MICRO 301 Exam 2 (HW)
IgM is particularly effective in cross-linking antigens because it has high affinity binding. it is a pentamer. it can class switch to IgG. it is produced by plasma cells. it is a dimer.
it is a pentamer.
The microbe is digested within the phagocyte by enzymes delivered by a _______. mitochondrion bacterium lysozyme phagosome lysosome
lysosome
Bacteriophages involved in generalized transduction are ______ phages. lysogenic temperate lytic rupturing filamentous
lytic
What are the two entry mechanisms used by enveloped viruses? Fusion and uncoating Fusion and budding Fusion and endocytosis Endocytosis and uncoating Fusion and exocytosis
Fusion and endocytosis
What is the role of Taq polymerase? It anneals the primers to the template DNA strand. It catalyzes the synthesis of the new DNA chains. It forms hydrogen bonds between complementary bases. It indicates the starting point for building the new DNA chains. It breaks apart the DNA strands for the building process.
It catalyzes the synthesis of the new DNA chains.
Which of the following statements about Thiomargarita namibiensis are TRUE? It stores nitrate, its terminal electron acceptor. It stores sulfur, its energy source. It produces a sheath that allows it to move between sediment and the water above. Its name means "sulfur pearl of Namibia." It is a motile bacterium, possessing a tuft of terminal flagella. It
It stores nitrate, its terminal electron acceptor. It stores sulfur, its energy source. Its name means "sulfur pearl of Namibia."
What term describes the type of bacteriophage infection cycle where the bacteriophage DNA is inserted into the host cell DNA as a prophage and the infected bacteria can continue to grow and divide? Oncogenic Hemorrhagic Lytic Lysogenic Transforming
Lysogenic
A ______ contains hydrolytic enzymes to digest foreign bacteria. ribosome lysosome complesome lysozyme phagosome
Lysosome
Which molecule is responsible for displaying fragments of proteins made within the cell and would therefore be useful in detecting a virally infected cell? Adhesins CD4 Ligands MHC Peptidoglycan
MHC
Antigenic fragments are complexed with ______ and displayed on the surface of the infected cell. cytokines receptors MHC class II molecules MHC class I molecules All of the answer choices are correct.
MHC class I molecules
______ are the precursors to macrophages. Eosinophils Basophils Lymph nodes Mast cells Monocytes
Monocytes
After helper T-cell activation, which of the following are produced? Cytokines TH and TC cells TH effector cells and TH memory cells TH cells and B cells TH plasma cells and TH memory cells
TH effector cells and TH memory cells Cytokines
Helper T cells ______. make MHC class II molecules circulate in low numbers in the blood stimulate B cells and other T cells mature in the bone marrow produce antibodies
stimulate B cells and other T cells
The polymerase used in the polymerase chain reaction comes from a thermophilic bacterium. A thermophile grows best between 45° and 80°C 0° and 70°C 20° and 40°C -10° and 10°C 5° and 70°C
45° and 80°C
Antigen-presenting cells may be B cells. may be macrophages. present antigen fragments on their surface. All of the answer choices are correct. may be dendritic cells.
All of the answer choices are correct.
Surface receptors on immune system cells function in ______. cell development communication identification of self/non-self molecules All of the answer choices are correct. None of the answer choices is correct.
All of the answer choices are correct.
The advantageous genes that can be transferred by transduction are genes for sugar fermentation. toxin production. drug resistance. All of the answer choices are correct. None of the answer choices is correct.
All of the answer choices are correct.
Tissue injury leading to inflammation can be due to chemical injury. infection. mechanical injury. All of the answer choices are correct. None of the answer choices is correct.
All of the answer choices are correct.
To carry out Sanger (dideoxy chain termination) sequencing a mixture is needed containing single-stranded DNA. DNA polymerase. four deoxyribonucleotides A, T, C, G. RNA polymerase. All of the answer choices are correct.
All of the answer choices are correct.
Which of the following cells can be a target for cytotoxic T cells? Transplanted cells. Virus-infected cell. Cancer cells. Only cancer cells and virus-infected cells. All of the answer choices are correct.
All of the answer choices are correct.
For which of the following can PCR be used? Recombinant DNA technology. Paternity testing. All of the given choices. Identification of individuals. Crime scene investigation.
All of the given choices.
Which of the following antimicrobial substances are not part of our body's first line defenses? Lysozyme Mucus Antibodies Hydrochloric acid Lactic acid
Antibodies
______ are molecules that stimulate a response in T cells and B cells. Platelets Monocytes Antigens Leukocytes Antibodies
Antigens
Extreme halophiles/extreme thermophiles are members of the domain ______.
