Exam 3: BIOS 242 / BIOS242 Review (Latest 2024/ 2025 Update) Fundamentals of Microbiology with Lab| Questions and Verified Answers| 100% Correct| Grade A- Chamberlain
Exam 3: BIOS 242 / BIOS242 Review (Latest
2024/ 2025 Update) Fundamentals of
Microbiology with Lab| Questions and
Verified Answers| 100% Correct| Grade AChamberlain
Q: what is an antigen?
Answer:
foreign molecule that causes a specific immune response
Q: what is another name for antigens?
Answer:
immunogens
Q: where do antigens come from?
Answer:
proteins and polysaccharides from cells and viruses
Q: what are the functions of plasmid cells?
Answer:
release antibodies into the tis- sue/blood, attach to antigens for destruction
Q: true or false: plasmid cells can produce 2000 antibodies per second
Answer:
true
Q: what is the percentage of neutrophils circulating WBC?
Answer:
55-90%
Q: what is the percentage of eosinophils circulating WBC?
Answer:
2-4%
Q: what is the percentage of basophils circulating WBC?
Answer:
less than 0.5%
Q: what is the percentage of lymphocytes circulating WBC?
Answer:
20-35%
Q: what is the percentage of monocytes circulating WBC?
Answer:
3-7%
Q: what is the function of neutrophils?
Answer:
production of toxic chemicals and phago- cytosis
Q: neutrophils react early in the response to bacteria, foreign materials, and damaged
tissue
Answer:
inflammatory
Q: a common sign of a bacterial infection is a high number of
Answer:
neutrophils
Q: what is the function of eosinophils?
Answer:
attack and destroy large eukaryotic pathogens
Q: which WBC is attracted to sites of parasitic infections?
Answer:
eosinophils
Q: elevation of eosinophil count occurs in and infections
Answer:
helminths, allergic
Q: what is the function of basophils?
Answer:
produce histamine and heparin
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the first line of defense is a surface protection composed of _ and barriers that keep microbes from penetrating sterile body compartments anatomical, physiological
the second line of defense is a and system that comes immediately into play if infectious agents make it past the surface defenses cellular, chemical
the third line of defense include that must be developed uniquely for each microbe through the action of specialized white blood cells specific host defenses the first line of defense includes physical and chemical barriers the second line of defense includes phagocytosis, inflammation, fever, antimicrobial proteins the third line of defense includes B and T cells what are the physical barriers on the skin? hair follicles, sweat glands, mucous membranes what are the chemical barriers of the skin? lysozyme, saliva, sweat, skin’s pH, hydrochloric acid, bile, resident microbiota what are the first lines of defense in the mouth? saliva (contains lysozyme) where do B cells mature? develop and mature in red bone marrow where do t cells mature? develop in bone marrow and mature in the thymus what is an antigen? foreign molecule that causes a specific immune response what is another name for antigens? immunogens where do antigens come from? proteins and polysaccharides from cells and viruses what are the functions of plasmid cells? release antibodies into the tissue/blood, attach to antigens for destruction true or false: plasmid cells can produce 2000 antibodies per second true what is the percentage of neutrophils circulating WBC? 55-90% what is the percentage of eosinophils circulating WBC? 2-4% what is the percentage of basophils circulating WBC? less than 0.5% what is the percentage of lymphocytes circulating WBC? 20-35% what is the percentage of monocytes circulating WBC? 3-7% what is the function of neutrophils? production of toxic chemicals and phagocytosis neutrophils react early in the response to bacteria, foreign materials, and damaged tissue inflammatory
a common sign of a bacterial infection is a high number of neutrophils
what is the function of eosinophils? attack and destroy large eukaryotic pathogens
which WBC is attracted to sites of parasitic infections? eosinophils
elevation of eosinophil count occurs in and infections helminths, allergic
what is the function of basophils? produce histamine and heparin
basophils mediate _ reactions allergic what are the two types of lymphocytes? B and T cells B cells form plasma cells that… produce antibodies what is the function of T cells kill foreign cells monocytes have a cytoplasm that hold granules containing digestive enzymes where are monocytes released from? bone marrow into blood stream _ are monocytes that have left blood circulation macrophages share morphological and functional characteristics of mast cells basophils
what is the function of t helper cell #1 (CD4) activates the cell mediated immunity pathway
what is the function of t helper cell #2 (CD4) activates macrophages to expel helminthsencourage tumor development
what is the function of t helper cell #17 (CD4) promotes inflammation
what is the function of t follicular helper cell (CD4, CD40) drives B-cell proliferationaids in B cell antibody switching
what is the function of t regulatory cell (CD25, CD4) controls specific immune responses
