Chapter 1
Which of the following is NOT a microbial role?
a) Producing vitaminsb) Nitrogen fixation
c)Competition against eukaryotes
d) Serving as primary producers
c) Competition against eukaryotes
___ is likely to cause disease after infection in a healthy host while ____ is likely to cause disease in immunocompromised patients.
primary pathogens (moderate to high virulence)
opportunistic pathogens (low virulence)
What light interaction is most prominent in how darkfield microscopy works?
a) Absorption
b) Reflectionc) Refraction
d) Scattering
Scattering
Which of the following is NOT paired correctly?
a) Prokaryotes, no histones
b) Eukaryotes, no cell wall
c) Prokaryotes, divides by binary fission
d) Prokaryotes, circular or linear chromosome
b) Eukaryotes, no cell wall
Not true --> they just have polysaccharide cell walls when they are present.
Who is the scientist credited for vaccination? He found that cowpox could be used as a vaccine for smallpox
Jenner
What is NOT true about archaea?
a) they have a nucleus
b) they are prokaryotic
c) they can live in extreme conditions
d) they are generally not thought of as pathogenic
a) they have a true nucleus
--> archaea have no true nucleus
___ occurs when a pathogen or parasite enters and begins to grow on the host
a) Disease
b) Infection
answer is infection (most infections don't cause symptoms or can go unnoticed)
disease is when the patient actually develops symptoms
A student is preparing to do gram-staining. As they do the steps, the student accidentally skips the safranin at the end. What color is the bacteria? (Hint: bacteria is e.coli)
clear
Are targeting ribosomes for antibiotics selectively toxic or no? Explain
Yes because Eukaryotes have 80S while Prokaryotes have 70S which makes it pretty selectively toxic. However, peptidoglycan is still the best option.
____ is when signs and symptoms of disease is caused by the host's response to the infection
Immunopathology
Louis Pasteur is famous for disapproving ____ through his famous swan-neck experiment.
This ended up proving ____.
He disapproved spontaneous generation and proved biogenesis.
In the process of colonization, the _____ on bacteria help them attach to receptors on host cells.
adhesins
a) Bacillus does not form endospores
b) The water was left on for too long.c) The bacteria is vegetative
d) No way to know
c) the bacteria is vegetative meaning it was in a good environment, so it did not form endospores under the good conditions. Therefore, the malachite green did not respond
What am I explaining:
In gram-postive bacterial cell walls.
Provides flexibility to the cell wall.
Teichoic acid
A student got a papercut and the infection spreads through the bloodstream to another area of the body. What type of infection is this?
A) Latent infection
B) Focal infection
C) Acute infection
D) Chronic infection
b) focal infection
What are the limitations of Koch's postulates?
Some diseases do not always cause disease for the host / asymptomatic patients
Some pathogens only have humans as host
What is the difference between virulence and pathogenicity?
Virulence is the level of harm caused by a pathogen FOLLOWING INFECTION (severity). Meanwhile, Pathogenicity is the ability of the organism to CAUSE DISEASE.
What is the path of light through a compound microscope?
a) Light source --> diaphragm --> Specimen --> Condensor --> ocular lens --> objective lens --> eyes
b) Light source --> condensor --> diaphragm --> objective lens --> ocular lens --> specimen --> eyes
c) Light source --> diaphragm --> condenser --> specimen --> objective lens --> ocular lens --> eye
c)
LPS is on ____ membrane of ____ bacteria. LPS consists of something called the Lipid A which acts as a ____
LPS is found on the outermembrane of gram-negative bacteria.
Lipid A acts as an endotoxin
What is immersion oil used for?
Under 100x or high magnification, the immersion oil prevents light from refracting so that it can enter the objective lens.
Who is the scientist that discovered penicillin on accident and discovered the first antibiotic?
Alexander Fleming
Agent A has an LD50 of 300 while Agent B has an LD50 of 200. What is considered more infectious?
A) Agent A
B) Agent BC) cannot determine from the data
C) Cannot determine from this data
Because this would be ID50 for infection. LD50 is for mortality / danger
A scientist wants to observe the internal structures of the bacteria, specifically the ribosome. They want to observe in extremely high resolution and magnification. What should the scientist use?
A) SEM
B) TEM
C) Compound microscope
D) Fluorescence microscope
B) TEM
A bacteria that uses flagellar motility senses an attractant through _____.
They want to run towards the attractant, so they do a ____ rotation
chemotaxis
Counterclockwise rotation to run --> clockwise is tumble
Which of the following is NOT present in bacteria
a) capsuleb) pilli
c) glycocalyx
d) cilia
d) cilia