Which of the following is the BEST description of the field of microbiology?
the study of diseases caused by viruses and bacteria
the study of living organisms too small to be seen without magnification
the study of bacteria
the study of things in the microscope
the study of simple living things
The study of living organisms too small to be seen without magnification
Cells with a relatively simple structure that do not have a true membrane-bound nucleus are referred to as:
Prokaryotes
eukaryotes
urkaryotes
nokaryotes
A and B
Prokaryotes
TRUE or FALSE since viruses are considered to be acellular they are NOT included in any of the domains of life
True - viruses cannot live without a host and acellular means no cell body
Eukaryotic organelles that arose by endosymbiosis include
Lysosomes
the golgi
the ER
Two of these
None of these
None of these (Mitochondria chloroplasts = endosymbiosis)
Which of the following observations by Francesco Redi refutes the idea of spontaneous generation:
Flies laid eggs on uncoverred meat and maggots developed
Covered pieces of meat did not produce maggots spontaneously
maggots and flies are usually associated with meat
all of the above
none of the above
covered pieces of meat did not produce maggots spontaneously
Refute=disproves
Which of the following is NOT one of Koch's Postulates:
The microorganism is present in some healthy individuals and some diseased individuals
The suspected microorganism must be isolated and grown in a pure culture
The same disease must result when the isolated microorganism is inoculated into a healthy host
Actually ALL of these are Koch's Postulates
The microorganism is present in some healthy individuals and some diseased individuals
Why did no bacteria grow in the broth during Pasteur's experiment:
The broth had been frozen before the experiment
He didn't put any bacteria into the broth
the neck of the flask was bent
the temperature was too high for bacteria to grow
the flask was sealed
The neck of the flask was bent
Small internal cell structures are best visualized with a:
Light microscope
dark-field microscope
transmission electron microscope
scanning electron microscope
confocal microscopy
transmission electron microscipe
As the magnification of a series of objective lenses increases the working distance ______:
increases
decreases
stays the same
turns over
cannot be predicted
decreases
TRUE or FALSE the main limitation when using the light microscope is resolution rather than magnification
True (resolution can only down to 200nm)
In the Gram-staining procedure, the primary stain is:
the term used to describe bacteria that have a rod-like shape is
coccus
bacillus
vibrio
coccobacillus
spherillia
bacillus
Bacterial cells of the same species that are variable in shape are called:
vibrio
pleomorphic
coccobacilli
hyphal
mycelium
pleomorphic
Which of the following is NOT a function of the Procaryotic Plasma membrane:
control content
help with energy management
determine and maintain cell shape
provide a selectively permeable barrier
separate the cytoplasm from the outside environment
determine and maintain cell shape
Which of the following is TRUE regarding the periplasmic space:
It is found only in gram-negative bacteia
it is located between the plasma membrane and outer membrane of gram-negative bacteria
it is located between the plasma membrane and outer membrane of gram-positive bacteria
it is larger in gram positive bacteria than it is in gram negative bacteria
TWO of these are TRUE
it is located between the plasma membrane and outer membrane of gram-negative bacteria
What holds the long chains of sugar to each other in Peptidoglycan:
Microfilaments
their amphipathic structure
lipopolysaccharides
Braun's lipoproteins
small polypeptides
small polypeptides
The function of the ribosome in the Bacterial cell is to:
produce energy
tell the cell when glucose is getting more concentrated
replicate DNA
store nutrients
synthesize proteins
synthesize proteins
TRUE or FALSE Gram negative bacteria stain pink because the purple stain cannot get into the cells
False
Bacterial granules that serve as storage locations for organic or inorganic material are called:
Which of the following is NOT an example of a growth factor:
an amino acid which the microbe cannot make
a source of carbon
a vitamin
an enzyme cofactor which the microbe cannot make
a purine or pyrimidine which the cell cannot make
a source of carbon
involves one molecule moving WITH the gradient and another molecule moving AGAINST the gradient:
simple diffusion
facilitated diffusion
primary active transport
secondary active transport
group translocation
secondary active transport (sodium with gradient sugar along for ride against its gradient)
Used for large polar molecules that the microbe wants to come in and they do so by moving from high concentration to low concentration:
simple diffusion
facilitated diffusion
primary active transport
secondary active tranport
group translocation
facilitated diffusion
Microbes in an iron-limited environment will secrete ________ externally to bind ferric iron:
PTS System
calcium
hemoglobin
alkaline phosphatase
siderophores
Siderophores
A complex of nucleic acids and proteins, primarily histones, in the cell nucleus that stains readily with basic dyes and condenses to form chromosomes during cell division.