what is the function of t cytotoxic cell (CD8) destruction of infected host cells and other foreign cells
what is the function of gamma delta t cells react specifically and nonspecifically responsive to lipid antigens
what are the three main functional types of t cells? helper, regulatory, cytotoxic
how many antigen binding sites does a IgG monomer have? 2
how many antigen binding sites does a IgA dimer, monomer have? 4,2
how many antigen binding sites does a IgM pentamer have? 10
how many antigen binding sites does a IgD monomer have? 2
how many antigen binding sites does a IgE monomer have? 2
true or false: IgG can cross the placenta true
true or false: IgA can cross the placenta false
true or false: IgM can cross the placenta false
true or false: IgD can cross the placenta false
true or false: IgE can cross the placenta false
what is the biological function of IgG? long term immunity, memory antibodies
what is the biological function of IgA? secretory antibody, on mucous membranes
what is the biological function of IgM? produced at first response to antigen, serve as B-cell receptor
what is the biological function of IgD? receptor on B cells
what is the biological function of IgE? antibody of allergy; worm infections
what is natural immunity? acquired through the normal life experiences of a human and is not induced through medical means
what is natural active immunity? production of one’s own antibodies as a result of infection or natural exposure to antigen
what is natural passive immunity? result of prenatal and postnatal mother-child relationshipIgG antibodies are transported across placenta
what is artificial immunity? produced purposefully through medical procedures
what is artificial active immunity? vaccination
what is artificial passive immunity? immunotherapy
what is an example of natural active immunity? chicken pox
what is an example of natural passive immunity? breast milk
what is the role of the centers for disease control? tracking infectious diseases in the US
what is the gram reaction and shape of treponema pallidum? gram negative, spirochete shape
what is the gram reaction and shape of escherichia coli? gram negative, rod shape
shiga toxin producing e coli can cause hemolytic uremic syndrome
what is hemolytic uremic syndrome? severe hemolytic anemia that can cause kidney damage and failure
what is the gram reaction and shape of staphylococcus aureus? gram positive, grape like clusters
what is the gram reaction and shape of corynebacterium diphtheriae? gram positive, club shaped
what is the causative agent of scalded skin syndrome? s. aureus
what is the causative agent of MRSA impetigo? S. aureus, S. pyogenes
which organisms cause necrotizing fascitis? s. aureus, s. pyogenes
what are the signs and symptoms of measles infection? rash begins on head then spreads to body, koplik spots, fever, sore throat, conjunctivitis
what are Koplik spots? oral lesions in the mouth, tiny white dots surrounded by a ring of red
explain the relationship between human herpes virus 3, chicken pox, and shingles chicken pox is caused by HHV-3, and reactivation of HHV-3 causes shingles
what is the causative agent of trachoma? chlamydia trachomatis (chronic infection of the eye)
what does variant Creutfeldt- Jakob disease cause? transmissible spongiform encephalopathies
what are the signs and symptoms of a tetanus infection? clenching of the jaw, rigid paralysis, extreme arching of the back, flexion of the arms
death from tetanus results from paralysis of the respiratory muscles
what are the signs and symptoms of botulism? intoxication, prevents release of acetylcholine, resulting in flaccid paralysis
what is intoxication caused by in botulism? an exotoxin secreted by c. botulinum
what is flaccid paralysis? muscles cannot contract
what is viremia? viruses in the blood
what is fungemia? fungi in the blood
what is bacteremia? presence of bacteria in the blood
what is sepsis? bacteria flourishing and growing in the blood
decreased blood pressure leads to septic shock
what is the causative agent of lyme disease? Borrelia burgdorferi, evades the immune system by changing the surface antigens
what are the signs and symptoms of lyme disease? fever, stiff neck, headache, dizziness, bull’s eye rash
what is the causative agent of mononucleosis? epstein barr virus
what are the signs and symptoms of mononucleosis? sore throat, high fever, cervical lymphadenopathy, splenomegaly, fatigue
what are the complications that can result from stretococcus pyogenes infection? scarlet fever, rheumatic fever, glomerulonephritis
what is an antigenic drift? gradual changing of amino acid composition of influenza antigens
what does an antigen drift result in? decreased ability of host memory cells to recognize them
what is an antigenic shift? swapping out one of the strands of viral RNA with a gene or strand from another virus
what does antigenic shift result in? influenza pandemic
true or false: antigenic shift has no recognition by host memory cells true
what is the generation time of mycobacterium tuberculosis? 15-20 hours
how long does it take for colonies to appear for mycobacterium tuberculosis? 6 weeks
