| Question | Answer |
| How do all viruses differ from bacteria?
Viruses are not composed of cells.
Viruses are filterable.
Viruses are obligate intracellular parasites.
Viruses do not have any nucleic acid.
Viruses do not reproduce. | Viruses are not composed of cells. |
| A feature that may be found in viruses but never in bacteria is
an ability to infect more than one type of host.
they cannot reproduce themselves outside a host.
the ability to pass through 0.22 micrometer pore filters.
may contain an RNA | may contain an RNA genome. |
| Which of the following statements about viral spikes is FALSE?
They may cause hemagglutination.
They bind to receptors on the host cell surface.
They are found only on nonenveloped viruses.
They are used for attachment.
They are compo | They are found only on nonenveloped viruses. |
| Which of the following is NOT used as a criterion to classify viruses?
biochemical tests
size
morphology
nucleic acid
number of capsomeres | biochemical tests |
| Which of the following is NOT utilized to culture viruses?
embryonated eggs
animal cell cultures
laboratory animals
culture media
bacterial cultures | culture media |
| Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps?
release
uncoating
penetration
attachment
biosynthesis | biosynthesis |
| The definition of lysogeny is
when the burst time takes an unusually long time.
attachment of a phage to a cell.
phage DNA is incorporated into host cell DNA.
lysis of the host cell due to a phage.
the period during replication when v | phage DNA is incorporated into host cell DNA. |
| A viroid is a(n)
infectious protein.
provirus.
capsid without nucleic acid.
complete, infectious virus particle.
infectious piece of RNA without a capsid. | infectious piece of RNA without a capsid. |
| Figure 13.1
In Figure 13.1, which structure is a complex virus?
a
b
c
d
All of the structures are complex viruses. | b |
| The morphological types of viruses illustrated in Figure 13.1 are ultimately determined by the | nucleic acid. |
| A clear area against a confluent "lawn" of bacteria is called a
rash.
cell lysis.
plaque.
pock.
phage. | plaque. |
| Continuous cell lines differ from primary cell lines in that
continuous cell lines always have to be re-isolated from animal tissues.
viruses can be grown in continuous cell lines.
continuous cell lines can be maintained through an indefini | continuous cell lines can be maintained through an indefinite number of generations. |
| Which of the following is necessary for replication of a prion?
lysozyme
DNA polymerase
DNA
PrPSc
RNA | PrPSc |
| A persistent infection is one in which
host cells are transformed.
host cells are gradually lysed.
the virus remains in equilibrium with the host without causing a disease.
the disease process occurs gradually over a long period.
vi | the disease process occurs gradually over a long period. |
| An example of a persistent viral infection is
Varicellavirus infection.
Influenza.
Herpes Simplex Virus infection.
Hepatitis A infection.
Human Immunodeficiency Virus infection. | Varicellavirus infection. |
| Lysogeny can result in all of the following EXCEPT
immunity to reinfection by the same phage.
immunity to reinfection by any phage.
acquisition of new characteristics by the host cell.
specialized transduction.
phage conversion. | immunity to reinfection by any phage. |
| Which of the following would be the first step in biosynthesis of a virus with a - (minus) strand of RNA?
synthesis of double-stranded RNA from a DNA template
transcription of mRNA from DNA
synthesis of double-stranded RNA from an RNA templ | synthesis of double-stranded RNA from an RNA template |
| An infectious protein is a
retrovirus.
viroid.
papovavirus.
prion.
bacteriophage. | prion. |
| An envelope is acquired during which of the following steps?
biosynthesis
release
adsorption
penetration
uncoating | release |
| Which of the following statements is NOT true of lysogeny?
Lytic cycle may follow lysogeny.
Prophage is inserted into the host genome.
It causes lysis of host cells.
