocystis carinii)
What body site renders Plasmodium species resistant to antiparasitic agents?
Liver
What organism has been associated with diarrhea and transmission on raspberries from Central America?
Cyclospora cayetanensis
Perianal itching suggests use of the cellophane tape test to identify
pinworm.
A red rash that starts on the head and trunk, moves out to the extremities, and lasts 7 days is normally due to
measles virus
A common surface antigen vaccine produced in yeast cells that is especially important to health care workers today is for
hepatitis B
Members of Streptomyces are important in the production of
antibiotics.
What would we call the process of adapting a virus to carry a toxin gene into a plant pest?
Genetic engineering
Which ocean zone contains the greatest number of microbes?
Littoral
Using microbes to degrade contamination of the environment is called
bioremediation.
Cellulose, a difficult carbohydrate to degrade, is degraded primarily by
Cytophaga.
Which of the following structures contains genes for enzymes and antibiotic resistance?
A. Plasmid
Which of the following is the most important structure related to microbial attachment to cells?
D. Glycocalix
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 stain well?
A. Escherichia coli
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
B. Pneumonia
D. Epiglottis
11. The Tsetse fly is a transmission factor for which of the following organisms?
B. Trypanosoma gambiense
12. The Ixodes tick is a transmission factor for which of the following organisms?
C. Babesia
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
15. Which of the following is a DNA virus?
A. Adenovirus
C. Papovirus
D. Poxvirus
16. Which of the following is a RNA virus?
A. Reovirus
B. Orthomyxovirus
C. Deltavirus
17. Which of the following viruses is a double strand linear DNA virus?
A. Poxvirus
C. Adenovirus
D. Herpesvirus
18. Which of the following viruses is a single strand linear RNA virus?
A. Togavirus
B. Retrovirus
D. Picornavirus
19. The Tzanck test is used on which of the following viruses?
A. VZV
B. HSV-2
D. HSV-1
20. Which of the following microorganisms has been linked to UTI's?
A. E. coli
B. Pseudomonas
C. Klebsiella
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
In both endocytosis and exocytosis, cells create structures known as
vesicles.
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.
Lysosomes are
digestive organelles filled with a variety of biochemicals and degradative enzymes
Flagella and cilia are extracellular structures used for motility, and both are made of which type of macromolecule?
Protein
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
length.
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.
Heterotrophic organisms are those that
use organic carbon from other organisms.
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
A fuzzy mass of hyphae is called a
mycelium
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
Hyphae are associated with what type of fungus?
Molds
The cell walls of most fungi are made out of _________, which can be classified as a _________.
chitin; polysaccharide
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.
IThe kingdom Protista includes
algae, protozoa, and slime molds.
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?
An amoeba
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
Algal cell walls are usually composed of what substance?
Cellulose
Photosynthesis is an essential process in many protists except
protozoa.
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 ________.
trophozoite; cyst
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.
Which of the following organisms would be classified as arthropods?
Insects and crustaceans
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.
Normally, how many types of microbes can be spread by 1 type of mosquito?
1
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.
Yersinia pestis is the cause of what condition?
Plague
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?
4 pairs
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.
Viruses completely lack which of the following characteristics?
Cellular organelles
All viruses contain
a nucleic acid genome wrapped in a protein coat
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
A viral infection cycle begins with ________ and ends with ________.
attachment; release
How do naked viruses usually release from a cell?
By cell lysis
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)
tumor virus.
A potentially lytic virus is called a
lysogen.
To trick animal cells into uncontrolled cellular growth,
lysogenic viruses require a cofactor.
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
Prions are
the causative agent of mad cow disease and scrapie.
Which of the following statements is true?
Prions are proteins.
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.
In humans, spongiform encephalopathy is known by what 2 names?
Creutzfeldt-Jacob disease or Kuru
Which of the following is a primary symptom of human spongiform encephalopathy?
Shaking
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
contaminated food.
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.
After carbon, the most abundant element in most microbes is
oxygen.
On average, about 70% of a bacterium's weight is made up of
water.
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)
autotroph.
Which of the following types of bacteria would you be most likely to find along the edge of the Great Salt Lake?
Halophiles
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)
complex medium.
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).
Diffusion is driven by which of the following processes?
Brownian motion
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
mesophiles.
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.
commensalistic
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.
lag
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.
activation energy
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)
substrate.
During the process of glycolysis, a single molecule of glucose is converted into 2 ATP molecules and 2 molecules of
pyruvate.
