Q&A Hero

Q: The essential protective role for T cell immunity is protection from A) viruses. B) extracellular pathogens. C) bacteria. D) intracellular pathogens.

Q: The transfer of antibodies through the placenta from mother to fetus is an example of A) natural passive immunity. B) innate immunity. C) natural active immunity. D) artificial active immunity.

Q: DiGeorge's syndrome is a developmental defect that prevents the maturation of the thymus. What cell type would be reduced by this condition? A) T cells B) B cells C) macrophages D) lymphocytes

Q: The inflammatory cytokines IL-1, IL-6, and TNF-α are also A) opsonizing agents that coat foreign cells. B) activating cytokines that stimulate Th1 cells to replicate. C) capable of producing systemic fever by stimulating the release of prostaglandins in the brain. D) part of the complement system that results in the destruction of foreign cells.

Q: A diagnostic test for M. tuberculosis exposure A) utilizes an inflammatory reaction that occurs if there has been previous exposure to M. tuberculosis antigens. B) relies on previous tuberculin vaccination. C) uses an antiserum to detect antibodies in the blood that are only formed if there has been previous exposure to M. tuberculosis antigens. D) relies on an innate immune response that occurs only if there has been previous exposure to M. tuberculosis antigens.

Q: After the first exposure to an antigen, a ________ stimulates growth and multiplication of antigen-reaction cells. A) secondary innate immune response B) primary adaptive immune response C) phagocytic immune response D) hyperactive cytotoxic response

Q: The first defense cells that interact with a pathogen in the body are A) T cells. B) macrophages. C) B cells. D) mast cells.

Q: The cells active in both innate and adaptive immunity develop from common pluripotent precursors in the bone marrow called A) B cells. B) killer cells. C) stem cells. D) leukocytes.

Q: Adaptive immune responses are directed at pathogen molecules called A) antigens. B) antibodies. C) T-cell receptors. D) PAMP.

Q: The body's non-inducible, preexisting ability to recognize and destroy pathogens or their products is called A) adaptive immunity. B) innate immunity. C) phagocytosis. D) cytotoxic response.

Q: All the following can cause contact dermatitis EXCEPT A) jewelry. B) latex gloves. C) poison ivy. D) superantigens.

Q: The life-threatening condition that may develop during a type I hypersensitivity reaction is called A) anaphylaxis. B) septic shock. C) stroke. D) toxic shock.

Q: Which of the following immunogens is MOST effective as a vaccine? A) chemically inactivated bacteria B) dead virus C) live virus D) toxoid

Q: New vaccine strategies resulting from progress in biochemistry and molecular biology include the production of A) DNA vaccines. B) recombinant vector vaccines. C) synthetic peptide vaccines. D) DNA, recombinant vector, and synthetic peptide vaccines.

Q: Which of the following diseases is/are associated with organ-specific autoimmune disease? A) autoimmune hypothyroidism B) juvenile (type I) diabetes C) systemic lupus erythematosus (SLE) D) autoimmune hypothyroidism and juvenile (type I) diabetes

Q: Systemic lupus erythematosus (SLE) is an example of a disease caused by type ________ hypersensitivity. A) I B) II C) III D) IV

Q: In Hashimotos's disease, autoantibodies are made against ________, a product of the thyroid gland. A) bacteria B) hemoglobin C) thyroglobulin D) viruses

Q: Type I hypersensitivity is caused by the release of vasoactive products from mast cells coated with A) IgA. B) IgE. C) IgG. D) IgM.

Q: An antigen must be at least ________ amino acids long to be effective in a vaccine. A) 10 B) 25 C) 50 D) 100

Q: Which of these is often used as a prophylactic measure to protect a person against future attack by a pathogen? A) antiserum injection B) artificial passive immunity C) vaccination D) None of these are correct.

Q: Which is an example of acquisition of natural passive immunity? A) a fetus protected from disease by its mother's antibodies B) a person who received his or her yearly influenza vaccine C) a person who acquired the chickenpox D) a person who received tetanus antiserum after stepping on a rusty nail

Q: Which of the treatments listed below would be MOST effective for a patient with a genetic defect that causes severe combined immunodeficiency (SCID)? A) intravenous antibiotics B) bone marrow transplant C) multiple immunizations D) repeated doses of antisera

Q: Phagocytes have general antibody receptors called ________ that bind to any antibody attached to an antigen. A) antigens B) antigen receptors C) Fc receptors D) membrane detectors

Q: Enhanced phagocytosis of antibody-sensitized cells is known as A) complementation. B) immunization. C) opsonization. D) tolerance.

Q: T cells interact with the peptide-MHC complex using A) cytokines. B) granzyme and perforin. C) T-cell receptors. D) the antibodies present on the surface of the cell.

Q: IgG, IgM, and IgA are examples of ________ found in blood. A) antibodies B) antigens C) bacteria D) pathogens

Q: Which of the following are molecular mediators of inflammation? A) chemokines B) cytokines C) erythrocytes D) both chemokines and cytokines

Q: The process by which antibodies block interactions between pathogens or their products and host cells is termed A) attenuation. B) complement. C) interference. D) neutralization.

Q: An example of pathogen-associated molecular patterns (PAMP) is A) cell-surface proteins. B) flagellin proteins. C) lipopolysaccharide (LPS). D) pilus.