what is the shape of mycobacterium tuberculosis? long, thin acid-fast rod, strict aerobe
what is cord factor? lipid component in the mycobacterial cell wall associated with virulent strains
what is cord factor composed of ? mycolic acid and waxes
what does the cord factor make organisms resistant to? drying and disinfections
what is the gram stain of cord factors? gram positive
what does a mantoux test show? evidence of delayed hypersensitivity after initial infection with TB
what does mantoux test consist of? purified protein derivative injected under the skin and observed
what does a positive skin test for TB equal? induration (raised skin)
what is IGRA? blood test to determine T-cell reactivity to M. tuberculosis
what are two other methods for TB diagnosis? PCR methods, chest x-rays
what is the causative agent for TB? Mycobacterium tuberculosis
what are gastric or peptic ulcers? lesions in the mucosa of the stomach or uppermost portion of the small intestine
what is the causative agent for ulcers? helicobacter pylori
what kind of infection is helicobacter pylori? bacterial
what virulence factors does helicobacter pylori use? why? urease to raise the pH surrounding the bacteria
how is helicobacter pylori treated? tetracycline, antibiotic
what are the bacterial organisms that cause gastroenteritis salmonella, shigella, campylorbacter, e.coli, virbrio cholerae, STEC, clostridium difficile
what is the gram stain for clostridium difficile gram positive
what is the shape of clostridium difficile endospore forming rod found as normal biota of intestine
what does clostridium difficile cause? psuedomembranous colitis (antibiotic-associated colitis)
clostridium difficile overgrowth is caused by therapy with broad spectrum antibiotics
enter toxins A + B cause in the wall of the intestine and formation of pseudomembrane necrosis
what is the treatment for clostridium difficile ? withdrawal of antibiotics, replacement of fluids, metronidazole, fecal transplant
food poisoning is _ rather than infection intoxication what is the causative agent for vaginitis? treponema pallidum primary syphilis includes chancre what are chancre? small, red, hard bumps that appear at the site of the entry of the pathogen where does primary syphilis occur? internal/external genitalia, lips, oral cavity, nipples, fingers, anus tertiary syphilis includes gummas where do gummas develop? liver, skin, bone, cartilage congenital syphilis inhibits fetal growth and disrupts critical periods of development what can congenital syphilis cause? fetal abnormalities, spontaneous miscarriage or stillbirth when a newborn has congenital syphilis what do they profuse? nasal discharge tears and saliva contain lysozyme sweat contains high lactic acid what are the functions of helper t cells? activate macrophages, assist B cell process, and help activate cytotoxic t cells what are the functions of regulatory t cells? control the t cell response, act to control the inflammatory process, and prevent autoimmunity what are the functions of cytotoxic t cells? lead to teh destruction of infected host cells and other foreign cells what do CD8 cells secrete? perforins and granzymes why is heating food contaminated with S. aureus no guarantee that potential food poisoning will be prevented? if food is contaminated with staph, the bacteria can multiply and produce toxins. staph bacteria are killed by cooking but the toxins are not destroyed and will be able to cause illness what are the four signs and symptoms of inflammation? rubor, calor, tumor, dolor what is rubor? redness caused by an increased circulation and vasodilation what is calor? warmth from increased flow of blood what is tumor? swelling from increased fluid escaping from tissues what is dolor? pain caused by stimulation of nerve endings histamine is a _ mediator vasoactive what is histamine produced by? mast cells and basophils what does histamine cause? vasodilation, increased vascular permeability, and mucus production what is the main function of histamine? inflammation and allergies what are prostaglandins produced by? most body cells what do prostaglandins cause? dilation or constriction of blood vessels prostaglandins are powerful stimulants of inflammation and pain the humoral response involves b cells producing antibodies in response to an exogenous antigen what is an exogenous antigen? any antigen that is found outside the body where do b cells reside? tissues like lymph nodes how do b cells get exposed to pathogens in the body? lymphatic fluid drains through the lymph node cells participate in cell mediated immunity cytotoxic t cells
cell mediated immunity is directed at endogenous antigens endogenous antigens are found within the body cells ___ cells participate in humoral and cell mediated immunity helper t cells
helper t cells role is to enhance the response of b cells and cytotoxic t cells to an antigen
most b cells require stimulation from t cells
what types of cells are infected with HIV? helper t cells
destruction of helper t cells (CD4) would lead to an increase in the viral load, CD4 count decreases activating b cells and the levels rise above normal antibodies