Archaea
________ are prokaryotic organisms recently classified as belonging to their own domain.
Archaea
Which of the following is part of the body's adaptive defense? Phagocytes B cells Inflammation Complement Interferons
B cells
Which role does histamine play during inflammation? It leads to vasodilation. It promotes margination of neutrophils. It causes sneezing. It raises blood pressure. It destroys bacteria.
It leads to vasodilation.
Characteristics that define archaea, however, include the presence of unique membrane ________, ________ construction and composition, and _____________ pathways.
Lipids, Cell wall Metabolic
______ with antigen fragments displayed on their surfaces are known as antigen-presenting cells (APCs). Basophils Macrophages T cells RBCs Neutrophils
Macrophages
When present, of what is the viral envelope composed? Carbohydrates Proteins and sugars Mainly protein Mainly lipids Nucleic acid
Mainly lipids
Which of the following is a mechanism used by pathogens for avoiding antibodies? Molecular mimicry Producing C5a peptidase Producing cytotoxins Stimulating cytotoxic T cells Killing cytotoxic T cells
Molecular mimicry
The process of antibody-dependent cellular cytotoxicity (ADCC) allows ____________ cells to bind to antibody-coated host cells that may have viral proteins in their plasma membrane in order to kill them, inducing apoptosis and limiting viral spread.
Natural Killer
Which cell type is capable of phagocytosis? Neutrophils and macrophages. Only macrophages. Mast cells and basophils. B cells and T cells. Only neutrophils.
Neutrophils and macrophages.
Which of the following bacteria can oxidize large amounts of ammonia-containing waste, consuming so much oxygen in the process that they can create hypoxic areas of water? Hydrogen-oxidizing bacteria Sulfur-oxidizing bacteria Cyanobacteria Nitrifying bacteria Facultative anaerobes
Nitrifying bacteria
Microbes growing in nodules on the roots of plants can form an agriculturally important symbiotic ______-fixing relationship. Microbes in this group are collectively referred to as rhizobia.
Nitrogen
Activated complement proteins play a part in eliminating microbial invaders from a host. They belong to the group of non-specific immune responses. Which of these is NOT part of that group? Phagocytosis Fever Plasma cells Inflammation Interferons
Plasma cells
Much work is currently being done toward global eradication of which of the following diseases? Influenza Ebola virus disease The common cold Polio All of the answer choices are correct.
Polio
What is the major difference between polyclonal antibodies and monoclonal antibodies? Monoclonal antibodies bind to different epitopes while polyclonal will bind to only one type of epitope. Polyclonal antibodies are harder to make than monoclonal antibodies. Polyclonal antibodies bind to different epitopes while monoclonal will bind to only one type of epitope. Polyclonal antibodies are generated from T cells while monoclonal are from B cells. Polyclonal antibodies typically contain many different antibody classes.
Polyclonal antibodies bind to different epitopes while monoclonal will bind to only one type of epitope.
Please choose the correct statement that describes the actions of methanogens in the carbon cycle. Produce methane in aerobic ecosystems Produce nitrogen in anoxygenic ecosystems Produce carbon dioxide in aerobic ecosystems Produce carbon dioxide in anaerobic ecosystems Produce methane in anaerobic ecosystems
Produce methane in anaerobic ecosystems
In addition to perforins, what else is secreted by cytotoxic T cells? Lysozyme Histamine Proteases (e.g. granzymes) Interferon Antibodies
Proteases (e.g. granzymes)
During viral infection of a host cell, which is the third step of the process? Uncoating and nucleic acid release Entry (fusion or endocytosis) into host cell Attachment to host cell Biosynthesis of virion components Release of nucleocapsid into host cytoplasm
Release of nucleocapsid into host cytoplasm
The natural habitat of a pathogen or microorganism is called its ______ and can either be living (humans, animals) or non-living (soil, water, air).
Reservoir
Please choose the statement that best describes the role of restriction enzymes in genetic engineering. Restriction enzymes are used to cut DNA at specific locations. Restriction enzymes are used to sequence long stretches of DNA. Restriction enzymes are used to purify DNA. Restriction enzymes are used to join different segments of DNA. Restriction enzymes are used to replicate specific sequences of DNA.
Restriction enzymes are used to cut DNA at specific locations.
The ________ and protein sequences of archaea are more closely related to those of eukaryotes than those of bacteria.
Ribosomal
Please select the pair that is incorrectly matched. Siderophores - injecting toxins IgA protease - disrupting mucosal surface protection Adhesins - pili, capsules, or cell wall components Fimbriae - attachment to host Injectisome - delivering effector proteins into host cell
Siderophores - injecting toxins
Why is the DNA cooled slightly after it is denatured? To allow the primers to anneal to their complementary sequence on the target DNA. To allow the primers to detach from their complementary sequence on the target DNA. To protect the polymerase enzyme from denaturation. To allow the hydrogen bonds to reform between the template DNA strands. To save energy in the thermal cycler.