chromotins
a membrane enclosed structure within a cell, such as a mitochondrion, vacuole, or chloroplast, that performs a specific function.
organelle
a mucopolysaccharide outer shell enveloping certain bacteria
capsule
an organism of microscopic or submicroscopic size, especially a bacterium or protozoan
microorganism
an RNA molecule with catalytic activity
ribozyme
any substance NEEDED for microbial growth
nutrient
culture media that distinguish between groups of microorganisms based on differences in their growth and metabolic products
differential media
dyes that are anionic or have negatively charged groups such as carboxyls
acid dyes
organic compounds that must be supplied in the diet for growth because they cannot be synthesized
growth factors
the characteristic movement of a cell along a chemical concentration gradient either toward or away from the chemical stimulus
chemotaxin
the hypothesis that mitochondria and chloroplasts arose from bacterial endosymbionts of ancestral eukaryotic cells
endosymbiotic hypothesis
the lens in a microscope that first receives light rays from the object and forms the image
objective
the process in which a cell takes up solutes or particles by enclosing them in vesicles pinched off from its plasma membrane
endocytosis
The process in which the internal and external structures of cells and organism are preserved and fixed in position
fixation
The limitation on microbial YIELD (total cells resulting) at high nutrient levels is:
the rate of protein synthesis
the rate of DNA replication
the saturation of the transport proteins for nutrient uptake
the build up of toxic waste molecules
all of the choices
the build up of toxic waste molecules (Yield means the total number of cells at the end)
Binary fission occurs at the maximum rate during the ______ phase:
max
exponential
stationary
death
growth
Exponential
Which of the following is most likely NOT a reason why cells enter stationary phase?
they are running out of an essential nutrient
they are running out of oxygen
the accumulation of toxic waste products
their biochemical reactions are at equilibrium
the population has reached a critical size limit
Their biochemical reactions are at equilibrium
Given a log phase bacterial culture with 10 cells and a generation time of 30 minutes, how many cells will there be in one hour?
100
200
400
800
40
40
Autolysins are involved in?
linking strands of peptidoglycan together
linking peptidoglycan to the plasma membrane
eliminating penicillin molecules
helping penicillin enter the cell
degrading the glycosidic bonds between peptidoglycan molecules
Degrading the glycosidic bonds between peptidoglycan molecules
The penicillin binding proteins:
help the antibiotic enter the cell
link peptidoglycan stands together
help the antibiotic leave the cell
stop the antibiotic from binding the ribosome
two of the above are true
link peptidoglycan strands together
Balanced growth occurs during the _______ phase.
lag
exponential
stationary
death
actually the growth can be balanced in any of these phases
exponential
the process by which all living cells. spores, and acellular entities are either destroyed or removed from an object or habitat is called:
When antiseptics and disinfectants are compared, disinfectants are generally:
less toxic
more toxic
equally as toxic
unpredictable in toxicity
no generalization can be made
more toxic
From the heat killing experiment shown at the right, the D value would be:
time of exposure live cells
1 minute 1,000000.00
2 minute 100000.00
3 minute 10,000.00
4 minute 1,000.00
5 minute 100.00
6 minute 10.00
7 minute 1.0
1,000,000 cells
1 cell
7 minutes
1 minute
zero since we need to kill all the bacteria
1 minute
which of the following influence(s) the efficiency of an antimicrobial agent?
concentration of the agent
duration of the exposure
temperature
all of the choices
only two of the choices
all of the choices
TRUE or FALSE the main reason iodine works so well as an atiseptic is that it is also a strong disinfectant:
true
false
False
(iodine works well as an antiseptic which is why it does not work well as a disinfectant, its not strong enough)
Which of the following metabolic processes can be classified as catabolic:
breaking down glucose to pyruvate
ADP + phosphate = pyruvate
synthesizing proteins from amino acids
a reaction with a positive delta G value
two of the above
breaking down glucose to pyruvate
a reaction that requires an input of energy is ____:
exergonic
spontaneous
anabolic
two of the choices
all three of the choices
anabolic
the synthesis of ATP from ADP and phosphate using the machinery of ATP synthase would include:
photophosphorylation
oxidative phosphorylation
substrate-level phosphorylation
all of the above
two of the above
two of the above
oxidative phosphorylation
substrate-level phosphorylation
if an enzme consists of a protein component and a non-protein component, the non protein component is referred as the:
decreasing the amount of energy released by the reaction
increasing the amount of energy released by the reaction
decreasing the activation energy of the reaction
increasing the activation energy of the reaction
adding energy to the reaction
decreasing the activation energy of the reaction
Which of the following molecules has the greatest ability to accept electrons?
