BIO 208 UK Microbiology: FINAL EXAM
Each of the following will result in complement activation
-Antibody binding to antigen. -All of these will result in activation of complement. -lectin binding to mannose on the surface of the microbe. -recognition of lipid-carbohydrate molecules on the surface of the microbe.
cell-mediated immunity (cellular immunity)
-Any adaptive immune response in which antigen-specific effector T cells dominate. -It is defined operationally as all adaptive immunity that cannot be transferred to a naive recipient with serum antibody. -Activates cytokines. -Cell-mediated immune responses include CD4+ T cell-mediated activation of macrophages that have phagocytosed microbes and CD8+ cytolytic T lymphocyte killing of infected cells.
What do aerobic respiration and anaerobic respiration have in common?
-Between 2 and 38 molecules of ATP are produced per molecule of glucose input. -Process involves the electron transport system
Which of the following is a defense of the genitourinary tract?
-Flushing action of urine -Lysozyme -Mucus secretions -IgA
Human breast milk contains lactoferrin, lysozyme, secretory IgA, IgG, and complement C3. Identify the presence of innate and adaptive immune defenses.
-Innate defenses: lactoferring, lysoszyme, complement C3 -Adaptive defenses: secretory IgA, IgG
Which of the following statements about Neisseria meningitidis is TRUE?
-It can infect the meninges and causes the condition meningitis. -It is prevented by immunization or treated with antibiotics. -Signs/symptoms include photophobia, stiff neck, and fever. -It normally colonizes the upper respiratory tract of some people.
Which of the following statements about Neisseria meningitidis is TRUE?
-It is encapsulated. -A healthy carrier state can exist. -It is typically transmitted by droplet aerosols or direct contact with secretions. -It produces IgA protease.
Which of the following statements about salmonellosis is TRUE?
-It is often associated with poultry products. -It is a self-limiting infection. -A healthy carrier state exists. -It is a bacterial infection.
Secretory IgA dimer
-Neutralization and trapping of pathogens in mucus. -13% (monomer) of total antibody in serum -does not cross placenta -fixes compliment
IgM pentamer
-Neutralization, agglutination, and compliment activation. the monomer form serves as the B-cell receptor. -6% of total antibody in serum -does not cross placenta -fixes compliment
IgG monomer
-Neutralization, agglutination, compliment activation, opsonization, and antibody-dependent cell-mediated cytotoxicity. -80% of total antibody in serum -crosses placenta -fixes compliment -Fc binds to phagocytes
Which of the following is a mechanism of defense against microbial infection in the skin?
-Release of dead skin cells from the epidermis. -Secretion of sebum and lysozyme to inhibits the growth of microbes. -Tightly packed epithelial cells that create an impenetrable barrier.
Which of the following is a way that the complement system helps to fight infections?
-The microbe is coated in complement proteins, which enhances phagocytosis. -Inflammatory molecules are released. -The membrane attack complex leads to microbe bursting. -Chemotactic signals bring phagocytes to the area.
Functions of antibodies
-They can prevent viral attachment to a host cell -They can facilitate phagocyte attack on a bacteria -They can inactivate toxins released by pathogens -They can bind more than one pathogen at a time, forming complexes
Why are viruses considered nonliving?
-Viruses contain DNA or RNA but not both -Viruses require a host cell to reproduce
Why is it more difficult to treat viral infections than it is to treat bacterial infections?
-Viruses use the host cell's processes to carry out their own reproduction. -It is difficult to achieve selective toxicity with antiviral medicines.
antigen processing
-breaking an antigen into smaller molecules -EAPCs bring antigen into their intracellular space and then break it down into smaller molecules -human cells infected with an intracellular antigen will break it down into smaller molecules
Minimum Bactericidal Concentration (MBC) test
-determines the lowest antibacterial drug concentration that kills 99.9% of the starting culture -lowest dilution that inhibits turbidity (cloudiness indicating microbial growth)
antigen presentation
-follows antigen processing -one of the smaller molecules of the antigen is bound to an MHC receptor -the MCH receptor with the small piece of antigen bound to it is displayed on the surface of the cell -EAPCs present extracellular antigens on MHC II -infected human cells present intracellular antigens on MHC I
humoral immunity
-specific immunity produced by B cells that produce antibodies that circulate in extracellular body fluids -the end result of activation is the differentiation of plasma B-cells, secreting antibodies
The lower respiratory tract is protected by
-the ciliary escalator. -IgA antibodies. -mucous secretions. -alveolar macrophages.
Steps of B cell activation
1. B cell receptor on surface of B cells binds to antigen on the surface of an extracellular pathogen. 2. Antigen-antibody complex is internalized and processed. 3. Antigen breakdown products bind major histocompatibility complex protein and are "displayed" on B cell surface. 4. B cell is activated to divide and differentiate into plasma cells and memory cells.
steps of aerobic respiration
1. Glycolysis 2. Krebs Cycle 3. Electron Transport Chain
steps of lysogenic cycle
1. attachment 2. penetration 3. integration 4. replication
steps of lytic cycle
1. phage attaches to host cell and injects its viral DNA 2. phage DNA circularizes 3. new phage DNA and proteins are synthesized 4. assembly of phage inside host cell 5. cell lyses, releasing new phages
What will be the result of conjugation between an F+ and an F- bacteria cell?
2 F+ bacteria cells
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people as a result of Coxiella burnettii infections. Before the outbreak, 2000 sheep were kept 30 miles northwest of the town, 95% of sheep tested were positive for C. burnetii. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years. In situation 14.1 what is the incidence of pneumonia in humans for the six-month period?
239/300 = 77%
Place the following in the order in which they are found inside a host cell: (1) capsid proteins; (2) infective bacteriophage; (3) bacteriophage nucleic acid.
3, 1, 2
At the start of 2015, 36.5 million people were living with HIV in the world. If 2 million people contract HIV and 1 million people died of HIV in 2015, what was the prevalence of HIV in the world at the end of 2015? (Assume the world population at the end of 2015 was 7.5 billion)
37.5 million/7.5 billion
Refer to Figure 1. Where did airborne microbes end up in the swan-necked flask use in Pasteur's experiment?
4
Place the phases of phagocytosis in the correct order: 1 - Ingestion of microbe by phagocyte 2 - Digestion of microbe by enzymes 3 - Discharge of waste materials 4 - Chemotaxis and adherence 5 - Formation of phagolysosome
4,1,5,2,3
A patient with HIV is most contagious when the concentration of viral RNA copies in the blood is highest. Figure 2 shows an example of HIV progression in a patient. Identify the time points when this patient is most contagious?
7 weeks after infection
Antimicrobial drugs that target protein synthesis in bacteria will affect the _____ ribosome present in the _____.
70s, prokaryotic cell cytoplasm and eukaryotic cell mitochondria
Which of the following statements regarding gonorrhea is incorrect?
A lesion develops at the portal of entry.
B cell
A lymphocyte that produces proteins that help destroy pathogens.
prophage
A phage genome that has been inserted into a specific site on the bacterial chromosome.
lysogenic cycle
A phage replication cycle in which the viral genome becomes incorporated into the bacterial host chromosome as a prophage and does not kill the host.
virulent phage
A phage that reproduces only by a lytic cycle.
Describe ATP production by ATP synthase.
A proton gradient allows hydrogen ions (H+ ions) to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP.
Endospore
A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions.
enzyme
A type of protein that speeds up a chemical reaction in a living thing
lytic cycle
A type of viral (phage) replication cycle resulting in the release of new phages by lysis (and death) of the host cell.
provirus
A viral genome that is permanently inserted into a host genome.
bacteriophage/phage
A virus that infects bacteria
Each of the following is an effect of complement activation EXCEPT A) Activation of peristalsis. B) bacterial cell lysis. C) opsonization. D) increased phagocytic activity. E) inflammation.
A) Activation of peristalsis.
Which is TRUE of Beta-lactamases? A) Beta-lactamases are made by bacteria B) Beta-lactamases can inactivate B-lactam drugs C) Beta-lactamases are made by humans and other mammals D) Beta-lactamases can be inactivated by chemicals
A) Beta-lactamases are made by bacteria B) Beta-lactamases can inactivate B-lactam drugs D) Beta-lactamases can be inactivated by chemicals
There are three domains in the phylogenetic tree of life; Bacteria, Archaea, and Eukarya. Which microbe group is matched correctly with its domain? A) Fungi are in the domain Eukarya B) Algae are in the domain Bacteria C) Helminths are in the domain Archaea D) Protozoa are in the domain Bacteria E) Viruses are in the domain Eukarya
A) Fungi are in the domain Eukarya
Select the diagnostic test for MRSA that is described correctly. A) Gram stain - to identify cell wall structures that are present in S. aureus. B) Blood agar - bacterial growth on this petri dish demonstrates that the microbe can produce enzyme for making blood clot. C) Coagulase test - microbes able to produce coagulase will cause the liquid plasma to change color. D) Mannitol salt agar - S. aureus will not grow on this type of media.