To allow the primers to anneal to their complementary sequence on the target DNA.
What is the general purpose of the PCR process? To analyze the sequence of phosphates in an RNA fragment. To make many copies of a small target piece of DNA. To analyze the sequence of bases in a DNA fragment. To make many copies of a small target piece of RNA. To analyze the sequence of bases in an RNA fragment.
To make many copies of a small target piece of DNA.
Apoptosis occurs in infected host cells, as well as during positive and negative selection in lymphocyte development. T/F
Treu
A helper T cell must be activated before it can stimulate a B cell to produce antibody. T/F
True
A helper T cell must be activated before it can stimulate a B cell to produce antibody. T/F
True
A person deficient in cytotoxic T cells may be more susceptible to developing cancer. T/F
True
Almost immediately upon entry, the viral nucleic acid alters the gene expression of the host cell. T/F
True
An example of microbial evolution is the development of antimicrobial drug resistance in microbes as a result of overuse/misuse of medications by humans. T/F
True
Antibodies can bind to antigens to form immune complexes that can settle in the kidneys, resulting in kidney damage. T/F
True
Antigen fragments are presented at the surface of macrophages along with self proteins. T/F
True
Antigen fragments are presented at the surface of macrophages along with self proteins. T/F
True
Both antigen-presenting cells and B cells have class II MHC receptors on their surface. T/F
True
Both enveloped and non-enveloped (naked) viruses can enter a cell by endocytosis. T/F
True
Complement factor C3b coats a bacterium and binds to C3b receptors on phagocytes, making the bacterium more susceptible to being phagocytized. T/F
True
Cytotoxic T cells produce cytotoxins and perforins which cause death of the infected cells. T/F
True
Examining the electrophoresis gel and reading from bottom to top, one base at a time, gives the sequence of DNA. T/F
True
If a bacterium could escape from a phagosome, it would be able to resist digestion by that phagocyte. T/F
True
In order for viruses to enter host cells, they must bind to receptors on the host cytoplasmic membrane. T/F
True
It is possible for one host to be resistant to infection by a pathogen that can normally cause disease in a different host. T/F
True
A fomite is an animal that transmits a disease through a bite. anything that is involved in pathogen transmission. a child that doesn't practice good hygiene. a non-living object that can be the source of infection. an insect that transmits disease.
a non-living object that can be the source of infection.
The F pilus is a polymer of peptidoglycan that binds to the recipient's cell wall. a protein appendage that attaches the two cells together. a modified microfilament that is used for movement. a protein appendage that attaches Gram-negative cells to surfaces. a projection of the cell's cytoplasmic membrane.
a protein appendage that attaches the two cells together.
Phagocytosis can be enhanced by immunological mediators such as ______. antigens activated complemented proteins enzymes complement receptors vasodilators
activated complemented proteins
The polymerase chain reaction uses DNA polymerase but not primase or helicase. Primase is usually responsible for unzipping the parental DNA strands. adding a short sequence of complementary RNA to the existing single DNA strand. cutting parts of the parent DNA strands so that the polymerase can attach. creating peptide bonds between nucleotides. joining Okazaki fragments together.
adding a short sequence of complementary RNA to the existing single DNA strand.
The plasmid is mobilized for transfer when an endonuclease cleaves it at the origin of transfer. it is glycosylated by the Golgi complex. a helicase unwinds the two strands. DNA polymerase cleaves it at the origin of transfer. single-strand stabilizing proteins attach to it.
an endonuclease cleaves it at the origin of transfer.
The basic parts of a bacteriophage are an isohedral head, tail, tail pins, and fibers. a helical capsid, envelope, and spikes. an icosahedral capsid, envelope, and tail. a helical capsid, envelope, tail pins, and spikes. a tail, envelope, tail pins, and fibers.
an isohedral head, tail, tail pins, and fibers.
The levels of IgG in an infant go down after birth because the maternal antibodies gradually degrade. B cells gradually die. memory cells gradually die. T cells become activated. All choices are true.
antibodies gradually degrade.
A child with a genetic disorder that does not allow immature B cells to develop would therefore not be able to make cytokines. interleukin-1. memory cells. antibodies. interleukin-2.
antibodies.
After entry of the bacteriophage into the host cell, a phage enzyme breaks down the host cell cytoplasmic membrane. activates host cell ribosomes. breaks down the host cell nuclear membrane. breaks the viral capsid into fragments. breaks the host DNA into fragments.
breaks the host DNA into fragments.
When the bacteriophage transfers bacterial DNA into a recipient bacterial cell, this DNA triggers the formation of an endospore. can integrate into the chromosome. hybridizes with RNA present in the cell. circularizes and forms a plasmid. lyses the bacterial host immediately.
can integrate into the chromosome.