It can give infected pathogens the genetic information for toxin product | It causes lysis of host cells. |
| An example of a latent viral infection is
subacute sclerosing panencephalitis.
cold sores.
smallpox.
influenza.
mumps. | cold sores. |
| A virus's ability to infect an animal cell depends primarily upon the
host cell's ability to phagocytize viral particles.
enzymatic activity of a host cell.
type of viral nucleic acid.
presence of receptor sites on the cell membrane.
p | presence of receptor sites on the cell membrane. |
| Assume you have isolated an unknown virus. This virus has a single, positive sense strand of RNA, and possesses an envelope. To which group does it most likely belong?
herpesvirus
retrovirus
togavirus
picornavirus
papovavirus | togavirus |
| The mechanism whereby an enveloped virus leaves a host cell is called
abduction.
penetration.
lysogeny.
transduction.
budding. | budding. |
| The most conclusive evidence that viruses cause cancers was provided by
finding oncogenes in viruses.
cancer that developed in chickens following injection of cell-free filtrates.
treating cancer with antibodies. | cancer that developed in chickens following injection of cell-free filtrates. |
| Bacteriophages derive all of the following from the host cell EXCEPT
ATP.
amino acids.
nucleotides.
lysozyme.
tRNA. | lysozyme. |
| Bacteriophage replication differs from animal virus replication because only bacteriophage replication involves
injection of naked nucleic acid into the host cell.
assembly of viral components.
lysis of the host cell. | injection of naked nucleic acid into the host cell. |
| Generally, in an infection caused by a DNA-containing virus, the host animal cell supplies all of the following EXCEPT
tRNA.
RNA polymerase.
nucleotides.
DNA polymerase. | DNA polymerase. |
| Which of the following places these items in the correct order for DNA-virus replication?
1. Maturation
2. DNA synthesis
3. Transcription
4. Translation
1; 2; 3; 4
3; 4; 1; 2
4; 1; 2; 3
2; 3; 4; 1
4; 3; 2; 1 | 2; 3; 4; 1 |
| A viral species is a group of viruses that
has the same genetic information and ecological niche.
infects the same cells and cause the same disease.
has the same morphology and nucleic acid.
cannot be defined. | has the same genetic information and ecological niche. |
| Viruses that utilize reverse transcriptase belong to the virus families
Retroviridae and Picornaviridae.
Hepadnaviridae and Retroviridae.
Rhabdoviridae and Herpesviridae.
Herpesviridae and Retroviridae.
Herpesviridae and Poxviridae. | Hepadnaviridae and Retroviridae. |
| DNA made from an RNA template will be incorporated into the virus capsid of
influenzavirus.
Retroviridae.
Hepadnaviridae.
Herpesviridae.
bacteriophage families. | Hepadnaviridae. |
| Which of the following statements about viruses is FALSE?
Viruses use their own catabolic enzymes.
Viruses use the anabolic machinery of the cell.
Viruses contain a protein coat.
Viruses have genes. | Viruses use their own catabolic enzymes. |
| A lytic virus has infected a patient. Which of the following would best describe what is happening inside the patient?
The virus is causing the death of the infected cells in the patient.
The virus is not killing any cells in the host. | The virus is causing the death of the infected cells in the patient. |
| Some viruses, such as human herpesvirus 1, infect a cell without causing symptoms. These are called
lytic viruses.
slow viruses.
latent viruses.
unconventional viruses.
phages. | latent viruses. |
| Assume a patient had chickenpox (human herpesvirus 3) as a child. Which line on the graph in Figure 13.2 would show the number of viruses present in this person as a 60-year-old with shingles (human herpesvirus 3)?
a
b
c
d
e | e |
| Assume a patient has influenza. During which time on the graph in Figure 13.2 would the patient show the symptoms of the illness?
a
b
c
d
e | c |
| The following steps occur during multiplication of herpesviruses. Which is the third step?
biosynthesis
uncoating
release
attachment
penetration | uncoating |
| The following steps occur during multiplication of retroviruses. Which is the fourth step?