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
Products including yogurt, vinegar, and wine are all a result of the process known as
fermentation
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?
????????????
During the process of transcription,
a DNA template is used to form a molecule of mRNA.
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?
The nucleus
What is a cistron?
A cistron is an individual gene within an operon.
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.
What are the 2 major components of ribosomes?
rRNA and protein
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.
. A ________ is the DNA coding sequence plus upstream control sequences for a single protein.
gene
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.
gene therapy
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?
A virus
In prokaryotes, most gene expression control is seen at the level of
transcription.
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
inducible.
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.
Repressible
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. .
Which of the following is not a protein encoded by the lac operon?
lacO
The lac operon is a(n) ________ system that is involved in the _________ of lactose.
inducible; catabolism
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
feedback inhibition.
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)
induced mutation.
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
spontaneous mutations.
. 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
A nonsense mutation
converts a coding triplet into a stop codon.
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)
frame-shift deletion
An organism's phenotype consists of its
* physical characteristics.
What is an auxotroph?
An auxotroph is a cell that carries a mutation that changes its phenotype.
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
regulatory mutation.
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
transducing particles.
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?
Transformation
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?
DNase
If an object is sterile, you expect it to be
uncontaminated by any life.
Which of the following substances would best be classified as a nonspecific disinfecting agent?
A biocide
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?
Ultrafiltration
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?
Phenol
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
Hand washing is effective at removing __________ organisms.
transient
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
In 1928, penicillin was discovered by which of the following scientists?
Alexander Fleming
The word antibiotic literally translates to
"antilife compound."
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
selective toxicity.
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?
Graying teeth
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
β-lactamase.
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)
extracellular pathogen.
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.
Microbes release endotoxins when
they are damaged or lysed.
Hyaluronidase and various hemolysins are examples of substances that can be classified as
secreted enzymes.
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
Which of the following is true?
The CDC is particularly concerned with communicable diseases.
An epidemic may become a pandemic when
it is spread around the entire world.
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
Interferons
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.
When found within the blood, macrophages are also referred to as
monocytes.
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.
basophils
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.
Which of the following antibodies is associated with allergic reactions?
IgE
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
multiple sclerosis.
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
diphtheria.
Whooping cough in children is caused by which bacterial species?
Bordetella pertussis
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
Group B strep presents the greatest risk to which of the following groups of patients?
Newborns
pyogenes lacks which of the following cellular components?
Outer membrane
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
streptococcal pneumonia.
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
military camps
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?
Rubeola
Which of the following statements is true?
Shingles is the recurrent form of chicken pox, and both conditions are caused by the same virus.
Respiratory syncytial virus gets its name from the tendency of infected cells to
fuse together.
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?
Cryptococcus
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?
Aspergillus fumigatus
Within the United States, aflatoxin levels within grains are monitored by what organization?
The Food and Drug Administration
Phycomycetes species are generally associated with diseases of the
pulmonary system.
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 __________.
protozoan; fungus
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?
Salmonellosis
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?
Escherichia coli
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 is a hallmark symptom of hepatitis?
Jaundice
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?
Aseptic meningitis
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
contain DNA.
Echoviruses can cause a number of diseases, including
gastroenteritis and respiratory infections.
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?
Amoebiasis
Of the following conditions, which is most likely to arise from the consumption of imported produce?
Cyclosporiasis
Balantidiasis differs from all other major human diseases in that it is
caused by ciliates.
Helminths include
both flatworms and roundworms.
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
flatworm.
Tapeworms have many individual segments, each of which functions as a(n)
uterus.
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
pinworms.
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?
Trichuris trichiura
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
Chlamydia is
the most often diagnosed STD in the United States.
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 is the most effective medicine for the treatment of trachoma?
Tetracycline
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.
The organism that causes genital herpes is spread
via direct contact.
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.
acyclovir
Proper condom use reduces the risk of HSV infection by about
tenfold.
All of the following are potential complications of genital herpes except
genital warts.
The Pap smear is the standard test for which of the following conditions?
Cervical carcinoma
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.
The normal treatment for genital warts is
surgical removal of the warts
Which of the following statements is true?
Many people with genital warts are asymptomatic.
Candidiasis is classified as a(n) __________ disease.
fungal
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.
Which of the following protozoans causes trichomoniasis?
Trichomonas vaginalis
_________ is a typical finding in males with trichomoniasis.
Urethritis
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?
Females
Trichomoniasis is mainly transmitted by way of
sexual contact.