DNA polymerase: can only add nucleotides to single-stranded DNA with a primer sequence. can add nucleotides to double-stranded DNA. can add nucleotides in two different directions. can only add nucleotides to single-stranded RNA with a primer sequence. fills in gaps in DNA.
can only add nucleotides to single-stranded DNA with a primer sequence.
T-dependent antigens include molecules with identical repeating subunits. are very uncommon. can activate B cells without helper T cell assistance. characteristically have a protein component. seldom have a protein component
characteristically have a protein component.
The four classic signs and symptoms of inflammation include all the following EXCEPT swelling. pain. heat. chills. redness.
chills.
In phagocytosis, the digested contents are eliminated by ______. opsonization exocytosis pinocytosis endocytosis phagocytosis
exocytosis
Cytotoxic T cells kill target cells by exposing them to chemicals that induce apoptosis. recruiting phagocytes to engulf the target cell. ingesting the target cell and exposing it to peroxidases. exposing them to alpha-interferon. activating C5 and forming membrane attack complexes.
exposing them to chemicals that induce apoptosis.
The experiment involved the transfer and expression of ______ DNA into bacterial cells. viral cow human frog mouse
frog
Helper T cells function sometimes in cell-mediated and other times in humoral immunity. function only in humoral immunity by secreting antibodies. function in both cell-mediated and humoral immunity. function only in cell-mediated immunity. function in both cell-mediated and innate immunity.
function in both cell-mediated and humoral immunity.
Hfr refers to a cell that has integrated the F plasmid into its cytoplasm. refused to integrate the F plasmid into the cell. integrated the F plasmid into its genome. integrated the F plasmid into its cell wall. integrated the F plasmid into its sex pilus.
integrated the F plasmid into its genome.
The adaptive immune response involves cell-mediated immunity only. is part of the first line of defense. involves humoral immunity only. involves B lymphocytes only. involves memory of antigens from previous exposure.
involves memory of antigens from previous exposure.
Removal of the capsid to release the virus nucleic acid into the host cytoplasm is called ______. uncoating decoating desynthesis endocytosis fusion
uncoating
Margination occurs when neutrophils stick to the lining of the endothelium.
True
More than one mechanism of viral entry into a host cell exists. T/F
True
Nitrogen fixation and ammonification are two different reactions in the nitrogen cycle that yield ammonium as a product. T/F
True
Phagocytosis is part of the body's innate immune defenses. T/F
True
The donor cell DNA is integrated into the recipient cell's DNA by homologous recombination. T/F
True
M cells in the intestinal epithelium are important because pathogenic bacteria such as Shigella species
Use them to gain access to underlying issues
Which type of test would be most accurate for determining if an individual had antibodies against a specific protein subunit of cholera toxin? Direct FA tests Direct ELISA Western blot Indirect ELISA Indirect FA tests
Western blot
What is the antibody titer in a sample when there is a detectable antigen-antibody reaction in the 1:20 dilution, 1:40 dilution, but not in the 1:80 dilution? 1/40 40 80 20 10
40
How many copies of the DNA segment of interest would there be after 3 cycles of the polymerase chain reaction? 4 3 2 8 6
8
Which of the following is NOT a function of inflammation? Contain microbes at the site of damage. Activate the complement system. These are all functions of the complement system. Restore tissue function to normal. Eliminate foreign microbes and matter.
Activate the complement system.
In animal virus replication, an uncoating step is needed to release the nucleic acid from the capsid. Why is this step not needed in bacteriophage replication? Bacteriophages only contain protein and lipids. Bacteriophages do not replicate. Bacteriophages inject their DNA into the host cell. Uncoating is also needed in the phage life cycle. Bacteriophages only contain RNA.
Bacteriophages inject their DNA into the host cell.
How are microbes killed and digested in the phagolysosome? By lipases. By alkaline digestion. By acid digestion. By phagocytes. By hydrolytic enzymes.
By hydrolytic enzymes.
Both the classical and alternative complement pathways create C4a and C4b. C1. C3 convertase. C3 coperdin. properdin.
C3 convertase.
Which of the following Escherichia coli cells did NOT produce colonies on the growth medium containing tetracycline? Cells that picked up a plasmid without any foreign genes. Cells that did not pick up a plasmid. All of these types of cells produced colonies Cells that picked up a recombinant plasmid containing another gene. Cells that picked up a recombinant plasmid containing the ribosomal DNA gene.
Cells that did not pick up a plasmid.
All viruses can infect any cell type or tissue type. T/F
False
Adaptations to their metabolic pathways allow archaea to live in extreme environments, such as areas with high levels of salt (___________) or high temperatures (_____________).