uncoating
synthesis of double-stranded DNA
attachment
penetration
synthesis of +RNA | synthesis of double-stranded DNA |
| Oncogenic viruses
have no effect on the host cell.
cause acute infections.
are genetically unstable.
are lytic viruses that kill the host cell.
cause tumors to develop. | cause tumors to develop. |
| Which one of the following steps does NOT occur during multiplication of a picornavirus?
synthesis of + strands of RNA
synthesis of - strands of RNA
synthesis of DNA
synthesis of viral proteins
None of the answers is correct. | synthesis of DNA |
| Which of the following is most likely a product of an early gene?
envelope proteins
spike proteins
DNA polymerase
lysozyme
capsid proteins | DNA polymerase |
| Most RNA viruses carry which of the following enzymes?
DNA-dependent DNA polymerase
ATP synthase
lysozyme
reverse transcriptase
RNA-dependent RNA polymerase | RNA-dependent RNA polymerase |
| What is NOT true regarding viruses that infect plants?
They can sometimes be cultured in insect cells.
They can spread via pollination.
They are often cultured in embryonated chicken eggs. | They are often cultured in embryonated chicken eggs. |
| What contributes to antigenic shift in influenza viruses?
ease of virus transmission
different virus subtypes
attachment spikes
a segmented genome
worldwide distribution of the virus | a segmented genome |
| ________ were first identified in cancer-causing viruses and can induce ________ in infected cells.
Segmented genomes; reassortment
Oncogenes; transformation
Herpes viruses; lesions
T antigens; lysis | Oncogenes; transformation |
| What is an oncogene?
an altered form of a gene that may induce cancer
a viral ligand found in a family of viruses
a viral polymerase
a problematic gene found exclusively in viruses
a toxin gene transferred by a virus | an altered form of a gene that may induce cancer |
| What is the key characteristic of a transformed cell?
is producing toxins affecting neighboring cells
is infected with a lytic virus
has acquired tumor-forming properties
is producing budding viruses | has acquired tumor-forming properties |
| Shingles is an example of
reactivation of latent virus.
lytic virus.
transformation.
persistent virus.
lysogeny. | reactivation of latent virus. |
| Why do most scientists agree that viruses are nonliving entities?
They are not composed of cells.
They cause diseases in host cells.
They cannot replicate outside host cells.
They pass through filters | They are not composed of cells. |
| What type of immunity results from vaccination?
innate immunity
naturally acquired active immunity
naturally acquired passive immunity
artificially acquired active immunity
artificially acquired passive immunity | artificially acquired active immunity |
| What type of immunity results from transfer of antibodies from one individual to a susceptible individual by means of injection?
naturally acquired passive immunity
artificially acquired active immunity
artificially acquired passive immunity | artificially acquired passive immunity |
| What type of immunity results from recovery from mumps?
innate immunity
naturally acquired active immunity
naturally acquired passive immunity
artificially acquired active immunity
artificially acquired passive immunity | naturally acquired active immunity |
| Which of the following is the best definition of epitope?
specific regions on antigens that interact with haptens
specific regions on antigens that interact with antibodies
specific regions on antigens that interact with T-cell receptors | specific regions on antigens that interact with antibodies |
| Newborns' immunity due to the transfer of antibodies across the placenta is an example of
artificially acquired active immunity.
innate immunity.
naturally acquired active immunity.
naturally acquired passive immunity. | naturally acquired passive immunity. |
| Which of the following statements is NOT a possible outcome of antigen-antibody reaction?
agglutination
ADCC
activation of complement
clonal deletion
opsonization | clonal deletion |
| Which of the following cells is NOT an APC?
natural killer cells
dentritic cells
mature B cells
macrophages
None of the answers is correct; all of these are APCs. | natural killer cells |
| When an antibody binds to a toxin, the resulting action is referred to as
apoptosis.
opsonization.