oxygen
nitrate
pyruvate
NADH
Water
Oxygen
Which molecule often links catabolic and anabolic processes in the cell:
pyruvate
nitrate
ATP
Iron
two of these do
ATP
which of the following is TRUE regarding the ATP generated in Glycolysis AND the TCA cycle?
both require high energy electrons
both require the enzyme ATP synthase
Both are examples of substrate-level phosphorylation
tow of these are true
all three of these are true
both are examples of substrate-level phosphorylation
which of the following is NOT produced by glycolysis:
pyruvate
ATP
NADH
carbon dioxide
actually all of these are produced by glycolysis
carbon dioxide
which of the following is NOT produced by the TCA cycle:
co2
GTP
NADH
carbon dioxide
actually, all of these are produced by the TCA cycle
actually all of these are produced by the TCA cycle
(GTP -- form of ATP that is done in TCA cycle)
which products of the TCA cycle transfer electrons to the electron transport chain?
ATP and GTP
FMN and NADPH
oxygen and nitrogen
NADH and NADPH
NADH and FADH2
NADH and FADH2
what causes the rotor of ATP synthase to spin:
PMF
electron motion
ATP formation
NADH oxidation
Oxygen taking electron
PMF
in fermentation the final electron acceptor is:
oxygen
endogenous
exogenous
usually pyruvate
TWO of these
TWO of these
(endogenous, usually pyruvate)
which of the following is TRUE of oxidative phosphorylation?
generates ATP via enzymes in a pathway
uses an endogenous electron acceptor
involves an electron transport chain
two of these are TRUE
all three of these are TRUE
Involves an electron transport chain
TRUE or FALSE Many enzymes catalyzed reactions are freely reversible; however, some key steps require separate enzymes for the reverse reaction in order to provide for independent regulation of anabolic and catabolic pathways
true
which molecule usually acts as an electron donor in biosynthesis reactions?
NADH
NADPH
FMN
Pyruvate
carbon dioxide
NADPH
______ reactions are used to replace TCA cycle intermediates that have been used to provide carbon skeletons for amino acid biosynthesis
which of the following was important for Calvin to determine the pathway of the calvin cycle:
he could purchase CO2 that was labeled with 14C
he could separate molecules with chromatography
he could determine the structure of the separated molecules
all of these were important
Two of these were important
all of these were important
TRUE or FALSE catabolism and anabolism use the same high energy electron activated carriers
true
false
False
which of the following is/are needed for the synthesis of large cellular molecules?
a carbon source
an energy source
an electron source
precursor metabolites
all of these are needed
all of these are needed
a series of chemical reactions that occurs as part of the dark reactions of photosynthesis, in which carbon is broken away from gaseous carbon dioxide and fixed as inorganic carbon in compounds that are ultimately used to make sugars and starch as food
Calvin cycle
an organism that requires a salty environment
halophile
the rotating enzyme complex that couples ATP production to the flow of hydrogen ions
ATP synthase
a series of chemical reactions that occurs as part of the dark reactions of photosynthesis, in which carbon is broken away from gaseous carbon dioxide and fixed as organic carbon in compounds that are ultimately used to make sugars and starch as food
calvin Cycle
inhibiting the growth and reproduction of bacteria
bacteriastatic
an organism, such as bacterium, that can live in the absence of atmospheric oxygen
anaerobe
the plateau of the growth curve after exponential growth, during which cell number remains constant
stationary phase
the material or substance on which an enzyme acts
substrate
a substance that causes or accelerates a chemical reaction without itself being affected
catalyst
making something free of germs as by sterilizing
sanitizing/sanitization
the spontaneous formation of a complex structure from its component molecules without the aid of special enzymes or factors
self assembly
the amount of energy that must be put into a system in order to cause a chemical process to occur
activation energy
a substance that inhibits the growth and reproduction of disease-causing microorganisms
antiseptic
an ATP-generating metabolic process that occurs in nearly all living cells in which glucose in converted in a series of steps to pyruvic acid
glycolysis
What was the conclusion of very's experiment (1944)
That protease destoryed the transforming principle
That lipidase destroyed the transforming principle
That DNAse destroyed the transforming principle
That RNAse destroyed the transforming principle
Two of these are correct
That DNAse destroyed the transforming principle
In Griffith's Transfomration experiment (1928), what became transformed
S-Bacteria were transformed to R-bacteria
Virulent bacteria were transformed to non-virulent bacteria
R-bacteria were transformed to S-bacteria
DNA was transformed to RNA
32P was transformed into 35S
R-Bacteria were transformed to S-bacteria
If DNA froma particular species contains 30% Adenine, how much Guanidine does it contain?
