Microbiology Final Practice
Intracellular pathogens sometimes produce ________ that can kill phagocytes. PAMPs PRRs Lipopolysaccharides Leukocidins
Leukocidins
________ is the acquired inability to mount an adaptive immune response against self. Tolerance Specificity Immunogenicity Memory
Tolerance
________ is a damage or injury to a host organism that impairs its function. disease transmission trauma infection
disease
Which of the following is a major growth-limiting micronutrient that influences microbial growth? sugar water iron vitamin K
iron
Exotoxins are ________, but endotoxins are ________. ipids / proteins carbohydrates / proteins proteins / lipopolysaccharide-lipoprotein complexes lipopolysaccharide-lipoprotein complexes / proteins
proteins / lipopolysaccharide-lipoprotein complexes
The spread of pathogens through the blood and lymph systems that results in a bloodborne systemic infection is called pathogenesis septicemia cancer bacteremia
septicemia
An outer coat consisting of a dense, well-defined polymer layer surrounding a cell and used in attachment is called a Cytoplasmic membrane Capsule Lipopolysaccharide layer pilus
Capsule
Cytokine secreted by macrophages IL-12 CCL2 IL-6 CXCL 8
IL-6
Type I hypersensitivity is caused by the release of vasoactive products from mast cells coated with IgM IgG IgA IgE
IgE
Antibody-mediated immunity is particularly effective against Intracellular pathogens Extracellular pathogens Both of the above None of the above
Extracellular pathogens
A high-affinity antibody binds nonspecifically and loosely to an antigen. True False
False
All AB toxins have which of the following? Lipid A Hemolytic activity Immunogenic properties Two subunits
Two subunits
TH cells express a ________ protein coreceptor. CD8 CD4 CD12 T cell receptin
CD4
Factors that enhance an organism's ability to adhere to host tissues include __________. Peptidoglycan Adherence enzymes Fimbriae Lipoplysaccharide
Fimbriae
The most common circulating antibody, comprising about 80% of the serum immunoglobin, is IgG IgA IgC IgD
IgG
The dose of an antigen that kills 50% of animals in a test group and is used to estimate the virulence of a pathogen is known as Virulence- 50 Antigen dose 50 Death rate- 50 LD 50
LD 50
T cell receptors initiate an adaptive immune response by __________. Only binding when antigens are presented via MHC Only binding when antigens are free floating Having thousands of copies of the TCR proteins on the surface of a T cell Having multiple domains in their structure, including variable domains
Only binding when antigens are presented via MHC
Siderophores are Organic molecules that help pathogens take up iron Toxins that affect the gastrointestinal tract Molecules that aid directly in attachment to host cells Inorganic molecules that help in active transport
Organic molecules that help pathogens take up iron
The process by which white blood cells ingest and kill bacteria is called Exocytosis Phagocytosis Transcription Translation
Phagocytosis
The collective term for the organisms living on or in the human body, as opposed to a general term for organisms in an environmental habitat, is The microbiota The human microbiome pathogens transient microbial flora
The human microbiome
The condition that results when some bacteria are shed in the bloodstream and distributed to distant parts of the body but do not reproduce in the blood is called uremia septicemia bacteremia erythemia
bacteremia
The antigen-binding site of an antibody accommodates a small portion of the antigen called a(n) peptide motif PAMP epitope lipopolysaccharide
epitope
The part of the antigen recognized by the antibody or TCR is called the epitope antigen-binding site light chain anitgenic complex
epitope
Which of the following cell types has NO nucleus? phagocytes lymphocytes erythrocytes All of these lack a nucleus
erythrocytes
________ are toxic proteins released from the pathogen during normal growth. microtoxins macrotoxins exotoxins endotoxins
exotoxins
________ are cytotoxins produced by T cells that cause apoptosis. phagocytes macrophages granzymes perforins
granzymes
Substances that induce an immune response are known as antigens immunoglobins immunogens antigen-presenting cells
immunogens
Which of the following is most likely to cause disease? injection of 10^1 cells of a highly virulent bacterial species into a mouse injection of 10^6 cells of a low virulent bacterial species into a mouse injection of 10^3 cells of a moderately virulent bacterial species into a mouse injection of 10^5 cells of a highly virulent bacterial species into a mouse
injection of 10^5 cells of a highly virulent bacterial species into a mouse
The body's non-inducible, preexisting ability to recognize and destroy a variety of pathogens or their products is called innate immunity adaptive immunity cytotoxic response phagocytosis
innate immunity
Some intracellular pathogens produce phagocyte-killing proteins called ________ that kill the phagocyte after ingestion of the pathogen. pus anitbodies antigens leukocidins