ADCC.
agglutination.
neutralization. | neutralization. |
| CD4+ T cells are activated by
cytokines released by B cells.
interaction between TCRs and MHC II.
interaction between CD4+ and MHC II.
complement.
cytokines released by dendritic cells. | interaction between CD4+ and MHC II. |
| Which of the following recognizes antigens displayed on host cells with MHC II?
natural killer cell
TC cell
B cell
TH cell
basophil | TH cell |
| The specificity of an antibody is due to
the L chains.
the H chains.
the variable portions of the H and L chains.
its valence.
the constant portions of the H and L chains. | the variable portions of the H and L chains. |
| Which of the following is NOT a characteristic of B cells?
They originate in bone marrow.
They are responsible for antibody formation.
They have antibodies on their surfaces.
They recognize antigens associated with MHC I. | They recognize antigens associated with MHC I. |
| Which of the following is NOT a characteristic of cellular immunity?
The cells originate in bone marrow.
B cells make antibodies.
Cells mature in the thymus gland.
Response to abnormal cells. | B cells make antibodies. |
| Plasma cells are activated by a(n)
B cell.
T cell.
antigen.
APC.
memory cell. | antigen. |
| The antibodies found in mucus, saliva, and tears are
IgD.
IgM.
IgG.
IgA.
IgE. | IgA. |
| The antibodies found almost entirely and only on the surface of B cells (not secreted from them), and which always exist as monomers, are
IgA.
IgE.
IgG.
IgD.
IgM. | IgD. |
| The antibodies that typically bind to large parasites are
IgA.
IgE.
IgD.
IgG.
IgM. | IgE. |
| In addition to IgG, the antibodies that can fix complement are
IgM.
IgD.
IgA.
IgE. | IgM. |
| Large antibodies that agglutinate antigens are
IgG.
IgE.
IgM.
IgA.
IgD. | IgM. |
| The most abundant class of antibodies in serum is
IgM.
IgD.
IgG.
IgE.
IgA. | IgG. |
| In Figure 17.1, which letter on the graph indicates the patient's secondary response to a repeated exposure with the identical antigen?
a
b
c
d
e | c |
| In Figure 17.1, which letter on the graph indicates the highest antibody titer during the patient's response to a second and distinct/different antigen?
a
b
c
d
e | e |
| In Figure 17.1, the arrow at time (d) indicates
exposure to a new antigen.
the secondary response.
the time of exposure to the same antigen as at time (a).
the T-cell response.
the primary response. | exposure to a new antigen. |
| Which of the following statements is FALSE?
The variable region of a heavy chain is partially responsible for binding with antigen.
The constant region of a heavy chain is the same for all antibodies.
All of the answers are correct. | The constant region of a heavy chain is the same for all antibodies. |
| Which of the following is the best definition of antigen?
a pathogen
something foreign in the body
a chemical that combines with antibodies
a chemical that elicits an antibody response and can combine with these antibodies | a chemical that elicits an antibody response and can combine with these antibodies |
| Which of the following are NOT lymphocytes?
helper T cells
B cells
cytotoxic T cells
M cells
NK cells | M cells |
| The following events elicit an antibody response. What is the third step?
B cell is activated.
TH cell produces cytokines.
TH cell recognizes antigen-digest and MHC II.
Antigen-digest goes to surface of APC.
APC phagocytizes antigen. | TH cell recognizes antigen-digest and MHC II. |
| In Figure 17.2, which areas are similar for all IgG antibodies?
b and d
a and b
a and c
c and d
b and c | c and d |
| In Figure 17.2, which areas are different for all IgM antibodies?
a and b
b and c
a and c
c and d | a and b |
| In Figure 17.2, which areas represent antigen-binding sites?
a and c
b and d
b and c
a and b
c and d | a and b |
| In Figure 17.2, what portion will typically attach to a host cell?
a and c
e
b
b and c
a and d | e |
| Which of the following bacterial components would most likely result in B cell stimulation by T-independent antigens?
capsule
plasmid
flagellum
ribosome
pili | capsule |
| The presence of which of the following indicates a current infection rather than a previous infection or vaccination?
