Microbiology Final Exam
The characteristics of a pathogen that determine its virulence include which of the following?
1. pathogenicity 2. invasiveness 3. infectivity
The final outcome of most host-parasite relationships depends on
1. the number of organisms present in or on the host 2. the virulence of the organism 3. the host's defenses
A major organism used in the biocontrol of a variety of types of insects is _________.
Bacillus thuringiensis
The nucleic acids carried by viruses usually consist of
Either DNA or RNA
One example of infectious disease transmission by a fomite is
a child developing a cold after playing with a toy that harbored rhinovirus
Sarcinae refers to
a cuboidal packet of cells
In which of the following situations did disease develop due to vertical transmission of the pathogen?
a fetus develops listeriosis after unpasteurized cheese infected with Listeria bacteria is consumed by the mother during pregnancy
All of the following situations are passive modes of penetration for the invasion of host tissues by opportunistic pathogens EXCEPT
a hiker being bitten by a tick
An aquatic microbe that can grow only at the surface of the water is probably which of the following?
a phototroph
Most antibiotics are produced by _________.
actinomycetes
Protists include
algae and protozoa
Diphtheria is treated with
antitoxin and antibiotics
Classification of viruses into families involves determining all the following characteristics except
biochemical reactions
The virus-induced, specific damage to the host cell that can be seen in a light microscope is called
cytopathic effects
Lysozyme is an important antimicrobial substance found at high levels in which food?
eggs
To control pathogenic and disease-causing organisms, spices can be fumigated using _________.
ethylene oxide
The time interval from parent cell to two new daughter cells is called the:
generation time
Corynebacterium glutamicum is used to produce glutamic acid, and this is most successful when the cell permeability is _______.
increased
The first case in an epidemic is called the _________.
index case
Oncogenic viruses include all the following except
measles virus
Which of the following features of a pathogen is not considered to be a virulence factor when establishing infection within host?
pigment production
The exotoxin produced by Corynebacterium diphtheriae
1. causes an inflammatory response 2. causes the formation of pseudomembrane on the respiratory mucosa 3. may destroy cardiac and kidney tissue
Public health surveillance is the proactive evaluation of
1. genetic background 2. environmental conditions 3. human behaviors and lifestyle choices 4. emerging infectious agents
Which of the following must a pathogen possess in order for it to be successful at causing infectious disease?
1. initially be transported to the host 2. be able to exit the host 3. ability to adhere to, colonize or invade the host 4. ability to damage the host
Which of the following does (do) not always require the presence of living bacteria?
1. intoxication 2. food poisoning 3. bacterial diarrhea
Nisin
1. is a small amphiphilic peptide that disrupts membrane integrity and function 2. is a food additive that blocks the growth of some gram positive bacteria 3. is a bacteriocin produced by some strains of Lactocaccus lactis
If a culture starts out with 1 cell and after 4 hours there are 64 cells, how many generations have occurred?
6 generations
A microbiologist inoculates a growth medium with 100 bacterial cells/ml. If the generation time of the species is 1 hour, and there is no lag phase, how long will it be before the culture contains more than 10,000 cells/ml?
7 hours
The size of a eukaryotic cell ribosome is
80S
What is bioprospecting?
An exploration of nature in the search for potentially useful organisms or their products.
Which of the following is the major focus of epidemiologists?
Both the discovery of factors essential to disease occurrence and the development of methods for disease prevention
What is the correct sequence for a Gram stain?
Crystal violet, Gram's iodine, alcohol, safranin
Which of the following statements concerning osmosis is FALSE?
During osmosis, water crosses to the side of the membrane with a lower solute concentration
A patient develops a high fever due to a Gram-negative pathogen. Which of the following is a certain mediator of illness in this case?
Endotoxin
An obligate anaerobe can be cultured in a candle jar. TRUE or FALSE
False
Inanimate materials involved in pathogen transmission are called reservoirs. T and F
False
Surveillance of health issues is typically accomplished by two methods: population surveys and antibiotic treatment. T and F
False
Place the events associated with each stage of infectious disease in the correct order with regard to time.
Incubation, Prodromal, Illness, Convalescence
Two weeks following a hiking trip in which several ticks were noticed and numerous mosquitoes were biting, a 25-year-old man notices a rash shaped like a red ring on the back of his thigh. He was not concerned because he had no other symptoms. Three months later he noticed significant pain in his elbows and his knees. What is the most likely cause of his illness?
Lyme disease
The first person to use heating processes to preserve foods was _________.
Nicholas Appert
The first penicillin-producing fungus that could be grown in stirred fermenters was _________.
Penicillium chrysogenum
The holes in Swiss cheese are produced by the metabolic activities of which bacterial genus?
Propionibacterium
Which of the following is caused by a member of the rickettsias?