Tetanus differs from skin diseases like staph and anthrax in that tetanus
can be prevented with a vaccine.
Which of the following statements about tetanus is true?
It is fatal in 80% to 90% of patients.
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
protein A.
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
Gas gangrene is caused by
C. perfringens.
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
administering vancomycin.
In Europe, smallpox historically had a death rate of
50%.
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
Which of the following viruses causes warts?
The papilloma virus
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
latency.
The gingivostomatitis caused by HSV-1 is a type of
oral lesion.
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 statements best describes mycoses?
They are skin diseases caused by fungi.
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
thrush.
thrush is easily identified by its resemblance to which of the following items?
Milk curds
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.
Which of the following is the most common infectious yeast?
Candida
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.
Which of the following agents is used to treat sporotrichosis?
Potassium iodide
The plague has the nickname Black Death because
victims experience dark purple or black hemorrhages.
How is Yersinia pestis typically transmitted to humans?
Through bites from infected fleas
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
Which of the following bacteria causes Rocky Mountain spotted fever?
Rickettsia rickettsii
Epidemic typhus is commonly passed from person to person by
sharing clothing or blankets with an infected person.
What are the most common animal hosts of Q fever?
Cattle, sheep, and goats
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.
Arboviruses are spread from
birds to humans via mosquito bites.
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.
What route of disease transmission is common to both hepatitis B and hepatitis C?
Blood
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
ebola virus.
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.
Malaria sporozoites become merozoites in the
liver.
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.
Trypanosoma brucei is transmitted by
tsetse flies.
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
Triatomid bugs typically take blood meals from the
lips and face.
Toxoplasmosis is most commonly spread through human contact with
domestic cats.
Which of the following is a common symptom of toxoplasmosis?
Swollen lymph nodes
B. High fever
C. Malaise
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.
A retrovirus is defined by
the presence of reverse transcriptase.
HIV binds to CCR5 coreceptors in order to infect which type of cells?
CD4 lymphocytes
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.
90%
The spread of HIV can be reduced through
abstinence, monogamy, and not recapping needles.
Based on morbidity and mortality, the biggest disease risk for health care professionals today is
hepatitis C.
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.
. Lactic acid is a byproduct of which of the following products?
Cheese
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.
Ethanol
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
littoral zone.
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.
Microbes found in the soil function as a
recycling center for the organic material in the soil.
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
ammonification.
Which of the following id a lymphoid tissue?
spleen, lymph nodes, galt
what is included in galt?
peyer's patches
_______ is an example of an inflammatory mediator that stimulates chemotaxis.
fibrin clot
an example of an exogenous pyrogen is
endotoxin
which of the following is the end product of the complement
membrane attack complex
resident flora is absent from the
lungs
the occurrence of lyme disease mainly in areas where certain species of ticks live would define it as a _____ disease
endemic
which of the following would be a portal of entry?
the placenta, skin, small intestine
which of the following modes fo action would be most selectively toxic?
preventing cell wall synthesis
blocks the attachment of tRNA on the ribosome
tetracycline
interferes with fusion of virus and host cell
amantidine
interferes with synthesis of folic acid
sulfonamides
breaks down cell membrane integrity
poymixin
prevents the ribosome from translocating
erythromycin
blocks synthesis of peptidoglycan
penicillin
inhibition of DNA gyrase
quinolone
microbial control methods that kill ______ are able to sterilize
endospores
the primary mode of action of nonionizing radiation is to
make pyrimidine dimers
______ is the iodine antiseptic of choice for wound treatment
iodophor
a chemical with sporicidal properties is
glutaraldehyde
silver sulfadiazine is used
in antisepsis of burns
which of the following is an approved sterilant?
ethylene oxide
a nucleotide contains which of the following?
5 C sugar, nitrogen base, phosphate
the nitrogen bases in DNA are bonded to the
deoxyribose
the base pairs are held together primarily by
hydrogen bonds
why must the lagging strand of DNA be replicated in short pieces?
the DNA polymerase can synthesize in only one direction
transfer RNA is the molecule that
adapts the genetic code to protein structure
as a general rule, the template strand on DNA will always begin with
TAC
which of these features is found in eucaryotes but not procaryotes?
introns
carries the codon
mRNA
carries the anticodon
tRNA
a process synonymous with mRNA synthesis
transcription
bacteriophages participate in this transfer
transduction
duplication of the DNA molecule
replication
process in which transcribed DNA code is deciphered into a polypeptide
translation
involves plasmids
conjugation, transduction, transformation
many coenzymes are
vitamins
energy is carried from catabolic to anabolic reactions in the form of _____.
