Exam 3 Flashcards
Why must the genome of HPV enter the nucleus for replication?
The DNA genome of HPV can only be replicated in the nucleus where host DNA polymerase is found
Blocking which enzyme/process would have little to no effect on influenza? Translation, neuraminidase, DNA polymerase, RNA polymerase
DNA Polymerase
One way that viruses are useful to humans is their function as
Cloning Vectors
Which groups package their own RNA dependent RNA polymerase?
Group 5 (negative sense RNA)
Group 3 (double stranded RNA)
What is the cure for infection with HIV?
No cure
Which is false about influenza?
- Genome maximizes gene reassortment
- Genome is well designed for evasion of immune system
- Genome is tiny to allow for generation of as many virions as possible
- Genome allows for large quantities of virions to be created
Genome is tiny to allow for generation of as many virions as possible
Which is not a possible effect or viral replication in host cell?
- Death
- Differentiation
- Alteration of genome
- Debilitation
Differentiation
What type of vaccine is the live, weakened measles virus?
Attenuated whole-agent
In contrast to natural infection, an effective commercial vaccine should not harm the person being vaccinated. It should do all except
- Cause passive immunization
- Produce long-term memory
- Stimulate T-cell responses
- Stimulate B-cell responses
Cause passive immunization
Segmented influenza RNA genomes are capable of
- cell fusion
- reassortment
- reverse transcription
- proviral transposition
Reassortment
An enveloped virus obtains its envelope from
The host cell (membrane)
A big reason as to why the HIV virus thus far cannot be cured is that is
- contains a viral envelope
- contains a protease
- contains integrase
- is a retrovirus
Contains integrase
West Nile virus is capable of infecting many different organisms (humans, birds, raccoons). This information indicates that West Nile virus has
A broad host range
A plasmid-encoding protein antigen from West Nile virus is injected into muscle cells. This is an example of a(n)
DNA vaccine
A virus might have evolved to cause cancer in a host cell to
Produce more cells for the virus to infect
What type of bacteriophage infection results in immediate death of the host cell?
Lytic
Which process is used to remove pathogens from health care workers
Antisepsis
Which process is used to remove pathogens from hospital beds
Disinfection
All of the following are molecules that can be selectively targeted by antibiotics except
- 50S Ribosomal subunit
- Peptidoglycan
- 30S Ribosomal subunit
- DNA
DNA
Which antibiotic resistance mechanism is exemplified by beta-lactamase?
Destroy the antibiotic before it gets into the cell
Drug A 17 g/kg toxic dose, 8 g/kg therapeutic dose
Drug B 6 g/kg toxic dose, 4 g/kg therapeutic dose
Which is safer?
Drug A
Acidophile would live in, alkaliphile would live in
Stomach, Duodenum
What can completely change the intestinal mix of microbes
Antibiotic treatments
What is capable of passing through placental membrane and endothelial cells to infect developing fetus?
Listeria monocytogenes
Which situation does not demonstrate importance of healthy microbiome?
- Eating yogurt and taking probiotics
- Microbes break down lactose for lactose intolerants
- During colon cancer, opportunistic bacteria infection occurs
- Antibiotics to treat MRSA causes diarrhea
Opportunistic
What is an optimal pH for Helicobacter pylori, in human stomach
pH 5
Presence of what in the bacterial cell wall is one of the mechanisms of antibiotic selective toxicity?
Peptidogylcan
Inhibition of viral envelope acidification would ___ an influenza infection?
Inhibit
The function of polymyxin is similar to that of a detergent. What cell structure will be most affected by this drug?
Cell membrane
Individuals take probiotics to
Restore balance to the microbial community
Why do the residents of our normal microbiota not regularly invade other tissues of the body?
They have not evolved the ability
The presence of ___ is essential for preventing respiratory infections.
Mucociliary escalator
Which of the following is NTO a specific function carried out by microbes in the intestine?
- Promotion of tissue development
- Contribution to digestion
- Immune system stimulation
- Glucose regulation
Glucose regulation
The Baltimore model of classification is based on classifying genetic information as
- coding v noncoding
- RNA v DNA
- Single v double stranded
- all of these
all of these
What group is most negatively affected by antiviral reverse transcriptase inhibitors?
Group VI
The use of overlapping reading frames in viruses leads to
A shorter genome
All are used in vaccines except
- inactivated viruses
- antibodies
- toxoids
- parts of bacterial cells
Antibodies
What is false? An effective vaccine should
- protect against natural pathogen
- not require many boosters
- deactivate B cells and T cells
- generate memory
Deactivate B cells and T cells
How is HPV able to keep its genome so small
Overlapping genes
Which antibiotic inhibits the formation of the peptide side chain of NAM?
bacitracin
vancomycin
cycloserine
cephalexin
cycloserine
Lipopolysaccharides, flagellin, and double-stranded DNA are microbe-associated molecular patterns recognized by
pattern recognition receptors.
ribosomes.
tight junctions.
tumor necrosis factors.
pattern recognition receptors
Examine the figure below. Which Toll-like receptor is activated specifically by Gram-positive organisms?