A) Gram stain - to identify cell wall structures that are present in S. aureus.
Which of the following is true? A) It is possible to be infected with HIV without having AIDS. B) It is impossible to have HIV and AIDS at the same time. C) It is possible to have AIDS without being infected with HIV. D) Patients who are HIV positive but are not actively ill are not able to infect others.
A) It is possible to be infected with HIV without having AIDS.
Which of the following statements about sepsis is FALSE? A) It usually is caused by gram-negative bacteria. B) It can be treated with antibiotics. C) Lymphangitis may occur. D) Symptoms include fever and decreased blood pressure. E) It may be aggravated by antibiotics.
A) It usually is caused by gram-negative bacteria.
Each of the following will result in complement activation EXCEPT A) TLR binding to PAMP on the microbe. B) recognition of lectin molecules on the surface of the microbe. C) antibody binding to antigen. D) All of these will result in activation of complement.
A) TLR binding to PAMP on the microbe.
Which of the following is the best definition of infection? A) The ability of a microbe to get into a host, survive, and multiply. B) The cause of a disease. C) The interactions between a host and a pathogen. D) A microbe's ability to cause disease in a host.
A) The ability of a microbe to get into a host, survive, and multiply.
Which of the following is incorrect regarding Yersinia pestis? A) The only reservoir of Y. pestis is humans. B) It may lead to shock as a results of endotoxin production. C) It is a gram-negative rod. D) It's presence in the patient can diagnosed by culturing the blood to check for growth of Y. pestis. E) It can grow in the lymphatic system, lungs, or blood.
A) The only reservoir of Y. pestis is humans.
Which of the following is NOT true regarding healthcare-associated infections? A) These infections are only transmitted by medical personnel. B) These infections often involve the patient's urinary tract and surgical incisions. C) The patient's resident biota can be the infectious agent. D) Escherichia coli and staphylococci are common infectious agents. E) Medical and surgical asepsis help lower their occurrence.
A) These infections are only transmitted by medical personnel.
1. Which symptom is NOT commonly associated with chronic gonorrhea in women? A) amenorrhea (lack of menstruation) B) increased menstrual flow C) pelvic pain D) vaginal discharge E) painful urination
A) amenorrhea (lack of menstruation)
Identify which pathogen is the least virulent on the basis of ID50. A) pathogen A with an ID50 of 1000 cells B) pathogen B with an ID50 of 50 cells C) pathogen C with an ID50 of 1 cell D) pathogenicity cannot be determined from ID50 values
A) pathogen A with an ID50 of 1000 cells
In Figure 6.3, which organisms possess at least one of the enzymes necessary for detoxifying oxygen?
A, C, D, and E
What is a product of the Krebs cycle?
ATP, NADH, and FADH2
MHC I
All nucleated cells express MHC I
vaccination
An injection that produces a mild form of a disease in order to help build up an immunity to it.
Which person would likely have the most mild disease following an Epstein-Barr infection?
An otherwise healthy toddler.
Which of the following is a reason that microbes in a biofilm are more resistant to antibiotics than free-floating microbes?
Antibiotics can't diffuse through the biofilm so can't reach most microbes AND The biofilm can disperse to secondary sites.
What is meant by selective toxicity?
Antimicrobial treatments should act against the microbial pathogen and not the host.
Thermophiles
Archaea that thrive in very hot environments, such as volcanic springs.
In Figure 3, which diagram shows a Gram-negative cell wall?
B
What kind of cells can present antigens from extracellular pathogens on Class II MHC proteins?
B cells or Macrophages
In Figure 6.3, which organisms do NOT possess enzymes necessary for detoxifying oxygen?
B only
Which of the following forms of metabolism produces the most energy per molecule of glucose? A) Anaerobic respiration B) Aerobic respiration C) Lactic acid fermentation D) Alcohol fermentation
B) Aerobic respiration
1. Which of the following is NOT a protective characteristics of urine? A) Acidic pH B) Contains mucus C) Contains lysozyme which breaks down peptidoglycan D) Contains lactoferrin, an iron-binding protein E) Contains secrectory IgA
B) Contains mucus
Which of the following is generally NOT a necessary step in the virus cycle of reproduction? A) Virus binds to host cell. B) Virus incorporates its DNA into its host's DNA. C) New virus parts are made and assembled in the host cell. D) Virus exits the cell (by either lysis or budding).
B) Virus incorporates its DNA into its host's DNA.
After penetration, animal viruses need to be uncoated by bacteriophage need not be. Why?
Bacteriophage inject their DNA into the host during penetration so the capsid doesn't enter the host cell
Which of the following statements about Neisseria meningitidis is FALSE?
Before starting treatment, it is important to culture a patient sample to confirm that the bacteria is present in the cerebrospinal fluid.
In what two ways can the plague be transmitted?
Biological and droplet
You work at a small family practice. A man in their early fifties comes in with a complaint of intermittent fever and a minor headache. You are the physician that examines them and the only clinical finding is a wound on their thumb that does not appear infected and which they received while skinning a ground squirrel about three days ago. The patient also has several small bug bites, also not appearing infected, around the wrist of the hand with the wound. The lymph nodes at their neck are swollen but inside their throat looks normal and there are no other visible signs of illness. The patient is up to date on their vaccinations and also received the recommended shingles and influenza vaccines earlier this year. The patient has not been in contact with anyone known to be ill with an infection. What patient samples would you request immediately for testing?
Blood draw
Which describes the genome of a prokaryotic cell? A) Circular RNA that is located in a membrane-bound nucleus. B) Linear DNA located in the nucleoid in the cytoplasm. C) Circular DNA located in the nucleoid in the cytoplasm. D) Linear DNA located in a membrane-bound nucleus.
C) Circular DNA located in the nucleoid in the cytoplasm.
Which of the following is a correct usage of binomial nomenclature? A) Helicobacter pylori B) helicobacter pylori C) Helicobacter pylori D) Helicobacter Pylori E) Helicobacter p.
C) Helicobacter pylori
Which cell can transfer the most DNA? A) F+ cell B) F-cell C) Hfr cell D) R cell E) B cell
C) Hfr cell
Which of the following is NOT a way that the complement system helps to fight infections? A) The microbe is coated in complement proteins, which enhances phagocytosis. B) The membrane attack complex leads to microbe bursting. C) Infected cells are forced to undergo apoptosis. D) Chemotactic signals bring phagocytes to the area. E) Inflammatory molecules are released.
C) Infected cells are forced to undergo apoptosis.
Which of the following statements about Neisseria meningitidis is FALSE? A) It is encapsulated. B) It is typically transmitted by droplet aerosols or direct contact with secretions. C) It is a gram-positive anaerobe. D) A healthy carrier state can exist. E) It produces IgA protease.
C) It is a gram-positive anaerobe.
All of the following are physical barriers to pathogens, except ______. A) hairs B) unbroken skin C) T-cells D) tears E) mucous
C) T-cells
Which statement correctly describes the eukaryotic and prokaryotic ribosome? A) The eukaryotic ribosome is located only in the cytoplasm while the prokaryotic ribosome is located in the cytoplasm and in some of the cell's organelles. B) The eukaryotic ribosome makes mRNA and the prokaryotic ribosome makes protein. C) The ribosome in the eukaryotic cell cytoplasm is larger than the prokaryotic ribosome. D) The ribosome in the eukaryotic cell mitochondria is larger than the ribosome in the prokaryotic cell. E) Drugs that target the prokaryotic cell ribosome will have no effect on a eukaryotic cell.
C) The ribosome in the eukaryotic cell cytoplasm is larger than the prokaryotic ribosome.
Which of the following statements regarding antibody function is FALSE? A) They can prevent viral attachment to a host cell B) They can facilitate phagocyte attack on a bacteria C) They can penetrate host cells to bind intracellular antigens D) They can inactivate toxins released by pathogens E) They can bind more than one pathogen at a time, forming complexes
C) They can penetrate host cells to bind intracellular antigens
Which of the following statements about normal microbiota is TRUE? A) They are present in all sites in the body. B) They are acquired late in life. C) They prevent infection leading to disease by microbial antagonism. D) They encourage growth of pathogenic microbes.
