Microbial Interactions
Fiber is an example of a...
a. Gnotobiotic
b. Prebiotic
c. Protobiotic
d. Probiotic
e. Antibiotic
What is B, Prebiotic?
Distinct molecular patterns found on pathogenic microbes that are detected by host transmembrane receptors to trigger immune signaling are known as:
a. Opsonins
b. PRRs
c. TLRs
d. Epitopes
e. MAMPs
What is E, MAMPs?
The selective ability of a virus to infect certain cell types or tissues is referred to as:
a. Virulence
b. Tropism
c. Pathogenicity
d. Zoonosis
e. Infection
What is B, Tropism?
A public health researcher is studying a viral respiratory infection in a small tropical country. Over the past decade, she notices that a steady, predictable number of cases occur every year, mostly during the rainy season. The infection rarely spreads to other regions, and outbreaks are generally small and manageable by local healthcare facilities.
Which term best describes the pattern of this disease in the country?
a. Epidemic
b. Pandemic
c. Endemic
d. HAI
e. Outbreak
What is C, Endemic?
Prokaryotes:
a. Can be haploid or diploid
b. Use the protein parS to separate chromosomes
c. Generally prefer to live in hypertonic environments
d. Use the MinCDE system to find the center of the cell
e. Communicate through vertical gene transfer
What is D, Use the MinCDE system to find the center of the cell?
A team of environmental microbiologists is examining microbial interactions in a geothermal soil ecosystem. They observe that Microbe A secretes a siderophore that binds tightly to iron in the environment. Microbe B lacks the ability to produce siderophores but has evolved receptors that allow it to steal the iron-loaded siderophores produced by Microbe A. As a result, Microbe B grows more efficiently, while Microbe A’s growth rate decreases due to reduced iron availability.
What type of symbiotic relationship is occurring between Microbe A and Microbe B?
a. Mutualism
b. Commensalism
c. Parasitism
d. Amensalism
e. Competition
What is C, Parasitism?
What is the primary reason neutrophils undergo cell death at the site of infection?
a. Their nucleus collapses after repeated rounds of mitosis
b. The release of ROS damages the neutrophils themselves
c. They are eliminated by NK cells once the infection resolves
d. They die because pathogens consume all available nutrients
e. They cannot tolerate the slightly alkaline pH of inflamed tissues
What is B, The release of ROS damages the neutrophils themselves?
All of the following are true about leukocidins except:
a. It is produced by "super" Staphylococcus.
b. It is ineffective against red blood cells.
c. It is pyogenic, or pus-forming.
d. It is also referred to as "the spreading factor".
e. All of the above are true.
What is D, It is also referred to as "the spreading factor" ?
Salk's vaccine:
a. Was created to treat smallpox
b. Was not recommended for an immunocompromised patient
c. Was an mRNA vaccine
d. Used a live, attenuated virus to induce an immune response
e. Required boosters to maintain immunity
What is E, Required boosters to maintain immunity?
Archaea:
a. Are the only Domain of life that can produce all 20 amino acids
b. Have NAM-NAG in their cell wall
c. Have isoprene in their cell wall
d. Can have a monolayer or bilayer cell membrane
e. Can be broken down by lysozyme
What is D, Can have a monolayer or bilayer cell membrane?
Which of the following is NOT a mechanism carried out by microorganisms residing in the human body?
a. Releasing secreted toxins that inhibit the growth of neighboring bacteria without contact
b. Fermenting dietary carbohydrates to acidify the gut
c. Producing metabolites that interfere with host DNA repair, contributing to cancer development
d. Synthesizing propionate, which can influence host cholesterol metabolism
e. Generating cathelicidins that disrupt the membranes of pathogenic microbes
What is E, Generating cathelicidins that disrupt the membranes of pathogenic microbes?
Which of the following is an example of natural passive immunity?
a. Vaccination with a live, attenuated virus
b. Transfer of antibodies from mother to fetus via placenta
c. Production of antibodies after exposure to COVID
d. Injection of antiserum from another individual
e. Activation of T cells from a strep throat infection
What is B, Transfer of antibodies from mother to fetus via placenta?