Halophiles thermophiles
Why is the DNA heated to over 90 degrees Celsius to start the process? Heat allows the primers to anneal to the starting area on the target DNA. Heat allows the building of the chains to occur at a double rate. High heat keeps the polymerase enzyme active. High heat denatures proteins that interfere with the PCR process. Heat denatures the DNA, meaning it separates the two strands.
Heat denatures the DNA, meaning it separates the two strands.
Dimer that is a significant component of mucus and secretions IgM IgE IgD IgG IgA
IgA
Involved in the development/maturation of immune response IgM IgE IgD IgG IgA
IgD
Which of the following about hydrothermal vents is FALSE? Photosynthesis supports food production in the region. Prokaryotes thriving in the region can withstand autoclave temperatures. All of the statements are true. Prokaryotes that thrive there are hyperthermophiles. Many of the microbes in the vents live symbiotically with eukaryotes in the region.
Photosynthesis supports food production in the region.
Which of the following are limitations of Koch's postulates? The suspected pathogen infects animals but not humans. The suspected pathogen cannot be cultured in the laboratory. There is not a suitable experimental host for the suspected pathogen. The suspected pathogen produces disease both in humans and a suitable test animal. The disease is polymicrobial, caused by more than one pathogen.
The suspected pathogen cannot be cultured in the laboratory. There is not a suitable experimental host for the suspected pathogen. The disease is polymicrobial, caused by more than one pathogen.
What is the function of selectins? They raise body temperature during inflammation. They promote sticking of neutrophils to the inner vessel wall. They release histamine causing redness and swelling. They are found in phagocytes and digest bacteria. They reduce swelling and redness at the site of an injury.
They promote sticking of neutrophils to the inner vessel wall.
Generalized transduction occurs when specific bacterial genes are replicated by a bacteriophage. DNA passes from one bacterial cell to another by a sex pilus. a bacterial cell packages a piece of viral DNA during replication. a bacteriophage packages a piece of bacterial DNA during replication. specific bacterial genes are deleted by a bacteriophage.
a bacteriophage packages a piece of bacterial DNA during replication.
Hfr refers to a cell in which the F plasmid and R plasmid have been integrated into the cell chromosome. a cell with an F plasmid in the cytoplasm. a cell that has lost its F plasmid. a cell in which the F plasmid has been integrated into the cell chromosome. a cell that has combined with other cells by sexual reproduction.
a cell in which the F plasmid has been integrated into the cell chromosome.
An antigen-presenting cell presents antigen to a helper T cell on its surface using ______. a class II MHC molecule a T cell receptor a CD receptor a B cell receptor a class I MHC molecule
a class II MHC molecule
An antigen-presenting cell presents antigen to a helper T cell on its surface using ______. a class II MHC molecule a T cell receptor a CD receptor a B cell receptor a class I MHC molecule
a class II MHC molecule
During maturation or formation of phage particles single strands of bacterial and viral DNA hybridize. chromosomal fragments start to reassemble. viral DNA is wrapped in an endocytic vesicle and released. the host nuclear membrane reforms. a few phage heads may surround fragments of host bacterial DNA.
a few phage heads may surround fragments of host bacterial DNA.
T-cell receptors (TCRs) are only capable of recognizing and responding to antibody-coated antigens. antigen epitopes presented on major histocompatibility (MHC) molecules. free antigen molecules. major histocompatibility (MHC) molecules on self cells. virus antigens presented on self-cells.
antigen epitopes presented on major histocompatibility (MHC) molecules.
A helper T cell becomes activated by a(n) ______. phagocyte helper B cell enzyme antigen-presenting cell cytotoxic T cell
antigen-presenting cell
Antigens are universal molecules shared by many microbes. refers to any molecule found inside the body. are only found inside or on the surface of microbes. are molecules that can be recognized by B or T cells. All answer choices are correct.
are molecules that can be recognized by B or T cells.
T cells make antibodies. are responsible for humoral immunity. all carry out the same functions. are responsible for cell-mediated immunity. arise and mature in the bone marrow.
are responsible for cell-mediated immunity.
Viral spikes are made of lipids. attach specifically to host cell receptors. are present in all viruses. attach non-specifically to host cell receptors. are composed of polysaccharides.
attach specifically to host cell receptors.
Viruses that infect bacterial cells are called ______. bacteriophages viroids toxins bacteriocins bacteriviri
bacteriophages
A positive (+) strand of RNA must be converted back to DNA for gene expression. can directly act as mRNA. cannot function directly as mRNA. makes a minus (-) strand of RNA, which can then act as mRNA. must be double-stranded.
can directly act as mRNA.