C) They prevent infection leading to disease by microbial antagonism.
The vaccine for botulism involves injection of the toxin produced by C. botulinum that has been chemically detoxified. Which of the following statements below is TRUE? A) The vaccine mounts a secondary immune response. B) Immunity from the vaccine is passive. C) This is a toxoid vaccine. D) You can still get botulism after receiving the botulism vaccine.
C) This is a toxoid vaccine.
If an individual has a genetic disorder whereby they lack the ability to make complement proteins, the likely consequence is A) excessive fever development. B) enhanced inflammation. C) a higher incidence of bacterial and viral infections. D) an inability to synthesize antibodies.
C) a higher incidence of bacterial and viral infections.
Epstein-Barr virus has been implicated in all of the following EXCEPT A) infectious mononucleosis. B) Hodgkin's lymphoma. C) gastritis. D) oral hair leukoplakia. E) Burkitt's lymphoma.
C) gastritis.
Glycolysis formula
C6H12O6 + 2 ATP (start up energy) → 2 pyruvic acid (a 3 C compound) + 4 ATP (a gain of 2 ATP)
What is oxidized in the following reaction? C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O
C6H12O6 is oxidized to CO2
What is the electron donor and what is the electron acceptor in the following reaction? C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O
C6H12O6 is the electron donor O2 is the electron acceptor
Refer to Figure 1. Which of the following statements regarding the development of AIDS following infection with HIV is INCORRECT?
CD4 T cells are present in low numbers in an uninfected individual, but become elevated upon HIV infection, and ultimately fall to very low numbers as the infection progresses to AIDS.
As the Covid-19 pandemic spreads, healthcare systems in all parts of the world are being overwhelmed because there aren't enough medical workers and medical equipment to support patients with Covid. This is leading to an increase in fatalities among Covid patients from an estimated 2-3% at the start of the pandemic to ~5.5% currently. This represents an increase in the _____ of Covid-19.
CFR
Pathogenic Staphylococcus produce coagulase and testing for production of this enzyme can help to diagnose Staphylococcal diseases like MRSA. How does coagulase aid Staphyloccocus in infecting host tissues?
Coagulase causes the blood to clot, which provides a place for the bacteria to hide from immune cells.
anabolism
Constructive metabolism requires energy; the process of building up larger molecules from smaller ones.
What is required for a B cell to differentiate into a plasma cell?
Cytokines released by a CD4+ T cell after the B cell displays an antigen AND The B cell receptor binds to antigen.
CD8
Cytotoxic T cells
Which of the following is NOT a way that the complement system helps to fight infections?
Cytotoxicity causes infected cells to undergo apoptosis.
In Figure 6.3, which organisms can tolerate oxygen but CANNOT perform aerobic respiration?
D
Which of the following reactions would require ATP in order to occur? A) Breaking down a large molecule of DNA into individual nucleotides. B) Any catabolic reaction. C) Removing a sugar from a long polysaccharide chain. D) Binding several amino acids into a larger, protein molecule.
D) Binding several amino acids into a larger, protein molecule.
Which of these molecules carry high-energy electrons from the citric acid cycle to the electron transport chain? A) NAD+ B) NADH C) FADH2 D) Both B and C
D) Both B and C
Which of these molecules carry high-energy electrons from the Krebs cycle to the electron transport chain? A) NAD+ B) NADH C) FADH2 D) Both NADH and FADH2
D) Both NADH and FADH2
Which of the following statements about salmonellosis is FALSE? A) It is a bacterial infection. B) Severity of disease depends on number of organisms ingested. C) A healthy carrier state exists. D) The mortality rate is high. E) It is often associated with poultry products.
D) The mortality rate is high.
One reason that the skin is inhospitable to microbes is that: A) It has a neutral pH, which prevents growth by most species of microbes. B) It lacks salt, which is an essential nutrient for microbe growth. C) It is relatively moist and this inhibits their growth. D) The normal microbiota outcompetes other microbes and inhibits their growth.
D) The normal microbiota outcompetes other microbes and inhibits their growth.
All of the following are events of inflammation except A) macrophages begin phagocytosis. B) chemical signals recruit leukoctyes to the area of infection. C) brief vasoconstriction is followed by vasodilation. D) exoenzymes degrade cell connections to enable invastion. E) capillaries become more permeable.
D) exoenzymes degrade cell connections to enable invastion.
Which of the following cell characteristics is present in the domain Bacteria? A) have 80S ribosomes as the major ribosome type B) cells are part of a multicellular organism C) are never pathogenic D) have peptidoglycan cell walls E) are capable of decomposing organic matter
D) have peptidoglycan cell walls
Which is the best term to describe the process that occurs when an immune cell releases cytokines to nearby cells to trigger a response? A) autocrine B) endocrine C) hormonal D) paracrine
D) paracrine
Which of the following is the initial compartment a pathogen enters after being engulfed by a macrophage? A) inclusion B) lysosome C) phagolysosome D) phagosome
D) phagosome
Innate immunity includes all of the following EXCEPT A) phagocytosis. B) inflammation. C) fever. D) production of antibody.
D) production of antibody.
The mucociliary escalator effect helps to do which of the following? A) localize microbes in specific parts of the respiratory tract, enhancing the immune response against them and reducing the risk that they will be exhaled B) move air through the respiratory tract C) move pathogens deeper into the respiratory tract, where macrophages can engulf them D) remove pathogens from the respiratory tract, eliminating microbes from the lower respiratory tract, and inhibiting pathogen attachment
D) remove pathogens from the respiratory tract, eliminating microbes from the lower respiratory tract, and inhibiting pathogen attachment
Transduction in bacteria
DNA is transferred from one bacteria to another by a virus
Which of the following describe a virus outside of a host cell?
DNA or RNA genome surrounded by a capsid AND Inactive.
1. Errors in the activity of _____ would probably have the most significant effect on the number of mutations in the bacterial cell genome.
DNA polymerase III
What single resistance mechanism has the potential to target the broadest range of drugs?
Development of nonspecific efflux pumps
serial dilution
Dilution of a substance several times by the same amount each time
DNA transfer by conjugation is more efficient in a liquid medium setting, subjected to very mild agitation (stirring), rather than on an agar plate format. Why?
Direct cell-to-cell contact is required for this process, and this is more likely to be achieved in the fluid liquid format than on an agar plate (especially for relatively non-motile types of bacteria).
Which of the following statements describes the period of illness in the progression of infectious disease?
During this period, the infected individual exhibits obvious signs of sickness.
Which of the following is an extracellular antigen? A) A bacterium inside a cell B) A virus inside a cell C) An uninfected human cell D) The malaria parasite inside a red blood cell E) A bacterium outside a cell
E) A bacterium outside a cell
Colonization of the body is inhibited by A) the shedding of skin cells. B) the movement of mucus by cilia. C) peristalsis. D) the flushing action of the urinary tract. E) All of the choices are correct.
E) All of the choices are correct.
Reservoirs include _____. A) humans B) animals C) soil D) water E) All of the choices are correct.
E) All of the choices are correct.
Which of the following may be considered a virulence factor? A) Hyaluronidase B) Capsules C) Endotoxins D) Proteases E) All of the choices are correct.
E) All of the choices are correct.
Vibrio cholera produces cholera toxin that causes release of ions into the intestinal lumen and leads to A) diarrhea. B) rice water stools. C) release of water into the lumen as well. D) severe dehydration. E) All of these answers occur as a result of cholera toxin.
E) All of these answers occur as a result of cholera toxin.
Neisseria gonorrhoeae is A) can cause eye infections in babies born of infected mothers. B) the cause of gonorrhea. C) virulent due to fimbriae and a protease that inactivates IgA. D) called the gonococcus. E) All of these choices are correct.
E) All of these choices are correct.
Which statement about horizontal gene transfer is associated with conjugation? A) This mechanism may result in the transfer of genes that encode antibiotic resistance. B) This mechanism requires direct cell-to-cell contact. C) This mechanism of genetic transfer always involves a one-way transfer from a donor cell to a recipient cell. D) This mechanism is initiated by cells with F plasmids. E) All of these statements are associated with conjugation.
E) All of these statements are associated with conjugation.