10%
15
20
25%
30%
20%
Transcription produces which of the following
Bi-directional DNA
transfer RNA
Amino acids
Semi-conservative DNA
Proteins
Transfer RNA
Which of the following is TRUE in a DNA double helix
the two DNA strands are complementary
Purines pair with purines
Thymine pairs with cytosine
the sugars in the backbone are ribose
Two of these are TRUE
The two DNA strands are complementary
The fact that replication forks each contain a leading and a lagging strands means that DNA replication is
The region of DNA at which RNA polymerase binds to start transcription is the
Leader
Promoter
coding
activator binding site
origin
Promoter
Which of the following is NOT TRUE of RNA molecules
The molecules are single-stranded
Nucleotides include adenine, guanine, cytosine, and uracil
The sugar found in the neucleotides is ribose
They are very stable and last a long time
actually all of these are TRUE
They are very stable and last a long time
The genetic code is said to be _____ because more than one codon can specify an amino acid
ambiguous
degenerate
multiplicative
specific
universal
degenerate
_______ molecules code for proteins
tRNA
mRNA
rRNA
all of these
two of these
mRNA
Which tRNA binding site is the entry point for tRNAs in the ribosome
the A site
the P site
the E site
the I site
the RF site
the A site
(P is protein site, E is exit site)
TRUE or FALSE the stop codons do not specify amino acids but the start codon does
True
Which of the following is TRUE regarding bacterial transcription
RNA polymerase binds to the promoter and waits for sigma factor to start transcribing
Sigma factor binds to the promoter and waits for the polymerase to start transcribing
Sigma factor must be released to ener elongation
RNA polymerase starts from a primer made by the primase
RNA polymease binds to DNA only with sigma factor
Sigma factor must be released to enter elongation (what RNA polymerasse does - transcribing) sigma factor is first
THe main reason why DNA replication has to be asymmetrical is that
DNA polymerase proofreads
DNA polymerase is a 3' to 5' nucleotide polymerase
DNA polymerase requires a primer
DNA polymerase uses the 3' hydroxyl group from the nucleotide just added
two of these are correct
DNA polymerase used the 3' hydroxyl group from the nucleotide just added (asymmetrical = leading strand lagging strand)
During replication the 2 strands of the DNA molecule are unwound from one another by enzymes called
The strand of DNA double helix from which RNA polymerase reads is called the
transcription strand
sense strand
translation strand
template strand
copy strand
template strand
TRUE or FALSE both the Lac and Trp operons are under negative control
True ( Lac is inducable and Trp is repressible)
When bound to the DNA the repressor protein usually prevents attachment of the RNA polymerase to the
operon
operator
promoter
regulator
activiator
promoter (key word is repressor)
----promoter-----operator----Gene A----Gene B
This presents a particular situation for gene control choose the answer from below:
negative transcriptional control
positive transcriptional control
inducible gene
repressible gene
TWO of the above
Negative transcriptional control
An activator protein that cannot bind to the activator binding site if a particular substance is present in the bacterial cell
negative transcriptional control
positive transcriptional control
inducible gene
repressible gene
TWO of the above
TWO of the above
positive transcriptional control
repressible gene
The presence of a particular substance in the bacterial cell causes an operon to be transcribed
negative transcriptional control
positive transcriptional control
inducible gene
repressible gene
TWO of the above
inducible gene
The tryptophan operon co-repressor _______
is an allosteric protein
is a DNA sequence
is required for production of the mRNA encoded by the tryptophan operon
is important for the production of the tryptophan repressor
is tryptophan
is tryptophan
Thymine Dimers are fixed by
base excision repair
nucleotide excision repair
mismatch repair
proofreading
actually, they aren't fixed
nucleotide excision repair
Mutations allowing for substitution of one purine for another or one pyrimidine for another is called a
Produce their own lysine, and can only grow on media without lysine
produce their own lysine, and can only gow onmedia with lysine added
shut off the Lys operon instead of turning it on
are unable to produce lysine, and can only grow on media without lysine
are unable to produce lysine, and can only grow on media with lysine added
are unable to produce lysine and can only grow on media with lysine added
complementary DNA (cDNA) molecules are produced using
restriction endonucleases