The chickenpox vaccine is not recommended for someone who has AIDS or a similar immunodeficiency. Based on this information, you conclude that the vaccine likely contains an attenuated strain. is a conjugate vaccine. contains subunits of a virus. contains killed bacterial cells. is a toxoid.
contains an attenuated strain.
After repeated exposure to foreign material, innate immunity begins to react less strongly. continues to react the same way. involves a wider range of cells and mediators. reacts more quickly and intensely. shuts down completely.
continues to react the same way.
The membrane attack complex kills cells by blocking protein synthesis. creating holes in cell membranes. causing apoptosis of phagocytes. generating toxic oxygen molecules. degrading the genetic material.
creating holes in cell membranes.
Every virus particle contains ______. DNA and RNA phospholipids DNA ribosomes either DNA or RNA
either DNA or RNA
Which the following is an advantage of an oral vaccine over an injected one? Oral vaccines can be inactivated. elicit a strong IgG response. elicit a strong IgA response. elicit a strong IgM response. can be attenuated.
elicit a strong IgA response.
The three primary functions of complement activation are enhancing phagocytosis, causing inflammation, and killing target cells. inactivating toxins, binding viruses, and killing target cells. triggering bone marrow production of macrophages, causing inflammation, and killing target cells. enhancing phagocytosis, causing inflammation, and triggering fever. inactivating toxins, stimulating hematopoiesis, and killing target cells.
enhancing phagocytosis, causing inflammation, and killing target cells.
Phagocytes are attracted by all of the following EXCEPT phospholipids released by injured cells. chemical products of microorganisms. enzymes released by lysosomes. components of the complement system.
enzymes released by lysosomes.
The primer used in Sanger (dideoxy chain termination) sequencing must have a sequence beginning and ending with the same nucleotide. can have any random nucleotide sequence. has a nucleotide sequence complementary to the 5' end or the 3' end of the region to be copied. has a nucleotide sequence complementary to the 5' end of the region to be copied. has a nucleotide sequence complementary to the 3' end of the region to be copied.
has a nucleotide sequence complementary to the 3' end of the region to be copied.
F+ cells lack a chromosome and are recipients in conjugation. lack a plasmid and are recipients in conjugation. have a plasmid and are recipients in conjugation. have a plasmid and are donors in conjugation. lack a plasmid and are donors in conjugation.
have a plasmid and are donors in conjugation.
The complement system components react in a cascade. randomly. in parallel. simultaneously. in reverse.
in a cascade.
Plasmid DNA is transferred in double-stranded form. in 100 bp fragments. as an RNA copy. via aquaporins in the cell membrane. in single-stranded form.
in single-stranded form.
Primary producers can be either photoautotrophs (using sunlight for energy) or chemolithotrophs (oxidizing ______ chemicals for energy).
inorganic
The immune system responds more quickly to second exposure to an antigen because macrophages are activated during the first exposure. memory B cells are produced during the first response. less T cells are made in response to the antigen. more T cells are made in response to the antigen. more B cells are made in response to the antigen.
memory B cells are produced during the first response.
B cells differentiate into plasma cells and ______. memory cells mediator cells helper T cells cytotoxic T cells macrophages
memory cells
Bacteriophages adsorb or attach: only to members of the same bacterial species. non-specifically to bacterial cell walls. only to members of the same family. only to members of the Archaea. to plant and animal cells.
only to members of the same bacterial species.
Viral capsids are composed of ______. lipids phosphates nucleic acids carbohydrates protein
protein
The complement system comprises a group of ______ found in the bloodstream. proteins phospholipids nucleic acids steroids carbohydrates
proteins
All of the following cells have class II MHC receptors on their surface EXCEPT dendritic cells. macrophages. red blood cells. B cells. neutrophils.
red blood cells.
Cytotoxic T cells cause death of infected cells by releasing interleukin-2 that destroys the viruses in the infected cell. recruiting phagocytes that engulf and destroy helper T cells. producing interferons that inhibit viral replication inside the infected cell. releasing cytotoxins, perforins, and enzymes that destroy the cell. producing antibodies that neutralize the viruses.
releasing cytotoxins, perforins, and enzymes that destroy the cell.
Primers are used for catalyzing the synthesis of new DNA chains. breaking apart the DNA strands for the synthesis process. indicating the correct complementary sequence to the target DNA. showing the polymerase enzyme where to begin building the new DNA chain. showing the polymerase enzyme where to begin building the new RNA chain.
showing the polymerase enzyme where to begin building the new DNA chain.
During conjugation, the donor chromosome is transferred as a whole F plasmid. single-stranded DNA. single-stranded RNA. double-stranded RNA. double-stranded DNA.
single-stranded DNA.
Genes from the donor chromosome are transferred as single-stranded RNA. single-stranded DNA. double-stranded RNA. a plasmid. double-stranded DNA.
single-stranded DNA.