Which of the following is NOT true of an organism's genotype? A) It contains structural genes that code for proteins. B) It has regulatory genes that control gene expression. C) It contains genes that code for RNA. D) It is inherited. E) It has expressed traits governed by the genes.
E) It has expressed traits governed by the genes.
Which of the following is not part of the lower respiratory system? A) Alveoli B) Bronchi C) Bronchioles D) Trachea E) Sinuses
E) Sinuses
Which of the following is a fomite? A) water B) droplets from a sneeze C) pus D) insects E) a hypodermic needle
E) a hypodermic needle
Microorganisms are essential to our life. Each of the following is an example of a beneficial function of microorganisms EXCEPT A) making beer. B) making cheese. C) bioremediation. D) aiding human digestion. E) increased fertility.
E) increased fertility.
Which of the following is likely to spread MRSA among athletes? A) shared equipment B) physical contact C) vehicle transmission D) asymptomatic carriers E) shared equipment AND physical contact
E) shared equipment AND physical contact
You have taken E. coli strain A, which has its own plasmids, and mixed it with E. coli strain B without plasmids. E. coli strain B cells now have plasmids but in addition, they also carry some genes from E. coli strain A. What has happened is
E. coli strain A were Hfr cells.
What structure can a bacterium alter to resist the action of sulfa drugs? (see image)
Enzyme
If the bacteria cell plasma membrane was damaged, what step of metabolism would be affected?
Establishment of the hydrogen (H+) ion gradient in the Electron Transport System
You see your lab partner in physics and get a text from them later that night that they have developed the flu. When you get the flu a few days later, your lab partner says you did not catch it from them because in class they were not feeling sick yet. What do you tell your lab partner?
Even if they didn't have signs or symptoms yet, they still could have passed the virus to you during class.
What microbial growth control treatment increases thymine dimers that may inhibit DNA replication and transcription?
Exposure to ultraviolet radiation.
In general, what sorts of pathogens may be able to more successfully attack a patient with an inability to synthesize B cells?
Extracellular (exogenous) antigens
CSF contains high levels of complement and circulating antibodies to prevent infection of the brain and spinal cord.
False
Digestion of microorganisms occurs in phagosomes.
False
The COVID-19 pandemic continues to unfold globally. The Ro value of COVID is high, which is a measure of the fatality rate of the disease.
False
Your immune system does not change from the time you are born until death.
False
T cells are involved in the secondary response only. (T/F)
False T-cells are involved in both primary and secondary responses
Immune cells with CD8 protein expressed on their surface are helper T cells. (T/F)
False cytotoxic T-cells
Secretion of antibodies by activated B cells is a form of cell-mediated immunity. (T/F)
False humoral
Cytotoxic T cells secrete immunoglobulin. (T/F)
False plasma cells
The individual is completely unprotected by the immune system during the lag period. (T/F)
False the innate immune system protects during the lag
Active immunity can be conferred naturally by vaccination. (T/F)
False vaccination is artificial immunity
Vaccination stimulate a secondary immune response. (T/F)
False vaccination stimulates a primary response
Vaccines can be used to treat active/current infections. (T/F)
False vaccines are used to prevent future infections
A bacteria cell is able to perform chemotaxis. Which cell structure is essential for this action?
Flagella
Which of the following statements describes the process of horizontal gene transfer?
Gaining a single new gene sequence from outside of the cell.
A 30-year-old woman was hospitalized after she experienced convulsions. On examination, she was alert and oriented and complained of a fever, headache, and stiff neck. Which of the following is most likely to provide rapid identification of the cause of her symptoms?
Gram stain of cerebrospinal fluid
Herpes simplex virus type 2 (HSV-2) uses epithelial cells in the cervix (part of the female sex organs) as a host cell. HSV-2 does not normally infect epithelial cells in other areas of the body. Which characteristics of HSV-2 explains this tissue tropism?
HSV-2 has spikes that specifically connect/attach to the surface of cervical epithelial cells.
Which of the following is NOT a mechanism of defense against microbial infection in the skin?
Hair follicles prevent entry of microbes into host tissues.
What is unique about the helminths compared to other categories of microorganisms?
Helminths are multicellular at some stages in their life cycle and can be viewed without a microscope.
CD4 cells
Helper T cells
Compare and contrast the activation of helper T cells and cytotoxic T cells (try to use the words MHC I, MHC II, APCs, infected body cell, extracellular, intracellular)
Helper T cells are activated when an EAPC presents an extracellular antigen to them on MHC II. Cytotoxic T cells are activated when an infected body cell presents intracellular antigen to them on MHC I.
The three types of cells that function as donors in conjugation are shown in Figure 8.7. Which can donate chromosomal DNA, in addition to F genes, to a recipient cell?
Hfr AND F'
spontaneous generation
Hypothesis stating that life could arise from nonliving matter; invalidated theory
Which of the following is not a defense of the genitourinary tract?
IgG
Five immunoglobulin classes
IgG (monomer) IgM (pentamer) IgA (secretory dimer) IgE (monomer) IgD (monomer)
Distinguish between innate and adaptive immunity.
Innate immunity is immediate response and puts up a physical barrier, whereas adaptive immunity responses take longer and is antigen-specific
Natural penicillin (penicillin G) is considered a narrow spectrum antimicrobial because
It cannot pass through the porins found in the gram-negative outer membrane
Which of the following statements about Neisseria meningitidis is FALSE?
It is a gram-positive anaerobe.
What makes IgM particularly effective at controlling the spread of an infection in a host?
It is the first type of antibody produced by the adaptive immune system AND Its multiple antigen binding sites enable it to agglutinate many microbes are once.
A pathologist claims it's much easier to determine the causative agent of meningitis than an infection of the skin or intestines. Is this true? Why or why not?
It's true-because the central nervous system (CNS) is generally microbe free, whereas the skin and intestines have a diverse normal flora. Separating out a pathogenic causative agent from the normal microbiota in these areas would be much harder to do than in the central nervous system (CNS).
You are working with two microbe cultures in the lab; one is a bacteria and one is an algae. The labels have fallen off and you need to determine their identity. What information about the cultures could help you distinguish the two tubes?
Knowing that the cells are eukaryotic/prokaryotic.
Although you ate feta cheese contaminated with Listeria monocytogenes, the microbe passed through your body without activating the immune system or making you sick. Why was the L. monocytogenes unable to cause disease?
L. monocytogenes did not attach to host tissues.
ATP synthase
Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP
Blackheads differ from whiteheads because whiteheads are covered by skin, whereas blackheads are open to the air. What causes the dark coloration?
Lipids within the sebum react with air, resulting in chemical oxidation and the formation of the black color.
Consider Griffith's experiments confirming transformation. Which of the following types of Streptococcus pneumoniae will kill mice? (R refers to rough strain, and S refers to smooth strain)
Live R stain mixed with heat-killed S strain
Once inside the phagocyte, how are microbes killed?
Lysozyme and digestive enzymes break apart the microbe in the phagolysosome.
Edward Jenner invented vaccination when he exposed a young boy to cowpox. The boy developed a mild infection and fever. When exposed to smallpox, the boy did not get infected. Which immune cells protected the boy from smallpox?
Memory T and B cells
catabolism
Metabolic pathways that break down molecules, releasing energy.
The steps in Pasteur's experiment with the swan-necked flask are shown in Figure 1 above. In step 4, the flask is tilted to allow broth to enter the neck of the flask. Why does this result in microbe growth in the broth in step 5?
Microbes present in the air settle in the neck of the flask and are brought in contact with the broth when the flask is tilted.
What evidence supports the theory that the eukaryotic cell mitochondria originates from prokaryotic cells that once entered the eukaryotic cell and then stayed there?
Mitochondria have 70S ribosomes, while the rest of the eukaryotic cell has only 80S ribosomes.
If you take an antibiotic that targets the 70S ribosome, what side effects on human cells may occur at high doses of antibiotic?
Mitochondrial ribosomes will be affected.
What can happen if the ciliary defense of the respiratory tract is inhibited?
Mucus and microbes will enter the lungs.
1. Which of the following statements correctly describes the oxidation-reduction reaction in Figure 5.2?
NAD+ is reduced to form NADH, A is oxidized to form B.
NAD in its reduced form is abbreviated as
NADH
electron transport chain formula
NADH + O2 + ADP + PO4 --> NAD + H2O + ATP
Which of the mechanisms below is NOT a protective mechanism of our normal microbiota?