Q: The rapid increase in adaptive immunity after a second antigen exposure is called A) immune memory. B) specificity. C) tolerance. D) immune memory, specificity, or tolerance.

Q: The unique antigen-reactive proteins of T cells are A) antibodies. B) immunoglobins. C) T cell receptors. D) None of these is correct.

Q: Which of the following can cause allergy symptoms and inflammation by degranulation? A) dendritic cells B) erythrocytes C) macrophage D) polymorphonuclear leukocyte

Q: The secondary lymphoid organs consist of the following EXCEPT A) lymph nodes. B) mucosal-associated lymphoid tissue (MALT). C) spleen. D) All of these organs are secondary lymphoid organs.

Q: Which of the following cell types has NO nucleus? A) erythrocytes B) lymphocytes C) phagocyte D) All of these cells lack a nucleus.

Q: Which of the following is TRUE about cytokines? A) They are proteins. B) They play an important role in immunity. C) They play a role in the growth of stem cells. D) They are proteins that play an important role in immunity and the growth of stem cells.

Q: Stem cells are produced and developed in the A) bone marrow. B) brain. C) liver. D) stems of plants.

Q: Blood and lymph have the following in common EXCEPT A) nucleated cells. B) proteins. C) red blood cells. D) none of these

Q: Adaptive immunity occurs when A) death results from pathogen infection. B) the innate immune response fails to eliminate pathogens in the body. C) virulent pathogen infections persist in the body after the initial innate defense response. D) the innate immune response fails to eliminate pathogens in the body and virulent infections persist after the initial innate defense response.

Q: Cells that can engulf foreign particles, and can ingest, kill, and digest most bacterial pathogens are called A) red blood cells. B) phagocytes. C) reticulocytes. D) resistant cells.

Q: The ability of humans to resist a disease is called A) dormancy. B) immunity. C) resistance. D) susceptibility.

Q: Why is fever the universal result of endotoxin exposure?

Q: What are the different categories of exotoxins, and how do they function?

Q: Describe the difference between the use of streptokinase and coagulase as a defense mechanism among pathogens.

Q: Explain how Clostridium tetani cells that rarely leave their initial site of infection can cause death in their hosts.

Q: What is the difference between pathogenic and non-pathogenic E. coli in relation to the human host?

Q: Why does Neisseria gonorrhea adhere only to mucosal epithelial cells in the genitourinary tract, eye, rectum, and throat?

Q: What is the similarity between the flora found in a female at the menopause stage and a female at the pre-puberty stage? How different is it from a female between the stages of puberty and menopause?

Q: Describe how orally taken antibiotics can result in the harmful alteration in digestive functions and disease.

Q: How do dental lactic acid bacteria cause dental caries?

Q: Design an experiment to determine whether a potential pathogen produces hemolysins.

Q: When does an infection become a disease?

Q: Why are some microorganisms specialized to only certain parts of the body? Describe an example that supports your answer.

Q: Explain how diet plays a role in host susceptibility to infection.

Q: Clostridium botulinum cannot produce toxins in improperly preserved foods.

Q: Diphtheria toxin inactivates elongation factor 2 by catalyzing the attachment of adenosine diphosphate ribose from NAD+.

Q: Animals that lack CXCR4 and CCR5 proteins are immune to HIV infection.

Q: Clostridium botulinum are endospore-forming bacteria normally found in the soil.

Q: The number of Vibrio cholera cells necessary to produce cholera in an exposed individual is drastically reduced if the individual is malnourished.

Q: Hormones that are produced under stress boost normal immune responses and play a role in stress-mediated disease resistance.

Q: Gram-positive bacteria produce endotoxins.

Q: The Limulus amebocyte lysate assay is used to detect endotoxin in clinical samples such as serum or cerebrospinal fluid.

Q: Endotoxins are released in large amounts only when cells lyse.

Q: The toxic lipopolysaccharides produced by MOST gram-negative bacteria are called exotoxins.

Q: Invasion is the ability of a pathogen to enter into host cells or tissues, spread, and cause disease.

Q: R plasmids help prevent the spread of virulence factors.

Q: Vaginal acidity in the adult female is due to acid production by Lactobacillus acidophilus.

Q: The upper respiratory tract usually has a considerable amount of resident microflora in a healthy adult.

Q: Malassezia spp. are the MOST common fungi present on the skin of humans.

Q: Bacteria make up about one-third the weight of fecal matter.

Q: Protists are NOT normally found in the gastrointestinal tract of healthy individuals.

Q: Cholera begins following a bite from a mosquito.

Q: Pathogen virulence NEVER changes throughout a host's life.

Q: Streptococcus mutans can produce dextran when sucrose is present in the absence of the enzyme dextransucrase.

Q: Virulence refers to the ability of an organism to cause disease.

Q: Normal microflora are usually found in the blood, lymph, and nervous systems of the body.

Q: An opportunistic pathogen causes disease ONLY in the presence of normal host resistance.

Q: Bacteria found in the mouth in the first years of life are well-adapted to biofilm formation.

Q: ALL microorganisms that live in the human body are harmful.

Q: ________ are microbial infections acquired by hospital patients with noninfectious diseases because they are compromised hosts. A) Healthcare-associated infections B) Immunocompromised infections C) Pathogenic infections D) Virulent infections

Q: Which of the following is a category of exotoxin?A) cytolytic toxinB) lipophilic toxinC) -toxinD) -toxin