RNA polymerase
DNA ligase
Reverse transcriptase
RNA polymerase
reverse transcriptase
A DNA molecule used to carry a foreign gene into a host organism is called a
plasmid
vector
probe
blot
phage
vector
which of the following best describes the basis for separation of DNA fragments during agarose gel electrophoresis
the fragments with the highest percentage of G and C will migrate fastest
the fragments with the highest percentage of A and T will migrate fastest
the largest fragments will migrate fastest
the smallest fragments will migrate fastest
small and large fragment will migrate at equal rates
the smallest fragments will migrate fastest
the purpose of the southern blotting technique is to
amplify fragments of DNA
cleave DNA into small fragments
construct a plasmid vector
detect specific DNA fragments from a mixture of DNA molecules
replace defective genes with genes that work better
detect specific DNA fragments from a mixture of DNA molecules
in the polymerase chain reaction (PCR), each cycle increases the DNA copy number
Linearly
exponentially
randomly
the copy number remains the same
the copy number decreases over time
exponentially
a mode of gene transfer in prokaryotes in which a piece of free DNA is taken up by a cell and integrated into the its genome
transformation
a polymerase that catalyzed the synthesis of RNA from a DNA template
RNA polymerase
an enzyme that joins two DNA fragments together through the formation of a new phosphodiester bond
DNA ligase
class of RNA molecules that transport amino acids to ribosomes for incorporation into a polypeptide undergoing syntheses
tRNA
the newly synthesized DNA strand that is oriented away from the replication fork and is made in small fragments that are later joined together
lagging strand
the process by which the genetic message carried by mRNA directs the synthesis of polypeptides with the aid of ribosomes and other cell constituents
translation
the RNA that is the structural and catalytic part of a ribosome
rRNA
a mechanism for the the regulation of transcription of some bacterial operons by aminoacyl-tRNAs
attenuation
the segment of DNA to which the repressor protein binds; it controls the expression of the genes adjacent to it
operator
a permanent heritable change in the genetic material
mutation
the typical form of an organism, strain, gene, or characteristic as it occurs in nature
wile type
a short labeled nucleic acid segment complementary in base sequence to part of another nucleic acid, which is used to identify or isolate the particular nucleic acid from a mixture through its ability to bind specifically with the target nucleic acid
probe
enzymes produced by host cells that cleave virus DNA at specific points and thus protect the cell from virus infection; they are used in carrying out genetic engineering
Restriction enzyme
to make identical copies of a DNA sequence
clone
In which way are viruses like LIVING organisms
they evolve
they consist of cells
they have their own metabolism
they multiply on their own
none of these
they evolve
TRUE or FALSE bacteriophages grown on a lawn of bacteria form individual colonies which can be counted to determine how many viruses are in the culture
false
viral spike proteins are involved in
replication
lysis
attachment
lysogeny
all of these
attachment
bacteriophages that can exhibit lysogenic cycles are called _____
TRUE or FALSE the baltimore system classifies viruses primarily on size and capsid symmetry
False
(capsid symmetry - way it looks)
A _______ infection is one in which the virus quits reproducing and remains dormant for a period before becoming active again
persistant
latent
slow virus
lytic
productive
latent
attachment of the HIV virus to its host cell requires
specific surface proteins on the HIV virus
specific receptor molecules on the host cell
nucleic acid and protein interactions
specific surface proteins on the HIV virus and specific receptor molecules on the host cell
reverse transcriptase
specific surface proteins on the HIV virus and specific receptor molecules on the host cell
which of the following MUST carry an RNA-dependant RNA-polymerase in teh neucleocapsid
double-stranded RNA viruses
double-stranded DNA viruses
negative-strand RNA viruses
all of the above
two of the above
two of the above
which of the following would not necessarily be needed to complete the life cycle of an RNA virus
RNA-dependant RNA-polymerase
DNA-dependant RNA polymerase
ribosomes
Self Assembly
all of these are necessary
DNA-dependant RNA polymerase
Which of the following is used to help protect the lungs from infection
turbulent airflow deposits airborne pathogens on sticky mucosal surfaces
the mucociliary escalator moves trapped organisms away from the lungs by ciliary action