Normal microbiota spread to locations where they are not normally found to prevent colonization by pathogenic microbes.
acellular
Not made up of or containing cells
What is reduced in the following reaction? C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O
O2 is reduced to H2O
hyperthermophiles
Organisms that grow in extremely high temperatures (90 degrees C)
capsid
Outer protein coat of a virus
OIL RIG stands for
Oxidation is loss of electrons Reduction is gain of electrons
The bacterium E. coli is capable of performing aerobic respiration, anaerobic respiration, and fermentation. In what conditions will E. coli use fermentation to generate ATP?
Oxygen is not present in the environment and there is no acceptable inorganic electron acceptor
Each of the following will result in complement activation EXCEPT
PRR binding to PAMP on the microbe.
When phagocytes recognize pathogens, the ___ on the surface of the phagocyte attaches to the ___ on the surface of the pathogen.
PRR, PAMP
To treat an infection with this microbe, which drug would be the best to use base on the MIC data? (see image)
Penicillin
A patient is very ill and needs to be treated immediately with an antibiotic. If the infection is bacterial but the exact bacteria causing it is unknown, which of the following would be the BEST target for your antibiotic?
Peptidoglycan
You work at a small family practice. A man in their early fifties comes in with a complaint of intermittent fever and a minor headache. You are the physician that examines them and the only clinical finding is a wound on their thumb that does not appear infected and which they received while skinning a ground squirrel about three days ago. The patient also has several small bug bites, also not appearing infected, around the wrist of the hand with the wound. The lymph nodes at their neck are swollen but inside their throat looks normal and there are no other visible signs of illness. The patient is up to date on their vaccinations and also received the recommended shingles and influenza vaccines earlier this year. The patient has not been in contact with anyone known to be ill with an infection. A patient sample that you requested is sent to the diagnostic lab and subjected to a Gram stain. Although there appears a Gram-negative bacillus bacteria is present in the sample, results are inconclusive because numbers of bacteria were very low. Based on this, what is your immediate action?
Prescribe an antibiotic immediately and also culture the sample.
Select the statement below that is TRUE for all three types of metabolism (fermentation, aerobic respiration, AND anaerobic respiration).
Process includes glycolysis.
How would you change the Gram negative cell membrane and cell wall shown in Figure 3 to make it look like a Gram positive?
Remove LPS, remove outer membrane, increase the thickness of the wall, and add teichoic acid
aerobic respiration
Respiration that requires oxygen; final electron acceptor is oxygen
Bacillus
Rod shaped bacteria
Leili is a patient is suspected of having impetigo so the sores were swabbed and spread onto a blood agar plate. The image below shows the pattern of microbe growth on the plate with a bacitracin-soaked paper disc added to the surface. S. pyogenes is bacitracin sensitive while S. aureus is bacitracin resistant. Based on the growth pattern, which microbe could be causing the patient's sores?
S. pyogenes
Streptococcus pyogenes causes scarlet fever, sore throat, and skin infections. Why does this violate Koch's postulates?
S. pyogenes removed from a sick organism may cause a different disease when injected into a new host organism.
Your patient has a constant sensation of needing to urinate, feels burning when urinating, and has cloudy urine. You take a urine sample and culture it (allow microbes present in the sample to grow) in the lab. After performing a Gram stain, you conclude that the patient has a urinary tract infection and the causative microbe is the Gram positive bacteria, Staphylococcus saprophyticus. Which of the following statements are TRUE?
S. saprophyticus contains teichoic acid in the cell wall.
Petroff-Hauser chamber
Special slides that facilitate counting because the slide has a grid pattern and the amount of sample delivered to the grid is known
A child presents with large red patches of skin. The top layers are peeling off. Because the parents report that the child hasn't been burned, you suspect that the lesions are due to infection with __________.
Staphylococcus aureus
What evidence supported biogenesis and rejected spontaneous generation in the 1600s?
Sterile broth left at room temperature in a swan-neck flask will not grow microorganisms after several days.
Which of the following statements are TRUE?
Sterilization can be achieved with an autoclave and with dry heat.
What conditions would explain the different death curves for the three strains of aeruginosa in the graph?
Strain B is more resistant to the antimicrobial agent that the wild-type and strain A.
Many groups are working to develop a vaccine for SARS-CoV-2. Novavax is making a vaccine by using only the protein spike on the surface of Sars-CoV-2. What class of vaccines is this one?
Subunit
intracellular antigens
T Cells provide defense against
Compare T cells and B cells
T-cells: cell mediated immunity B-cells: humoral immunity (produces antibodies)
In Griffith's experiment with S. pneumoniae and mice, why did the smooth S strain bacteria kill the mice while the rough R strain bacteria did not?
The S strain cannot be destroyed by the mouse's immune cells AND The S strain is more virulent because it produces a capsule.
Describe how a pathogenic bacterium might be affected by antibodies.
The antibodies may block proteins necessary for the pathogen to bind to the host, may coat the bacterium, or may agglutinate bacteria.
Which of the following is an advantage of the lysogenic cycle for a temperate bacteriophage virus?
The bacteriophage genome is passed on to daughter cells every time the host cell divides.
What is meant when a bacterium is said to become "resistant" to an antimicrobial?
The bacterium is neither killed nor inhibited by the antimicrobial.
Neisseria gonorrhoeae is a Gram-negative coccus bacteria that causes the sexually-transmitted infection gonorrhea. It has a tendency to form biofilms and can horizontally exchange DNA. Based on this information, what can you conclude about Neisseria gonnorrhoeae?
The cell wall of Neisseria gonorrhoeae contains peptidoglycan cross-linked into a strong mesh structure.
lag phase of bacterial growth
The first phase of the bacterial growth curve, in which organisms acclimate to their surrounding; they grow in size but do not increase in number.
A strain of Neisseria gonorrheae has recently acquired the ability to be resistant to the antibiotic penicillin by horizontal gene transfer. After the new genetic information recombines with the genome, how would N. gonorrheae use the DNA?
The gene would be transcribed into RNA and then translated into protein.
How is the completion of the lytic cycle different from staying in the lysogenic cycle with respect to the infected host cell?
The host cell dies during the lytic cycle when newly made viruses lyse the cell.
host range
The limited range of host cells that each type of virus can infect and parasitize.
A bacteriophage infects a host cell and the phage genome integrates itself into the host genome. Sometime later, the prophage DNA is excised from the host cell genome and takes over the host cell machinery. Eventually, mature bacteriophage exit the host cell by lysis. Which process is being described in this scenario?
The lysogenic cycle, reactivating as the lytic cycle
Why does the Center for Disease Control recommend annual screening for chlamydia?
The majority of chlamydia infections are asymptomatic so carriers may transmit to other unknowingly.
When are the chemical and cellular innate immune defenses needed?
The microbe breaches the barriers to infection and gains entry into the host cells and tissues.
Which of the following statements about salmonellosis is FALSE?
The mortality rate is high.
Noncompetitive inhibition
The noncompetitive inhibitor binds to the enzyme and causes the active site to change shape; thus, the substrate is not able to bind to the active site due to enzymatic denaturation.
An inoculated thioglycolate medium culture tube shows dense growth at the surface and sparse growth throughout the rest of the tube. What is your conclusion?
The organisms are facultative anaerobes.
log phase of growth
The second of the four phases of bacterial growth, in which cells divide at an exponential rate.
stationary phase of bacterial growth
The third of the four phases of the bacterial growth curve, in which new cells are produced at the same rate as the old cells die, leaving the number of live cells constant.
Bioremediation
The use of organisms to detoxify and restore polluted and degraded ecosystems.
Describe the penetration step in the virulent phage (lytic) cycle.
The virus overcomes the cell wall barrier and cytoplasmic membrane and injects its genetic material into the bacterial cell wall.
Select the step below that would occur THIRD in the lytic replication cycle of a bacteriophage.
The virus takes over bacterial "machinery" to synthesize viral molecules. The steps involved in this stage can vary in complexity depending on what type of genetic material is housed in the viral capsid.
A viral mutation that causes changes in the glycoprotein spikes would affect which aspect of the virus?
The virus would adsorb to different host cells and its host range would be altered.
Outbreaks of impetigo have occurred at two local preschools. To determine if the two outbreaks are being caused by the same microbe, cotton swabs are used to take a sample of microbes from the blisters of children at each preschool. Samples are subjected to Gram stain and additional tests. Gram stain results indicate that samples from both preschools are Gram positive coccus bacteria. Based on these results alone, why can't you conclude that the microbe causing the two outbreaks is the same?
There are two possible Gram positive microbes that can cause impetigo.