The F pilus binds to endocytic vesicles on the recipient plasma membrane. specific receptors on the cell wall of the recipient. techoic acid in the cell wall of the recipient. ploysaccharides on the recipient's capsule. lipopolysaccharide on the Gram-negative envelope.
specific receptors on the cell wall of the recipient.
Cytotoxic T cells know that a cell is infected because it can detect microbes within the infected cells. it can recognize self antigens on the surface of the infected cell. infected cells are a totally different shape from healthy cells. it can recognize MHC molecules on the infected cell surface. that cell has antigens from the disease-causing microbe on its surface.
that cell has antigens from the disease-causing microbe on its surface.
F+ refers to a cell containing a double strand of DNA. a functional strand of DNA. a single strand of DNA the F plasmid. any plasmid.
the F plasmid.
If a TC encountered a TH cell infected with a virus, both cells would die. nothing would happen because the TH cell only expresses MHC class II molecules. it would destroy the virus while leaving the TH cell unharmed. the TC cell would induce apoptosis in the TH cell.
the TC cell would induce apoptosis in the TH cell.
In viral entry by endocytosis the host's cells cytoplasmic membrane surrounds only the viral protein coat. viral spikes fuse with the host cell's cytoplasmic membrane to form a vesicle. the host cell's cytoplasmic membrane surrounds the whole virion and forms a vesicle. the host cell's cytoplasmic membrane surrounds only the viral nucleic acid. lipases degrade the viral coat to release the viral nucleic acid.
the host cell's cytoplasmic membrane surrounds the whole virion and forms a vesicle.
Which event occurs in the early stages of inflammation? Macrophages appear and begin phagocytosis. The blood cells in the inflamed area vasoconstrict. Chemical mediators and cytokines are released from injured cells. Mast cells and basophils appear and begin phagocytosis. Exudate and pus accumulate at the site of injury or infection.
Chemical mediators and cytokines are released from injured cells.
In areas with no sunlight, ______ obtain energy by oxidizing hydrogen sulfide and fix CO2, providing animals in the area with both a carbon and an energy source.
Chemolithotrophs
What is the name of the process by which phagocytes move towards microbial products? Chemaxis Diffusion Chemotaxis Chemomovement Photosynthesis
Chemotaxis
Which of the following is part of the body's sensor systems? Vomiting Helper T cells Cytotoxic T cells Complement proteins Saliva
Complement proteins
Please choose the term that describes a virus that has a lipid bilayer (derived from the host cell) surrounding its capsid. Non-enveloped (naked) virus Enveloped virus Coated virus Encapsulated virus Icosahedral virus
Enveloped virus
Select which of the following are mechanisms used by pathogens for surviving phagocytosis. Escaping from the lysosome. Escaping from the phagosome. Preventing formation of the phagolysosome. Surviving within a phagolysosome. Preventing opsonization. Avoiding lytic enzymes in the phagolysosome
Escaping from the phagosome. Preventing formation of the phagolysosome. Surviving within a phagolysosome.
Although they share many characteristics with bacteria, members of the Domain Archaea are more closely related to Domain ________ than to bacteria.
Eukarya
Which of the following serological methods is used to enumerate and sort specific cell types? FA test Western blot ELISA FACS Gel electrophoresis
FACS
After a B cell is activated to form plasma cells, those plasma cells each produce different antibodies. T/F
False
After conjugation of an Hfr cell and an F- cell, the entire genome of the Hfr cell is usually transferred to the recipient cell. T/F
False
Generalized transduction involves the transfer of phage genes from one bacterial cell to another. T/F
False
Generalized transduction is so called because specific bacterial genes are transferred during this process. T/F
False
Mitochondria contain hydrolytic enzymes. T/F
False
T-independent antigens will produce strong, high-affinity IgD responses from B lymphocytes. T/F
False
The Centers for Disease Control and Prevention has no input in prevention policies implemented by hospital Infection Control Committees. T/F
False
The complement system is part of the specific immune response. T/F
False
The entire genome of the donor cell is usually transferred to the recipient cell. T/F
False
There are no antigens that can stimulate B cells without T cell help. T/F
False
Which of the following are reasons that made smallpox virus a good target for eradication? Human beings were the only reservoir for the virus. There was only a single animal reservoir for the virus. The symptoms of the disease were highly evident and obvious. An effective vaccine was able to be produced and administered across the globe. Administration of the live attenuated vaccine to the U.S. population only gradually led to immunization of the rest of the world as Americans traveled abroad. Obviously infected individuals were able to be quarantined quickly to prevent spread of the infection to other susceptible individuals. Low levels of mortality induced by the disease gradually left most of the global population immune to reinfection. The virus burned itself out. Correct
Human beings were the only reservoir for the virus. The symptoms of the disease were highly evident and obvious. An effective vaccine was able to be produced and administered across the globe. Obviously infected individuals were able to be quarantined quickly to prevent spread of the infection to other susceptible individuals.