Teichoic Acid Receptor
Viruses cause more illnesses on an everyday basis than do bacteria. Why are there so few antiviral agents compared to antibacterial agents?
Viruses use functions of the host to replicate themselves, so achieving selective toxicity is difficult.
What is NOT a reason the skin is hard to colonize?
low water activity
drying out
high pH
high amounts of salt
high pH
Which microbial reservoir has the largest anaerobe-to-aerobe ratio?
mouth
skin
genitourinary tract
intestine
intestine
How do TLR interact with MAMS, microbial associated molecular pathogens?
They trigger immune signaling pathogens
Both HPV and HIV can remain in a latent state for months to years. In this case, the term “clinical latency” refers to
a. the period of time between the initial entry of the virus into the host cell and the appearance of the first symptoms.
b. the period of time when the virus is detectable in the host until the disease has run its course.
C. a period of time after the initial infection when the virus is not causing symptoms and is virtually undetectable.
d. the period of time between the initial infection and the integration of the virus genome into the host’s genome.
C. a period of time after the initial infection when the virus is not causing symptoms and is virtually undetectable.
Which of the following is NOT a reason why antiviral agents are hard to develop?
a.Because virus genomes are so small, there are relatively few molecules that can be used as drug targets.
b.Antiviral agents usually have severe side effects because viral replication involves many host cell processes.
C. To destroy the virus, the host cell must also be destroyed.
d.Drug-resistant strains develop rapidly because viruses mutate quickly within the host.
C. To destroy the virus, the host cell must also be destroyed.
C. To destroy the virus, the host cell must also be destroyed.
Which of the following viruses is dependent upon an RNA-dependent
RNA polymerase for replication?
a. human papillomavirus, a dsDNA virus
b. HIV, a retrovirus
c. T4, a dsDNA bacteriophage
d. influenza, an ssRNA virus
d. influenza, an ssRNA virus
Hypothesize which characteristic of the influenza virus makes the genome particularly susceptible to antigenic shift.
a. The genome is comprised of RNA, not DNA.
b. The capsid is coated with a host-derived envelope.
c. The genome is segmented.
d. The genome is (-) sense.
c. The genome is segmented.
A benefit of vaccination is that a child will
a. generate antibodies to a pathogen without getting sick.
b. develop antibodies through natural immunity.
c. develop more infections than necessary.
d. protect other children who cannot be vaccinated.
e. both A and D
e. Both a and d
Complete destruction of all microorganisms on a surface can be achieved by
а. antisepsis.
b. disinfection.
C. sterilization.
d. sanitization.
C. sterilization.
Hypothesize why there are more chemotherapeutic agents that block bacterial protein synthesis than chemotherapeutic agents that block viral protein synthesis.
a. Viral protein synthesis occurs inside of the host cell, while bacterial protein synthesis does not.
b. Viral protein synthesis relies entirely on host ribosomes.
C. Bacterial protein synthesis relies entirely on host ribosomes.
d. Viral protein synthesis does not involve ribosomes.
b. Viral protein synthesis relies entirely on host ribosomes.
Which of the following is target for an antiviral drug?
a. cell wall synthesis b.
protein synthesis by ribosomes
c. an enzyme in a biochemical pathway
d. DNA or RNA synthesis
d. DNA or RNA synthesis
Hypothesize which characteristic of the influenza virus makes the genome particularly susceptible to antigenic shift.
a. The genome is comprised of RNA, not DNA
b. The capsid is coated with a host-derived envelope.
c. The genome is segmented.
d. The genome is (-) sense.
c. The genome is segmented.
Which area of the human body is NOT likely to be a site of colonization with microbiota bacteria?
a. skin
b. mouth
c. brain
d. intestine
c. brain
A bacterial species that can survive in the stomach is likely able to tolerate _____
conditions.
a. alkaline
b. basic
c. dry
d. acidic
d. acidic
Why might methanogenic archaea influence weight gain?
a. Methanogens produce H2, which promotes fermentation.
b. Methanogens produce H2, which slows fermentation.
C. Methanogens use H2, which promotes fermentation.
D. Methanogens use H2.which slows fermentation.
C. Methanogens use H, which promotes fermentation.
Which of the following would be able to cross the blood-brain barrier under normal circumstances?
a. bacterial cells
b. glucose molecules
c. toxin proteins
d. protozoa
b. glucose molecules
What is a common mechanism by which bacteria develop antibiotic resistance?
Mutation in the target site of the antibiotic
Which is a characteristic of the flu virus replication cycle?
- Integration into the host DNA
- Use of host cell machinery for replication
- Independent replication outside the host cell
- Production of chlorophyll
Use of host cell machinery for replication
A noninfectious disease that can be linked to changes in the microbiota is
Norovirus gastroenteritis
Irritable bowel syndrome
Food poisoning
C difficile infection
Irritable bowel syndrome
The successful cotreatment of septic Enterococcus infections with vancomycin and an aminoglycoside is an example of antibiotic
Antagonism
Resistance
Sensitivity
Synergism
Synergism