Based on the data in Table 15.1, if the wounds of 100 people were exposed to 10 S. aureus cells without administration of ampicillin, what would be the outcome?
There is a 50% chance the wound will be infected.
Viruses are not included in phylogenetic trees for which of the following reasons?
They are acellular and nonliving.
What is the fate of activated cytotoxic T-cells?
They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells.
plasmolysis
This happens when a cell shrinks inside its cell wall while the cell wall remains intact.
What is the purpose of performing a Gram stain?
To distinguish between a gram positive and gram negative cells, and determine the morphology/shape and arrangement of the bacteria
Which is TRUE of all types of horizontal gene transfer?
Transfer of DNA is between bacteria of the same generation.
Antibodies are produced in greater quantity and faster in the secondary response. (T/F)
True
Each T cell has a T-cell receptor specific to only one antigen and will react to only that antigen. (T/F)
True
In vaccination, a person is exposed to material that is antigen but not pathogenic. (T/F)
True
The adaptive immune system retains a memory of the primary exposure and the response that help in the secondary exposure and response. (T/F)
True
The primary and secondary exposure is to the same antigen. (T/F)
True
Vaccines can be used to prevent severe microbial infections or damage caused by microbial toxins. (T/F)
True
MHC Class II molecules are found on the T cells. (T/F)
True they are also found on EAPCs
Which statement describes the uncoating step of the animal virus cycle?
Viral contents are released in the host cell.
Which of the following is an exception to Koch's postulates?
Viruses require a host cell in order to survive and can't be grown in pure culture in a laboratory.
Compare and contrast the destruction of a pathogen by a helper T cell and a cytotoxic T cell (try to use the words cytokines, phagocytes, and apoptosis)
When the helper T cell binds to antigen presented on MHCII by an EAPC, it will release cytokines to recruit phagocytes to the area to destroy the antigen. When the cytotoxic T cell binds to antigen presented on MHCI by an infected human cell, it will send a signal to the infected cell to undergo apoptosis.
As shown in the lytic cycle in Figure 1, virulent phage are not able to insert DNA into the host cell's genome. However, virulent phage are occasionally capable of carrying out transduction and increasing diversity within a bacterial population. Which of the following is the most likely explanation of how a virulent phage carries out transduction?
When the new phage particles are assembled, a bacterial plasmid is inserted into the phage head.
Which statement correctly explains an error in the phage replication cycle that could lead to transduction?
When the phage is constructed inside the bacteria cell, bacterial DNA is inserted into the capsid.
Antibody
Y-shaped glycoprotein molecule produced by B cells that binds to specific epitopes on an antigen
Refer to Figure 1. If spontaneous generation were TRUE, will microbes grow in the flask pictured in step 2?
Yes
You just returned from a hiking/camping trip and are experiencing symptoms of an infection: high fever, swollen lymph nodes, and black-and-blue marks or hemorrhages under the skin. Your doctor asks if you have been in the four corners area of the U.S. (where the states of Arizona, Colorado, New Mexico, and Utah all meet). What does the doctor suspect?
You might have picked up the plague bacterium from fleas that normally feed on rodents in that area.
Which of the following is an inhibitor that binds to the active site of an enzyme?
a competitive inhibitor
colony-forming units (CFUs)
a counting quantity represented by a colony formed on solid medium from a single cell or a few cells
All viruses and cells share the characteristic of
a genome
memory helper T cells
a long-lived T cell programmed to recognize and quickly mount a secondary response to a specific pathogen upon reexposure
T cell
a lymphocyte that identifies pathogens and distinguishes one pathogen from another
direct microscopic count
a measured volume of a bacterial suspension is placed within a defined area on a microscope slide
antigen/immunogen
a molecule that stimulates an adaptive immune response
temperate phage
a phage that is capable of replicating by either a lytic or lysogenic cycle
Herd Immunity
a reduction in disease prevalence brought about when few individuals in a population are susceptible to an infectious agent
exotoxin
a toxin released by a living bacterial cell into its surroundings, typically living gram-positive cells release these
Antibodies are produced by ________. a. plasma cells b. T cells c. bone marrow d. Macrophages
a. plasma cells
MHC I molecules present a. processed foreign antigens from proteasomes. b. processed self-antigens from phagolysosome. c. antibodies. d. T cell antigens.
a. processed foreign antigens from proteasomes.
Krebs cycle formula
acetyl CoA + 3NAD + FAD + ADP + Pi + 3H2O --> 2Co2 + 3NADH + 3H + FADH2 + ATP + CoA
Oxygen serves as the terminal electron acceptor in
aerobic respiration
genome
all of an organism's genetic material
memory B-cell
an activated and differentiated B cell that is programmed to respond to secondary exposures to a specific antigen
intracellular antigens
an antigen that is inside the host and inside the host's cells
extracellular antigens
an antigen that is inside the host but not inside the host's cells, it remains in the extracellular space
peroxidase
an enzyme that destroys hydrogen peroxide
halophile
an organism that can grow in, or favors environments that have very high salt concentrations
barophile
an organism which can only exist at pressures found at great depths ex: deep sea microbes
A major difference between anaerobic respiration and aerobic respiration is that
anaerobic respiration uses an inorganic molecule as a final electron acceptor while aerobic respiration uses oxygen.
A(n) ________ has multiple ________. ________ can bind to different ________ on the same ________.
antigen, epitopes. Antibodies, epitopes, antigen.
The 1918 Spanish flu virus pandemic was a result of a(n) _____ in which two flu strains recombined to create a very virulent influenza virus.
antigenic shift
The CD8+ T-cell receptor (found on cytotoxic T-cells) binds to
antigens presented on MHC I
Endotoxins
are part of the gram-negative cell wall.
Exotoxins _____.
are secreted by pathogenic organisms
administration of tetanus toxoid is an example of
artificially acquired active immunotherapy
Administration of antibody is an example of
artificially acquired passive immunotherapy
Transformation is the transfer of DNA from a donor to a recipient cell
as naked DNA in solution.
death phase of bacterial growth
as resources become insufficient, bacteria die off
Cellular adaptive immunity is carried out by ________. a. B cells b. T cells c. bone marrow d. neutrophils
b. T cells
extracellular antigens
bacteria, toxins or viruses in bloodstream/fluids
Animals that participate in the life cycles of pathogens and transmit pathogens from host to host are ______.
biological vectors
HIV may be present in
blood, semen, AND vaginal secretions
catalase
breaks down hydrogen peroxide into water and oxygen
1. In Figure 6.1, which line best depicts an obligate anaerobe in the presence of O2?
c
1. Helicobacter pylori can grow in the stomach because it a) hides in macrophages. b) makes a capsule. c) makes urease enzyme that neutralizes HCl. d) makes HCl that raises the stomach pH.
c) makes urease enzyme that neutralizes HCl.
1. Examine the graph in Figure 3 and determine the LD50 of the virus.
cannot be determined from the data collected
viable
capable of living
Which of the following does S. pneumoniae use to survive in the host?
capsules
An interaction between two immune cells and an antigen is shown below. Cell 1 has MHCI on its surface that is bound to an antigen. It is interacting with the T cell receptor on the surface of cell 2. Identify the immune cells.
cell 1: nucleated cell, cell 2: CD8 T cell
In bacterial cells, the electron transport chain is located in the ______.
cell membrane
cluster of differentiation (CD) molecules
cell-surface glycoproteins that serve to identify and distinguish white blood cells
Antigen-presenting cells (APCs)
cells such as B cells, macrophages, and dendritic cells that can present exogenous antigens to naive or memory T cells, activating them
To determine the causative agent of a central nervous system (CNS) infection, a sample is taken from the
cerebrospinal fluid (CSF)
strepto
chains
antimicrobial
chemical compounds that target specific microbial structures and enzymes, killing specific microbes or inhibiting their growth. may be naturally produced, semisynthetic, or synthetic
"Rice water stools" are characteristic of
cholera.
superantigen
class of exotoxin that triggers a strong nonspecific immune response with excessive production of cytokines (cytokine storm) causing inflammation, high fever, shock, and, potentially, death
turbidity
cloudiness of water
staphylo
clusters
Psychrophiles
cold-loving microbes
Vibrio
comma shaped bacteria
The lower respiratory tract is protected by all of the following EXCEPT
competition with the normal flora of the lungs.
biofilm
complex ecosystem of bacteria embedded in a matrix
How could disease transmission be stopped at the portal of exit?
covering the mouth when sneezing AND wearing a condom.