high energy ATP bonds
exergonic reactions
release potential energy
a reduced compound is
NADH
most oxidation reactions in microbial bioenergetics involve the
removal of electrons and hydrogens
fermentation of a glucose molecule has the potential to produce a net number of ______ ATP's
2
complete oxidation of glucose in aerobic respiration can yield a net output of _____ ATP
38
the compound that enters the TCA cycle is
acetyl coenzyme A
the FADH2 formed during the TCA cycle enters the electron transport system at which site?
coenzyme Q
ATP synthase complexes can generate ______ ATPs for each NADH that enters electron transport
3
glycolysis
pyruvic aced is formed, fructose diphosphate is split into two 3-carbon fragments
TCA (krebs) cycle
GTP is formed, CO2 is formed
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
the source of the necessary elements of life is
an inorganic environmental reservoir
chemoautotrophs can survive on ________ alone.
minerals and CO2
which of the following statements is true for all organisms?
they require inorganic nutrients
which of the following is involved in quorum sensing?
accumulation of inducer molecules, a certain level of biofilm density, self monitoring
superoxide ion is toxic to strict anaerobes because they lack
dismutase
in a viable plate count, each _____ represents a _______from the sample population.
colony, cell
the envelope of an animal virus is derived from the _______ of its host cell
membrane
a prophage is a _____ stage in the cycle of _______
latent, bacterial viruses
enveloped viruses carry surface receptors called
spikes
viruses cannot be cultivated in
blood agar
clear patches in cell cultures that indicate sites of virus infection are called
plaques
which of these is not a general pattern of virus morphology
complex helical
virus infection
rabies, cold sores, genital warts, mumps, rubella
both flagella and cilia are found primarily in
protozoa
features of the nuclear envelope include
a double membrane structure, pores that allow communication with the cytoplasm
parasitic helminths reproduce with
eggs and sperm
mitochondria likely originated from
purple bacteria
diatom
single celled alga with silica in its cell wall
rhizopus
genus of black bread mold
histoplasma
fungal cause of ohio valley fever
cryptococcus
a yeast that infects the lungs
euglenid
motile flagellated alga with eyespots
dinoflagellate
alga that causes red tides
trichomonas
flagellated protozoan genus that causes and STD
entamoeba
the cause of amebic dysentery
plasmodium
the cause of malaria
enterobius
helminth worm involved in pinworm infection
which structure is not a component of all cells?
cell wall
pili are tubular shafts in ______bacteria that serve as a means of _______
gram negative, genetic exchange
an example of a glycocalyx is
a capsule
which of the following is present in both gram positive and gram negative cell walls?
peptidoglycan
metachromatic granules are concentrated ______ found in ______.
PO4 corynebacterium
the major difference between a spirochete and a spirillum is
the nature of motility
which phylum contains bacteria with a gram positive cell wall?
firmicutes
which early microbiologist was most responsible for developing sterile laboratory techniques?
robert koch
when a hypothesis has been thoroughly supported by long term study and data, it is considered
a theory
resolution is ______ with a longer wavelength of light
worsened
a real image is produced by the
objective
a microscope that has a total magnification of 1500x when using the oil immersion objective has an ocular of what power?
15x
the specimen for and electron microscope is always
killed
motility is best observed with a
hanging drop preparation
bacteria tend to stain more readily with cationic (positively charged) dyes because bacteria
contain large amounts of acidic substances
the primary difference between a TEM and SEM is in
preparation of the specimen
which type of medium is used to maintain and preserve specimens before clinical analysis?
transport medium
hydrogen bonds can form between ________adjacent to each other
a hydrogen atom and an oxygen atom
in a solution of NaCl and water, NaCl is the ______ and water is the _____
solute, solvent
proteins can function as
enzymes, receptors, and antibodies
which allergies are T cell mediated?
type IV
production of IgE and degranulation of mast cells are involved in
anaphylaxis
an example of a type III immune complex disease is
serum sickness
type II hypersensitivities are due to
complement induced lysis of cells in the presence of antibodies
which disease would be most similar to AIDS in its pathology?
DiGeorge syndrome
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
probable infection
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
normal flora
colonies of black bread mold on selective media used to isolate bacteria from stool
environmental contaminant
in agglutination reactions, the antigen is a _____; in precipitation reactions, it is a ______.
whole cell, soluble molecule
which reaction requires complement
hemolysis
the most severe streptococcal diseases are caused by
group A streptococci
_____hemolysis is the partial lysis of red blood cells due to bacterial hemolysins.
Alpha
viridians streptococci commonly cause
subacute endocarditis
which of the following strains of pathogens has the lowest incidence?