Mediates allergic responses IgM IgE IgD IgG IgA
IgE
Most prevalent antibody in circulation IgM IgE IgD IgG IgA
IgG
Which of the following is the only antibody class capable of crossing the placenta? IgD IgG IgE IgA IgM
IgG
Pentameric in circulation IgM IgE IgD IgG IgA
IgM
Antigen-presenting cells release what cytokine to activate helper T cells? Interleukin-1 Antibody Interferon Leukotrienes Interleukin-2
Interleukin-1
When activated by antigen-presenting cells, helper T cells release what cytokine that activates B cells and cytotoxic T cells? Interleukin-1 Complement Interleukin-2 Interleukin-3 Interferon
Interleukin-2
Please choose the statement that best describes the role of a cloning vector. Introduce DNA into a cloning host. Isolate DNA from a donor organism. Separate fragments of DNA. Screen for recombinants that have been successfully transformed. Detect the presence of specific DNA is a sample.
Introduce DNA into a cloning host.
A disease is included on the Notifiable Infectious Diseases List for the CDC if it is transmitted by airborne respiratory droplets. is of relatively high incidence or poses potential danger to public health. causes permanent damage or is fatal in those who contract it. is transmitted by sexual contact. is caused by an infectious agent.
is of relatively high incidence or poses potential danger to public health.
The negative (-) sense strand of RNA acts as mRNA to make viral proteins. plays no role. is used to synthesize more (+) strands. is identical to the (+) sense strand. makes RNA replicase.
is used to synthesize more (+) strands.
In transduction, bacterial DNA is transferred to a new cell when it binds to a receptor on the bacterial cell wall. something triggers the host to produce new DNA. the virus is brought into the host by endocytosis. it is injected by the virus. it binds to a receptor on the host cytoplasmic membrane.
it is injected by the virus.
Extravasation, also known as diapedesis or transmigration, occurs when neutrophils move away from the infecting bacteria. neutrophils squeeze through the blood vessel wall. blood vessels dilate and become leaky. neutrophils are attracted to the infecting bacteria. neutrophils stick to the blood vessel wall.
neutrophils squeeze through the blood vessel wall.
After host cell DNA is broken down by a viral enzyme phage DNA is replicated and phage coat proteins are produced. the host cytoplasmic membrane is degraded by viral enzymes. viral proteins begin their assembly and maturation. the host fragments are reassembled into viral DNA. viral spike proteins are inserted into the bacterial cytoplasmic membrane.
phage DNA is replicated and phage coat proteins are produced.
After being engulfed, a microbe is found within a _______. lysosome phagosome pinocyte pinosome phagolysosome
phagosome
B cells differentiate into ______, which make antibodies. macrophages plasma cells phagocytes helper cells T cells
plasma cells
The antibody-producing progeny of an activated B cell are called ______. bursa cells memory cells plasma cells phagocytes antibodies
plasma cells
A difference between plasmids and fragments of DNA that have been transferred between cells is: A. DNA fragments are more stable. B. only plasmids can transfer drug resistance genes. C. DNA fragments can replicate independently. D. plasmids can replicate independently. E. only DNA fragments can transfer drug resistance genes.
plasmids can replicate independently.
Taq polymerase is specifically used in this process because it is eukaryotic in origin. unstable at high temperatures. stable at high temperatures. cheap and easy to obtain. bacterial in origin.
stable at high temperatures.
After the conjugation of an Hfr cell with an F- cell, the recipient becomes F+. the recipient remains F-. the donor becomes F-. the recipient becomes Hfr. the donor becomes F- and R+.
the recipient remains F-.
A ______ is used to automatically expose the polymerase chain reaction to repetitive steps, yielding large amounts of DNA in a short period of time. Western blot sequencer thermal cycler restriction endonuclease hybridization test
thermal cycler
The polymerase chain reaction uses DNA polymerase but not primase or helicase. Helicase is usually responsible for adding a short sequence of complementary RNA to the DNA template. supercoiling the DNA. cutting parts of the parent DNA so that the polymerase can attach. forming hydrogen bonds between DNA strands. unzipping the parent DNA strands.
unzipping the parent DNA strands.
The symptoms of inflammation are mostly due to ______. phagocytosis vasodilation extravasation (diapedesis) pinocytosis margination
vasodilation
Cytotoxic T cells recognize ______. receptors on B cells viral antigens and class I MHC molecules viral antigens and class II MHC molecules fragments of self proteins on infected cells bacterial antigens and class II MHC molecules
viral antigens and class I MHC molecules