An individual contracted the Zika virus, which entered the host's cells where it will replicate itself. What type of immune cell in the host will recognize Zika antigens?
cytotoxic T cells
A single antigen molecule may be composed of many individual ________. a. T-cell receptors b. B-cell receptors c. MHC II d. epitopes
d. epitopes
Sytox green is a dye that lights up when bacteria cells die. You mix a two day-old bacteria culture with Sytox green and it glows brightly green. What is the most likely growth phase of the culture?
death
Table 15.1 shows the Infectious Dose (ID50) for Staphylococcus aureus in wounds with and without the administration of ampicillin before surgery. Based on the data, the administration of ampicillin before surgery
decreases the risk of staphylococcal infection.
In order to establish biofilms within the intestines of humans, bacteria may adhere initially to the intestinal wall using fimbrae before secreting the EPS protective matrix that protects the bacteria from
dehydration AND antimicrobial drugs
One disadvantage to using broad-spectrum antimicrobial is that they
destroy normal microbiota
Minimum Inhibitory Concentration (MIC) test
determines the lowest antibiotic drug concentration that inhibits visible bacterial growth, Etest
In comparing the bacteria shown in Figure 11.1 the genotypes of B. cereus and B. anthracis are _____, which would lead to their phenotypes being ____.
different, different
Which of the following is a disadvantage of measuring bacterial growth with a Petroff-Hauser direct microscope count?
difficult to distinguish live from dead bacteria AND can't measure motile bacteria
Which of the following is a disadvantage of measuring bacterial growth with a direct microscope count shown in Figure 3?
difficult to distinguish live from dead bacteria AND can't measure motile bacteria
cytotoxic T cells or "killer T cells"
effector cells of cellular immunity that target and eliminate cells infected with intracellular pathogens through induction of apoptosis
Antibody-dependent cell-mediated cytotoxicity (ADCC)
enables NK cells to kill pathogens
If the endemic level of pertussis is approximately 3,500 cases per continent, how would you categorize the occurrence of pertussis in 2015?
endemic
What is NOT present in ALL animal viruses?
envelope
superoxide dismutase
enzyme that catalyzes the breakdown of superoxide anions
The outbreak of cholera in 1854 was isolated to the London area, where cholera does not normally occur. This pattern of cholera incidence can be categorized as a(n)
epidemic outbreak
Which term refers to the study of the cause of disease?
etiology
The toxin that causes a separation in the layers of skin and a breakdown in the tissue structure that can be used in diagnosis of staphylococcal infections is ______.
exfoliative toxin
MHC II
exogenous antigen-presenting cells (EAPCs) express MHC II
Vibrio cholera produces cholera toxin, an ______ that causes host cells to _____.
exotoxin, secrete fluids and electrolytes
You plate a bacteria culture on an agar plate containing all essential nutrients. When you remove it from the incubator the following day, you can tell that the number of bacteria have greatly increased because there is visual growth and all of the carbohydrate added to the agar has been metabolized (which led to a visible color change in the agar). The bacteria culture is most likely to be in which phase of the growth curve?
exponential phase
Antigens that come from ____ pathogens and are presented on MHC___ by ____ cells will activate _____T cells.
extracellular, II, antigen-presenting, helper OR intracellular, I, infected body, cytotoxic
An organism that can exist in both oxygen and oxygen-free environments is a(n) ______.
facultative anaerobe
Cultures of a bacterial strain were incubated in a standard incubator and in an anaerobic jar. After incubation, there was moderate growth of cultures in the anaerobic jar, but heavy growth of the culture in the incubator. This species is a(n) ______.
facultative anaerobe
The data in Table 6.2 showing growth with and without salt (NaCl) indicate that S. aureus is a(n)
facultative halophile
Autoimmune disorders are characterized by immune destruction of self-tissues. The underlying basis of these disorders is
failure to delete B and T cells that are reactive to self.
The cardiovascular system is highly protected from microbial infection because
failure to do so will result in a systemic infection.
A bacterial cell has replicated its plasmid, and when this cell divides into 2 daughter cells, each cell receives one copy of the plasmid. This is an example of horizontal gene transfer.
false
After binary fission, daughter cells will differ genetically.
false
All bacterial cells can form endospores. (T/F)
false
All contacts with a pathogen will result in infection.
false
All viruses destroy their host during release. (T/F)
false
Antibiotics cause bacteria to mutate their DNA in order to become drug resistant.
false
Koch's postulates are easily satisfied for viral diseases.
false
The infectious dose of most pathogens is about equal.
false
You are studying Griffith's experiment. You inject mice with dead Smooth strain S. pneumoniae bacteria. Your lab partner predicts the mice will die. Your partner is correct.
false
Which of the following would be considered a sign of a disease?
fever of 39 degrees celsius
The primary virulence factor of Neisseria gonorrhoeae is ______.
fimbriae
Sporulation
formation of endospores
How would you classify a virus?
generally smaller in size than a bacterial cell; nonliving
Which one of the following does NOT contribute to the incidence of nosocomial infections?
gram-negative cell walls
growth curve (see image)
graph of the number of organisms in growing population over time
You add the two bacteria shown in Figure 11.1 to the same tube with liquid growth media. After a 24 hour incubation with shaking, you are able to identify B. cereus cells that contain the pX01 and pX02 plasmids. Which explains how B. cereus most likely acquired pX01 and pX02?
horizontal gene transfer
extracellular polymeric substance (EPS)
hydrated gel secreted by bacteria in a biofilm containing polysaccharides, proteins, nucleic acids, and some lipids
artificial active immunity
immunity acquired from medical intervention and individual receives an immune stimulus
artificial passive immunity
immunity acquired from medical intervention and individual receives antibodies (antitoxin)
natural active immunity
immunity acquired from normal experience and individual receives an immune stimulus
natural passive immunity
immunity acquired from normal experience and individual receives antibodies (antitoxin)
Antibody
immunoglobulin proteins made by B cells, made in response to a specific antigen, involved in body's defense against pathogens or toxins in the extracellular environment
What is true for all types of metabolism?
includes glycolysis
In the progression of a S. pyogenes (Strep throat) infection, signs/symptoms occur rapidly after exposure because of a short ____ period.
incubation
Adhesins are
involved in the first step of the infectious process AND specific to the pathogen's portal of entry.
Agglutination
involves antibodies binding to epitopes on two or more bacteria simultaneously
Opsonization
involves antibodies tagging pathogens for destruction by phagocytosis
neutralization
involves binding of antibodies to antigens to prevent them from attaching to target cells
Biological transmission differs from mechanical transmission in that biological transmission
involves reproduction of a pathogen in an insect vector prior to transmission.
Which of the following is NOT true of conjugation?
involves the action of bacteriophage
Which enzyme is responsible for joining DNA fragments to make a continuous new DNA strand during DNA replication?
ligase
endotoxin
lipid A component of lipopolysaccharides in the outer membrane of gram-negative bacteria, released when gram-negative cell lyses
What is the toxic component of endotoxin?
lipopolysaccharide (LPS)
Mary Mallon worked as a cook in New York in the early 20th century. Over seven years, from 1900 to 1907, Mallon worked for a number of different households unknowingly spreading typhoid fever, a bacterial infection caused by Salmonella enterica with mild to severe symptoms, in the area. Mary Mallon is a(n) ____ of S. eneterica.
living reservoir AND asymptomatic carrier
Biogenesis
living things originate form other living things only
Penicillin would have the most effect on bacteria in which phase of the growth curve? (see image)
log
Phagocytes utilize all of the following to help locate and contain microorganisms EXCEPT
lysozyme.
Virulent phages undergo a(n) ____ life cycle, whereas temperate phages are capable of undergoing a(n) ____ cycle.
lytic, lysogenic
Exogenous antigens bound to MHCII on the surface of a B cell...
made it past the innate immune system defenses.
Helicobacter pylori can grow in the stomach because it
makes urease enzyme that neutralizes HCl.