VRSA
an important test for identifying Neisseria is
production of oxidase
a complication of genital gonorrhea in both men and women is
infertility
the primary B cell receptor is
IgD
small, simple molecules are _____ antigens
poor
which type of cell actually secretes antibodies?
plasma cell
CD4 cells are ____ cells and CD8 cells are ______ cells
helper, cytotoxic
T helper cells receive antigen from ______ and cytotoxic T cells receive antigen from ____.
class II MHC , class I MHC
Tc cells are important in controlling
virus infections
IgG
a monomer, first antibody made during the secondary response, crosses the placenta, fixes complement
IgA
found in mucous secretions, a dimer
IgD
a monomer, primarily a surace receptor on B cells
IgE
a monomer, involved in allergic reactions
IgM
has greatest number of Fabs, first antibody made during the primary response, fixes complement
a vaccine that contains parts of viruses is called
subunit
widespread immunity that protects the population from the spread of disease is called
herd immunity
most baccillus species are
nonpathogens
clostridium perfringens causes
myonecrosis, food poisoning
the action of tetanus exotoxin is on the
spinal interneurons
the action of botulin is on the
neuromuscular junction
the probable reservoir of listeria is
soil and water
soil mycobacteria can be the cause of
swimming pool granuloma
caseous lesions containing inflammatory white blood cells are
tubercles
which infectious agent is an obligate parasite
mycobacterium leprae
which infection would be catergorized as a zoonosis
anthrax
actinomycetes are ____ that cause _______
filametous rods, chronic granuloma infections
the best therapy for cholera is
oral rehydration therapy
which of the following is an arthropod vector of rickettsioses?
louse, tick, flea
what stage of chlamydia is infectious?
elementary body
ornithosis is a _____ infection associated with _____
chlamydial, birds
mycoplasmas attack the _____ of host cells
ribosomes
necrotizing ulcerative gingivitis is a ____ infection
mixed
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
the bubo of bubonic plague is an
enlarged lymph node
haemophilus influenzae is ________ and requires special ______ for growth
fastidious, blood factors
which of the following are primarily zoonoses
tularemia, salmonellosis, brudellosis, pasteurellosis, bubonic plague
francisella tularensis
rabbit fever
yersinia pestis
bubonic plague
escherichia coli O157:H7
hemolytic uremic syndrome
shigella species
dysentery
salmonella enteritidis
enteric fever
salmonella typhi
typhoid fever
pseudomonas aeruginosa
folliculitis
bordetella pertussis
whooping cough
legionella pneumophila
pontiac fever
haemophilus aegyptius
pinkeye
haemophilus influenzae
meningitis
haemophilus ducreyi
chancroid
pasteurella multocida
local abcess
giardia is a ___ that invades the ______.
flagellate, small intestine
plasmodium reproduces sexually in the ______ and asexually in the _______
mosquito, human
in the exoerythrocytic phase of infection, plasmodium invades the
liver
an oocyst is found in _____, and a pseudocyst is found in _____
feces, tissue
all adult helminths produce
fertilized eggs and larvae
the ___host is where the larvae develops, and the ____ host is where the adults produce fertile eggs.
intermediate, definitive
a host defense that is most active in worm infestations is
eosinophils
currently, the most common nematode infestation worldwide is
ascariasis
trichinosis can only be spread from human to human by
cannibalism
the _____ mosquito feeds on blood, which is required for development of _____
female, eggs
amebic dysentery
entamoeba hisolytica, protozoan, ingestion of food contaminated by human feces
chagas disease
trypanosoma cruzi, protozoan, bite from reduviid bug
tapeworm
taenia saginata, helminth, eating poorly cooked beef or pork
hookworm
necator americanus, helminth
African sleeping sickness
trypanosoma brucei, protozoan
pinworm
enterobius vermicularis, helminth
filariasis
wuchereria bancrofti, helminth, bite from an anopheles mosquito
amebic memingoencephalitis
maegleria fowleri, protozoan
malaria
plasmodium vivax, protozoan
toxoplasmosis
toxoplasma gondii, protozoan, contact with cats or ingesting rare or raw meat
trichinellosis
trichinella spiralis, helminth
whipworm
trichuris trichiura, helminth
river blindness
onchocerca vovulus, helminth, bite from a black fly
cyclosporiasis
ingesting fecally contaminated water of produce
giardiasis
ingestion of cysts in water contaminated by wild animal feces
schistosomiasis
freshwater snail vector releases infectious stage
ascariasis
water or food contaminated with human feces containing eggs
in general, zoonotic viral diseases are ___ in humans
severe, systemic
which virus is used in smallpox vaccination
vaccinia
a virus associated with chronic liver infection and cancer is
hepatitis B
benign epithelial growths on the skin of fingers are called
verrucas
parvoviruses are unique because they contain ____
a single stranded DNA genome
which of the following viruses cause chronic persistent infections?