coughing and sneezing forcefully expel organisms away from the lungs
all of the choices
two of the choices
All of the choices
Phagocytic leukocytes that circulate in the blood and migrate to sites of infection are called
esonophils
neutrophils
T-cells
B-cells
basophils
neutrophils
_________ is a process by which microorganisms or othr particles are coated by serum components, preparing them for recognition and ingestion by phagocytic cells
A fever enhances the nonspecific immune response by
stimulating leukocytes to destroy microbes
enhancing specific activity of the immune system
decreasing the amount of iron available to microbes
enhancing biostasis
All of these
Blood cell development occurs in the bone marrow of mammals during the process of
pathogen associated molecular patterns (PAMPs) include
lipopolysaccharide
peptidoglycan
phospholipids
all of the choices
two of the choices
two of the choices
which type of immunity is the result of an individual developing his or her own immune response to a microbial infection
artificially acquired active immunity
artificially acquired passive immunity
naturally acquired artificial immunity
naturally acquired passive immunity
naturally acquired active immunity
naturally acquired active immunity
circulating immunoglobulins are part of
the complement system
cellular immunity
humoral immunity
innate immunity
none of these
humoral immunity
(immunoglobulins are antibodies)
T-cells attack
host cells that have been parasitized by microorganisms
transplanted tissue cells from one host to another
cancer cells
macrophages that have become infected
all of the choices
all of the choices
B cells that are actively producing antibodies are called
Class I major histocompatibility complex molecules are are found on
skin cells
antigen-presenting cells
muscle cells
all of the above
two of the above
all of the above
The humoral immune response differs from the cell-mediated immune response in that only in the humoral immune response is there
secretion of antibody
a mature lymphocyte
a clonal selection mechanism
the development of memory cells
actually, all of these are only found in the humoral immune response
secretion of antibody (cytokines being released)
humoral immune (B cells) sends things out to float around (communicator); sends out cytokines (released when virus comes in to the body) goes to neighbor cells on alert for virus
T lymphocytes are cell mediated response - has to actually attach to antigen with attach MHC
which of the following is a characteristic associated with secondary antibody responses
shorter lag phase
lower antibody amount produced
lower antibody afinity
all of the choices
two of the above choices
shorter lag phase
an individual with O blood type can safely receive blood from which of the following donors
Type O donor
type A donor
Type B donor
Type AB donor
All of the above
Type O Donor (universal; have zero)
TRUE or FALSE all the antibodies released from a particular B Lymphocyte will have the same antigen
true (clone-just making copies of itself so same)
The protein shell that surrounds a virus particle
capsid
The process by which an antigen selexts the best fitting B-cell receoptor, activating that B cell, resulting in the synthesis of antibody and clonal expansion
clonal selection
of viruses with RNS genomes that carry the enyzme reverse transcriptase and form a DNA copy of their genome during their life cycle
retro virus
of or relating to an immune response by the body against one of its own cells or tissues
auto immunity
immunity resulting from a cell-mediated immune response allso called Cell-mediated immunity
cellular immunity
any of several regulatory proteins, such as the interleukins and lymphokines, that are released by cells of the immune system and act as intercellular mediators in teh generation of an immune response
cytokine
an infectious agent consisting only of protein
prion
an area of the antigen molecule that stimulates the production of, and combines with, specific antibodies; also known as the antigenic determinant site
epitope
a group of plasma proteins that plays a major role in an animal's defense immune response
complement antibody
a gene whose activity is associated with conversion of normal cells to cancer cells
oncogene
a foreign (nonself) substance to which lymphocytes respond
antigen
a double-stranded nucleic acid that is formed from a single-stranded viral genome and used to synthesize new copies of the genome
replicative form
a complete virus particle that represents the extracellular phase of the virus life cycle
virion
a clear, often round patch of lysed cells in an otherwise opaque layer of a bacteria or cell culture