Rocky Mountain spotted fever
A selective medium can be formulated either by including inhibitory chemical substances or by leaving out a single crucial nutrient. TRUE or FALSE
True
After an infectious disease has been identified in a population, the next step is to correlate the disease outbreak with a specific organism. T and F
True
Exotoxins can be denatured by iodine to form toxoids which are useful in vaccines. T and F
True
The only organisms to produce endotoxins are Gram-negative bacteria. T and F
True
While exotoxin production is most generally associated with Gram-positive bacteria, some Gramnegative bacteria also produce exotoxins. T and F
True
The ribosomal RNA studies that led to the division of prokaryotic organisms into the Bacteria and the Archaea were begun by
Woese
Corynebacterium glutamicum is used for the large scale industrial production of _________.
amino acids
Which of the following organisms would be most likely to contaminate a jar of pickles?
an acidophile
The sudden increase in the occurrence of a disease above the expected level is called _________.
an epidemic
The condition in the host that results from pathogenic parasitic organism growing and multiplying within or on the host is called
an infection
Phenylacetic acid is added to the penicillin fermentation to allow incorporation of which side chain group?
benzyl
MacConkey agar plates represent __________ medium.
both a differential and a selective
Facultative anaerobes usually possess:
both catalase and superoxide dismutase
The production of natural carbon dioxide by yeasts after a wine is bottled results in ________.
champagne
Organelles found in algae but not found in protozoa or fungi are the
chloroplasts
When a rod shaped bacteria is short and plump, it is called a:
coccobacillus
The core of every virus particle always contains
either DNA or RNA
Organisms that can grow with or without oxygen present are
either facultative anaerobes or aerotolerant anaerobes
In the process of protoplast fusion, cells are grown in a medium that contains
either lysozyme or chitinase, depending on the type of cells
When a disease maintains a relatively steady, low-level frequency at a moderately regular interval, it is called _________.
endemic
Which of the following is not associated with every virus?
envelope
You inoculate a culture into a test tube containing broth and take it out of the incubator the next day. You see the culture is growing equally throughout the broth. You conclude the culture must be:
facultative anaerobe
The term heterotroph refers to an organism that:
gets energy by oxidizing chemical compounds
Endotoxin is released when
gram negative pathogens lyse or divide
Virus morphology does not include which of the following characteristics?
host range
At temperatures higher than the maximum growth temperature for an organism,
hydrogen bonds are broken, proteins are denatured and membranes become too fluid
The term barophile refers to which of the following growth requirements?
hydrostatic pressure
Obligate anaerobes may be cultured in the laboratory
in a reducing medium
When in the human body, Legionella pneumophila resides
in alveolar macrophages
T-even phages
infect Escherichia coli cells
Bacteria of the genus Mycoplasma lack cell walls. What sort of environment do they require for survival?
isotonic
The medium used in protoplast fusion experiments is _________.
isotonic
Lipid A is a component of
lipopolysaccharides
Bacteria with small bunches of flagella emerging from the same site are said to be
lophotrichous
A person who is infected with a potential pathogen fails to develop signs or symptoms of disease. This correlates with _______ initial microbial dose, ___________ microbial lethality and/or ________ replication rate of the pathogen
low, high, low
Which of the following is NOT an example of symbiosis?
microbes passing across the placenta to the fetus
Gamma irradiation has been used to sterilize certain types of foods. There are, however, certain limitations on its effectiveness. One of these is that it will only work on
moist foods
A __________ rate measures the number of individuals who become ill as a result of a specific disease within a susceptible population during a specific time period.
morbidity
The __________ rate is the relationship of the number of deaths from a given disease to the total number of cases of the disease.
mortality
Which of the following is not a characteristic of lipid A?
neurotoxic
The ability of a lens to gather light is referred to as its
numerical aperture
A microbe that grows only at the bottom of a tube of thioglycollate medium is probably a(n)
obligate anaerobe
Vector-borne transmission can be either external or internal. In external (mechanical) transmission, the pathogen is carried
on the body surface of a vector
Which of the following is not a biological effect associated with endotoxin?
paralysis
Which of the following forms of oxygen is detoxified by the enzyme catalase?
peroxide anion
The microscope preferred for viewing living specimens is the ________ microscope
phase-contrast
A cell that uses an organic carbon source and obtains energy from light would be called a
photoheterotroph
Visible, clear, well-defined patches in a monolayer of virus-infected cells in a culture are called
plaques
Viral growth in bird embryos can cause discrete, opaque spots in the embryonic membranes called
pocks
The __________ rate refers to the total number of individuals infected at any one time regardless of when the disease began.
prevalence
Your brother mentions that several days ago he began to feel as if he was coming down with a cold, but now is no longer experiencing any signs or symptoms and feels fine. Having just studied the infectious disease process in your microbiology course, you immediately recognize that he is describing the phase of illness.
prodromal
The process of racking, used in the production of wines, involves
removal of sediments
Organisms that feed on dead organisms for nutrients are called:
saprobes
A chemical that is effective in preserving foods with a low pH such as bread is ________.
sodium propionate
A colony-forming unit is the number of cells
that produces one colony
Mutualism is a relationship
that sometimes provides benefits for both members such that one or both parties cannot live without the other
In microbiology, the term growth usually refers to an increase in
the number of microbial cells
The vector for Rocky Mountain spotted fever is the _________.
tick
Microorganisms require small quantities of this nutrient for enzyme function and maintenance of protein structure:
trace element
In order for a retrovirus to insert itself into the host's DNA, it must do which of the following?
turn RNA to DNA
Host range is limited by
type of host cell receptors on cell membrane