hepatitis B
which of the following viruses can be oncogenic in humans?
papillomavirus, epstein barr virus
herpes simplex 1
fever blisters, gingivostomatitis
variola
smallpox
polyoma
leukoencephalopathy, cancer
varicella zoster
chickenpox
herpes simplex 2
genital herpes
adenovirus
keratoconjuctivitis
papilloma
condylomata acuminata, cancer
epstein barr
mononucleosis, cancer
cytomegalovirus
mononucleosis
parvovirus
erythema infectiosum
herpes virus 6
roseola
which of these happens in the case of antigenic shift in influenza A?
recombination of RNA segments between bird and human strains
infections with __virus cause the development fo multinucleate giant cells
pneumo
which virus is responsible for korean hemorrhagic fever?
hantavirus
for which disease are active and passive immunization given simultaneously?
rabies
which of the following conditions is associatied with AIDS?
pneumocystis (carinii) jiroveci pneumonia, kaposis sarcoma, dementia
orthomyxovirus
enveloped, single stranded RNA, genome in segments, helical nucleocapsid
rhabdovirus
enveloped, single stranded RNA, helical nucloscapsid
paramyxovirus
enveloped, single stranded RNA, helical nucloscapsid
reovirus
double stranded RNA, genome in segments, icosahedral capsid, nonenveloped
morbillivirus
enveloped, single stranded RNA, helical nucloscapsid
poliovirus
single stranded RNA, icosahedral capsid, nonenveloped
retrovirus
enveloped, single stranded RNA, icosahedral capsid
hantavirus
enveloped, single stranded RNA, genome in segments, helical nucleocapsid
SARS
respiratory tract, respiratory droplets
HIV
brain, WBC, spinal cord, blood transfusion, sexual transmission
mumps virus
parotid gland, kidney, heart; fomites, respiratory droplets
measles virus
brain, respiratory tract; respiratory droplets
hepatitis A virus
intestinal tract, liver; ingestion (oral-fecal)
hantavirus
respiratory tract; respiratory droplets
western equine encephalitis virus
brain, spinal cord; arthrood bite
enterovirus
intestinal tract; ingestion (oral-fecal)
poliovirus
intestinal tract, spinal cord; ingestion (oral-fecal)
rabies virus
brain; respiratory droplets
rubella virus
heart, eye, brain; contact with mammals, respiratory droplets
rotavirus
intestinal tract; fomites, ingestion (oral-fecal)
primary pathogenic fungi differ from opportunistic fungi in being
more virulent
a mycetoma is a
deeply invasive fungal infection of the foot or hand
cocchidioidomycosis
san joaquin valley fever
histoplasmosis
ohio valley fever
blastomycosis
chicago disease
sporotrichosis
rose gardeners disease
paracoccidioidomycosis
south american blastomycosis
dermatophytosis
tinea
candidiasis
yeast infection
which of the following is a major subdivision of the biosphere?
hydrosphere, lithosphere, atmosphere
which of the following is considered a greenhouse gas?
CO2, CH4, N2O
the calvin cycle operates during which part of photosynthesis?
in both light and dark
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
plankton
an oligotrophic ecosystem would be most likely to exist in a
high mountain lake
which of the following bacteria would be the most accurate indicator of fecal contamination?
escherichia
milk is usually pasteurized by`
the high temperature short time method
the dried, prespouted grain that is soaked to activate enzymes for beer is
malt
substances given off by yeasts during fermentation are
alcohol, carbon dioxide, organic acids
which of the following is added to facilitate milk curdling during cheese making?
rennin
secondary metaboiites of microbes are formed during the ______ phase of growth
stationary
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
the function of ligase is to
rejoin segment of DNA
the pathogen of plant roots that is used as a cloning host is
agrobacterium
for which of the following would a nucleic acid probe be used?
locating a gene on a chromosome, developing a southern blot, identifying a microorganism