Bacterial encephalitis and meningitis are difficult to treat because
many antibiotics cannot penetrate the blood-brain barrier.
thioglycolate medium
medium designed to test the aerotolerance of bacteria; it contains a low concentration of agar to allow motile bacteria to move throughout the medium
The membranes that cover the surface of the brain and spinal cord are known as the
meninges
Use Figure 6.4 to categorize the bacterium Listeria monocytogenes, which has an optimum growth temperature between 30-37°C and can grow in temperatures as low as 15⁰C.
mesophile
anaerobic respiration formula
metabolic process that occurs in the absence of oxygen; final electron acceptors are inorganic compounds (i.e., sulfates and nitrates)
Outside of living cells, viruses are
metabolically inactive
viable plate count
method used to determine the number of living bacteria present in a sample
MHC I
molecules found on every body cell that presents antigen; signals cytotoxic T to destroy
MHC II
molecules found on macrophages, B cells, and activated T cells; signal helper T cells
T-cell receptors (TCR)
molecules on T cells involved in the recognition of processed foreign epitopes presented with MHC I or MHC II
electron carriers
molecules that can carry high energy electrons through the electron transport chain; NADH and FADH2
Virulent pathogens are
more likely to cause severe disease
Bacteria can acquire genetic diversity by
mutation AND horizontal gene transfer
Production of IgE in response to pollen is an example of
naturally acquired active immunotherapy
acquisition of maternal antibodies in breast milk is an example of
naturally acquired passive immunotherapy
Central tolerance
negative selection of self-reactive T cells in thymus
central tolerance
negative selection of self-reactive T cells in thymus
Refer to Figure 6.7. Based on growth, this bacteria is a(n)
neutrophile
progeny virus
newly assembled viruses
Disease transmitted by droplet contact will most likely enter the human host through what portal of entry?
nose
Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a
nosocomial infection
Halobacterium salinarum lives in and requires a high salt concentration. This is an example of an archaeon described as a(n) ______.
obligate halophile
A molecule is __________ when an electron is removed.
oxidized
Antigen
pathogen-specific molecular structure that triggers an adaptive immune response, antibody generators, microbial or nonmicrobial, specific region recognized by antibody is called an epitope
The difference between the terms pathogenicity and virulence is that
pathogens cause disease and their virulence describes the degree of pathogenicity
Which of the following is not an example of an enzyme used to detoxify reactive oxygen species?
permeases
A child falls and suffers a deep cut on her leg. The cut went through her skin and she is bleeding. Which of the following defense mechanisms will try to eliminate contaminating microbes immediately?
phagocytosis and the inflammatory resonse
The digestive tract is essentially one long tube. The order of the structures, beginning with the mouth, is
pharynx, esophagus, stomach, small intestine, large intestine.
During the lag phase, bacteria cells are
preparing for cell division
If an incubation period exists for a certain disease, it should occur prior to
prodromal
Glycolysis
produces ATP AND may occur under aerobic or anaerobic conditions
apoptosis
programmed cell death
immunoglobulin
protein with antibody activity
Viral spikes
protrude from the viral envelope; attach specifically to host cell receptors
Refer to Figure 1. Cultures of a bacterial strain were incubated in a refrigerator (5°C), on a lab bench (18°C), in a 37°C incubator, and in a 50°C incubator. After incubation, there was no growth at 37°C and 50°C, slight growth on the lab bench, and abundant growth on the refrigerator. Which term best describes this organism?
psychrophile
The circulating substances that affect the hypothalamus and initiate fever are ______.
pyrogens
Which list of three terms best describes innate immunity?
quick, nonspecific, and unchanged from birth
A molecule is __________ when it gains an electron.
reduced
Vibrio cholera produces cholera toxin that causes release of ions into the intestinal lumen and leads to
release of water into the lumen as well AND rice water stools.
The DNA pictured in Figure 8.1 is going through what essential process?
replication
The body region where a ciliary escalator helps to sweep microbes trapped in mucus away from that body site is the ______.
respiratory tract
You need to measure microbial growth in a culture of motile bacteria. The concentration of the culture is very low, you need to determine the number of live bacteria cells, and you have plenty of time. Which method would be the best to use?
serial dilutions and viable plate count
The objective, measurable evidence of disease evaluated by an observer is termed a/an ______.
sign
Epitope
smaller exposed region on an antigen that is recognized by B-cell and T-cell receptors and antibodies
Cocci
spherical shaped bacteria
Spirillum
spiral shaped bacteria
The phase of the bacterial growth curve in which the rate of multiplication equals the rate of cell death is the ______.
stationary phase
catalyst
substance that speeds up the rate of a chemical reaction
Enzymes act on _______ to generate ________.
substrates, products
A characteristic symptom of plague is
swollen lymph nodes.
memory
the ability of the specific adaptive immune system to quickly respond to pathogens to which it has previously been exposed
specificity
the ability of the specific adaptive immune system to target specific pathogens or toxins
fermentation (anaerobic respiration)
the breakdown of sugars without the use of oxygen, regenerate NAD+ so glycolysis can continue; reduction of pyruvate; final electron acceptors are organic compounds (i.e., alcohols, CO2, lactic acid, acetic acid, vitamins, antibiotics, and hormones)
metabolism
the chemical processes that occur within a living organism in order to maintain life.
The most common route of central nervous system invasion by pathogens is through
the circulatory system.
The fundamental difference between an organism's genotype and its phenotype is that
the genotype refers to all of the genetic material in the organism, whereas the phenotype represents only the genetic material that is expressed into proteins.
The bacterial chromosome is located in
the nucleoid region
Opportunistic infectious agents arise from microbes that are ______.
the patient's own normal biota
tissue tropism
the range of tissue types that a virus can infect
Human-to-human transmission of plague is usually by
the respiratory route.
chemiosmosis
the use of energy in a H+ gradient to drive cellular work; H+ passively flows through the ATP synthase which leads to the creation of ATP.
A sample of coli has been subjected to heat for 17 minutes and all of the cells in the sample are destroyed. Which of the following terms best describes this event?
thermal death time
mesophiles
those growing best between 20 degrees and 40 degrees celcius; the human pathogens are in this group
generation/doubling time
time required for a complete fission cycle from parent cell to two new daughter cells
Kirby-Bauer disk diffusion test
to determine the susceptibility to specific microbes to various antimicrobial drugs
You isolate a bacterium that can transfer genes to other bacteria without being in direct contact with them. You isolate the medium in which this bacteria is growing (being very careful not to leave any of the bacteria in the medium), and treat it with protease, then add new bacteria and allow them to grow in this medium. You find these bacteria have NOT acquired new genes. The genes are most likely transferring by
transduction
The function of the "ciliary escalator" is to
trap microorganisms in mucus and move them away from the lower respiratory tract.
A student has obtained a sample of pond water for study. Using a high-powered microscope lens, she observes several cells with nuclei. She can conclude that the cells are NOT bacteria.
true
An asymptomatic, healthy carrier of a disease is a living reservoir of infection.
true
Humans can be reservoirs for pathogens.
true
In hospital patients, normal microbiota can become opportunistic pathogens that lead to Healthcare-Associated Infections.
true
In treating genitourinary disease with discharge as a sign, it is important to consider that N. gonorrhoeae and C. trachomatis are often both present and must both be treated.
true
The degree of turbidity in a broth culture correlates to the amount of cell growth.
true
The prevalence of HIV is generally higher than its incidence.
true
The production of ATP via the electron transport system, in either eukaryotes or prokaryotes, requires the use of a membrane. (T/F)
true
Transcription occurs within the nucleus or at the nucleoid.
true
Viral meningitis is much more common than bacterial meningitis.
true
spectrophotometer measures
turbidity
A molecule of DNA is constructed of
two strands of nucleotides wound into a double helical shape.
T cells and B cells
two types of lymphocytes
reactive oxygen species (ROS)
unstable and toxic ions and molecules derived from partial reduction of oxygen
Urine leaves the urinary bladder through which structure?
urethra
During a six-month period, 239 cases of pneumonia occurred in a town of 300 people as a result of Coxiella burnettii infections. Before the outbreak, 2000 sheep were kept 30 miles northwest of the town, 95% of sheep tested were positive for C. burnetii. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years. The method of transmission of the disease in Situation 14.1 was
vehicle
In 1854 a cholera outbreak in London was caused by contamination of drinking water with the bacteria Vibrio cholerae and killed over 10,000 people. This is an example of disease transmission by
vehicle
Genes can be shared between organisms by horizontal or vertical gene transfer. Humans are capable of _______ gene transfer and bacteria are capable of ________ gene transfer.
vertical, both horizontal and vertical
What is NOT a product of the Krebs cycle?
water and glucose
allosteric site
where a noncompetitive inhibitor binds to an enzyme
active site
where a substrate binds to an enzyme
The Ro of Covid-19 is higher than other coronaviruses like MERS and SARS. This means that in comparison to MERS and SARS, Covid-19
will spread more quickly.