Which of the following is correctly matched?
a. Lipid A- type of exotoxin
b. T3SS- removes YOPS from phagocytes, rendering them useless
c. Woolsorter's disease- type of disease caused by diphtheria toxin
d. Enterohemorrhagic E. coli- uses an AB toxin to induce bloody diarrhea
e. Cholera- uses TcdA and TcdB to disrupt tight junctions
What is D, Enterohemorrhagic E. coli- uses an AB toxin to induce bloody diarrhea?
All of the following are examples of primary metabolites except:
a. Pyruvate
b. PBPs
c. MreB
d. Glutamate
e. Bacitracin
What is E, Bacitracin?
The EM pathway:
a. Is the same as gluconeogenesis, but in reverse
b. Utilizes the enzyme RuBisCO
c. Is an oxidation reaction that produces a net of 4 ATP
d. Occurs in fermentation and respiration
e. Is a method that autotrophs use to fix carbon dioxide
What is D, Occurs in fermentation and respiration?
Short-chain fatty acids (SCFAs):
a. Are produced by Bifidobacteria
b. May have some influence on the central nervous system
c. Are used to recruit pro-inflammatory cytokines that induce intestinal inflammation
d. Both A & B
e. Both B & C
What is D, Both A & B?
The innate immune system:
a. Features granulocytes such as monocytes and mast cells, which release histamine in response to allergic reactions
b. Is bridged with adaptive immunity with the aid of dendrites
c. Includes some lymphocytes
d. Both A & B
e. All of the above
What is C, Includes some lymphocytes?
The bacterium that produces the tetanus toxin:
a. Is a Gram-positive spore former
b. Produces a toxin with a very high LD50
c. Blocks the release of glycine, resulting in spastic paralysis
d. Both A & C
e. All of the above
What is D, Both A & C?
Which of the following characteristics are used in a "good" antigen target?
a. Immunogenic
b. Intracellular
c. Found in certain strains
d. Both A & C
e. Both B & C
What is A, Immunogenic?
Which of the following is an example of a protein synthesis inhibitor?
a. Trimethoprim
b. Cephalosporin
c. Chloramphenicol
d. Both A & C
e. All of the above are protein synthesis inhibitors
What is C, Chloramphenicol?
Within the human body: (Select all that apply)
a. The skin is generally inhospitable to microbial growth because of its low salinity.
b. The human body hosts a wide variety of commensal bacterial species.
c. Microbial density increases along the gastrointestinal tract as the environment becomes progressively less acidic.
d. Eukaryotic microorganisms are absent from the normal human microbiota.
e. Urinary tract infections occur more frequently in men due to the structure of the male urethra.
What is B & C?
T cells: (Select all that apply)
a. Require an MHC to recognize antigenic peptides and activate into an effector cell
b. Are produced in larger quantities as you age
c. Use the thymus to encounter and bind to the antigen
d. Directly activate B cells with the help of TH17
e. Become effector cells that secrete antibodies such as IgG and IgM
What is A?
Enterotoxins: (Select all that apply)
a. Include CDT
b. Are produced by Gram-positives, but not Gram-negatives
c. Alter the permeability of the intestines
d. Are generally heat stable
e. May be directly ingested or produced during digestion
What are A, C, and E?
mRNA vaccines: (Select all that apply)
a. Are ineffective against eukaryotic diseases
b. Include the tetanus toxoid vaccine
c. May use an adjuvant to enhance the immune response
d. Can contribute to herd immunity
e. Introduces RNA directly into the host cell to be taken into the nucleus
What are C & D?
S. aureus: (Select all that apply)
a. Is part of the normal microbiota
b. Tests positive for coagulase
c. Uses Braun's lipoproteins
d. Has lysine in its peptidoglycan
e. Is a spore-forming bacterium
What are A, B, and D?