IgA
IgE
IgM
IgD
IgG | IgM |
| Which of the following destroys virus-infected cells?
B cells
dendritic cells
CTL
TH
Treg | CTL |
| The following events occur in cellular immunity, leading to a response from TH cells. What is the third step?
Antibodies are produced.
Antigen enters M cell.
TH cells proliferate.
TH cell produces cytokines. | TH cells proliferate. |
| Cytokines released by TH1 cells
convert TH1 cells to TH2 cells.
convert TH2 cells to TH1 cells.
directly kill parasites.
convert B cells to T cells.
activate CD8+ cells to CTLs. | activate CD8+ cells to CTLs. |
| Which one of the following causes transmembrane channels in target cells?
perforin
hapten
granzymes
IL-2
IL-1 | perforin |
| At a minimum, the human immune system is capable of recognizing approximately how many different antigens?
105
1025
1020
1015
1010 | 1015 |
| Thymic selection
activates B cells.
destroys B cells that make antibodies against self.
destroys T cells that do not recognize self-molecules of MHC.
destroys CD4+ cells that attack self.
destroys MHC molecules. | destroys T cells that do not recognize self-molecules of MHC. |
| Which of the following statements about natural killer cells is FALSE?
They destroy tumor cells.
They destroy cells lacking MHC I.
They destroy virus-infected cells.
They are stimulated by an antigen. | They are stimulated by an antigen. |
| An antibody's Fc region can be bound by
macrophages.
B cells.
antibodies.
CTLs.
T helper cells. | macrophages. |
| A Treg cell deficiency could result in
transplant rejection.
increased number of viral infections.
increased number of bacterial infections.
increased severity of bacterial infections.
autoimmunity. | autoimmunity. |
| ADCC is a process that is most effective in destroying
eukaryotic pathogens.
extracellular viruses.
prions.
bacterial pathogens.
bacterial toxins. | eukaryotic pathogens. |
| IL-2, produced by TH cells,
activates TC cells to CTLs.
causes phagocytosis.
stimulates TH cell maturation.
activates macrophages.
activates antigen-presenting cells. | stimulates TH cell maturation. |
| NK cells do all of the following EXCEPT
kill cells not expressing MHCI.
bind to Fc regions of bound antibodies.
become activated by TH-2 cells.
participate in antibody dependent cell cytotoxicity. | become activated by TH-2 cells. |
| Which terms regarding components of adaptive immunity are mismatched?
TH-17 cells - recruit neutrophils.
Dendritic cells- Langerhans cell.
TH cells - MHCI interaction.
M cell - microfolds.
activated macrophage - membrane ruffling. | TH cells - MHCI interaction. |
| Which of the following statements about cytokines is FALSE?
Some have multiple functions.
They are soluble proteins or glycoproteins.
They are produced by immune cells in response to a stimulus.
There are 10 types. | There are 10 types. |
| A cell undergoing apoptosis
will likely damage nearby cells.
bursts and releases intracellular contents.
was necessarily bound by antibodies.
is employed as an infection-fighting mechanism.
is a malfunction of the immune system. | is employed as an infection-fighting mechanism. |
| The importance of M cells concerns
presentation of epitopes in MHCII molecules.
ability to migrate along the intestinal tract.
facilitation of contact between antigens in the intestinal tract and the immune system. | facilitation of contact between antigens in the intestinal tract and the immune system. |
| Which of the following terms regarding roles of chemical messengers is mismatched?
hematopoetic cytokine - development of blood cells
interferons - interruption of viral infection
tumor necrosis factor - stimulate tumor metastasis | tumor necrosis factor - stimulate tumor metastasis |