leukocidins
Which of the following is NOT important for the adherence of bacteria to host tissues? slime layer capsule lipopolysaccharide adhesins
lipopolysaccharide
Which disease CANNOT be prevented via the use of a vaccine generated from an attenuated pathogen? measles rubella mumps malaria
malaria
MHC I proteins are found on macrophages only on B cells only on all nucleated cells on dendritic cells only
on all nucleated cells
The enhancement of phagocytosis due to deposition of antibody on the surface of a pathogen or antigen is called antibody class switching inflammation opsonization complementation
opsonization
Interaction of a PAMP with a TLR triggers transmembrane signal transduction and subsequent clonal expansion phagocytosis and inflammation antibody production complement protein activation
phagocytosis and inflammation
After the first exposure to an antigen, a ________ stimulates growth and multiplication of antigen-reaction cells. phagocytic immune response secondary innate immune response hyperactive cytotoxic response primary adaptive immune response
primary adaptive immune response
Capsules are particularly important for allowing bacteria to become more phagocytic making bacteria more vulnerable to host defense mechanisms protecting bacteria from host defense mechanisms making bacteria less pathogenic
protecting bacteria from host defense mechanisms
Staphylococcus aureus and Streptococcus pyogenes strains can produce ________ that cause the severe and sometimes life-threatening symptoms of toxic shock syndrome. endotoxin AB toxins cytolytic superantigen toxins
superantigen toxins
Which of the following is an example of a barrier defense that forms part of the innate immunity of vertebrates? Memory B cells B cells can become plasma cells and produce antibodies Cytotoxic T cells are activated when they interact with an antigen-presenting cell Acidity in the stomach kills many microbes
Acidity in the stomach kills many microbes
Oxygen compounds toxic in pathogens include hydrogen peroxide hypochlorus acid nitric oxide All of the above
All of the above
Virulence factors that enhance invasiveness of a pathogen can include __________. exotoxins coagulase collagenase all of the above
All of the above
Which of the following does NOT influence immunogenicity? foreign nature of the immunogen to the host solubility the routes of administration All of the above influence immunogenicity
All of the above influence immunogenicty
Which of the following does NOT affect pathogen growth? pH availability of microbial nutrients temperature All of these affect growth
All of these affect growth
Which of the following are intrinsic characteristics of immunogens? Appropriate physical form Being single compounds such as monomers Small molecular size Foreignness
Appropriate physical form
A pathogen must __________ in order for it to cause disease. Secrete a toxin Attach Enter a host Attach and multiply
Attach and multiply
Dimers of IgA are present in Breast milk colostrum Tears Saliva Breast milk colostrum, saliva, and tears
Breast milk colostrum, saliva, and tears
What is the difference between adherence and colonization? Colonization occurs when transient microbes are on a tissue, whereas adherence is a more permanent attachment to cells. Colonization occurs when a microbe begins to grow in host tissues whereas adherence occurs when the microbe initially attaches. Colonization occurs when microbes begin to spread in host tissues, whereas adherence occurs when microbes initially attach. Colonization occurs when microbes begin to spread in host tissues, whereas adherence occurs when microbes first begin to reproduce in the host tissues.
Colonization occurs when a microbe begins to grow in host tissues whereas adherence occurs when the microbe initially attaches.
Adaptive immunity occurs when A broad, rapid response is needed to a wide range of pathogens from the body regardless of a specific type of pathogen The innate immune response fails to eliminate pathogens in the body and virulent infections persist after the initial innate defense response. The innate immune response is overly effective. Death results from pathogen infection.
The innate immune response fails to eliminate pathogens in the body and virulent infections persist after the initial innate defense response.
Which of the following is a reason that specific pathogens tend to infect specific tissues? Microbes preferentially target external tissues, such as skin, as the environment is more favorable for their growth than inside the body. Tissues with neutral pH are colonized but those with acidic or alkaline pH are not. There are chemical and physical differences between tissues. Some tissues have receptors for microbes, but others do not.
There are chemical and physical differences between tissues.
Which of the following is a category of exotoxin? lipophilic toxin cytolytic toxin alpha-toxin beta-toxin
cytolytic toxin
