MicroBio 303 Exam Questions and
answers graded A+
Gram-negative bacteria can release endotoxins but Gram-positives cannot, because -
ANS✅✅Gram-negative bacteria have lipopolysaccharides in their outer membrane
A major difference between the hydrogen and covalent bonds found within the DNA double helix is
that: - ANS✅✅Hydrogen bonds are formed between the base pairs, whereas covalent bonds are
formed between the phosphate and sugar groups, and neither provide the primary stabilization
factor for the helix.
DNA structure is characterized by all of the following EXCEPT: - ANS✅✅High rigidity
(I said long length)
Based on size what is the correct order of the following? (Smallest on the left to largest on the right)
- ANS✅✅Ribosome < Average Virus < Average Prokaryote < Average Eukaryote
Which of the following is NOT true when regarding chemo taxis? - ANS✅✅It is a directed non-
random movement toward an attractant or away from a repellent
You discovered a strange microorganism. You want to first examine the motile microorganism in its
natural state and then to determine the structure of the protein that forms the pili. What kinds of
microscopes you should use? - ANS✅✅Phase Contrast Microscope and X-Ray Crystallography
(I said light instead of Phase)
Your roommate is sick with the flu and is bashing microbes due to the fact that they caused her
sickness. Which of the following is not a fact to use to convince her that microbes are more good
than bad? - ANS✅✅Microbes produce toxins to fight against cell degradation
(I said Microbes are one of the body's first lines of defense against illness and injury)
If DNA is used to store information for many organisms, what statement is INCORRECT about the
RNA used by retroviruses to store their genomes? - ANS✅✅The retrovirus has an integrase that is
used to integrate its RNA into the genome of the cell
( I said The retrovirus has a 5' cap on the RNA because they only infect eukaryotes.. also have tail)
, Microbes have many impacts on the environments and on humans themselves, which of the
following is false? - ANS✅✅Most microbes cause disease i.e small pox
Which of the following is FALSE when referring to the Peptidoglycan of a bacterium? - ANS✅✅Its
tightly wound mesh-like structure results in a highly selective barrier
(I said Its structure is held together by crosslinking peptides)
Why was there a large amount of time between when Thonis Philipszoon discovered microbes and
when we began to cultivate and understand them? - ANS✅✅No suitable methods had yet been
developed that permitted cultivation of large populations.
( I said effective visualizing instruments were not available)
If Thonis Philipszoon had discovered microbes during the industrial revolution, would the cultivation
and understanding of microbes have began sooner? - ANS✅✅Indeterminable; while the resources
would be available, we would not know if the inclination to study microbes would take time to
develop or result immediately after Thonis' discovery.
Microorganisms are important for our health because - ANS✅✅bacterial infections cause about
25% of deaths worldwide
A rod-shaped cell has a mutation such that when the temperature is raised above 37°C, it can no
long produce FtsZ. If you grew these cells at 40°C and then observed them via a Gram stain. You
would see - ANS✅✅Filaments (longer rods than normal)
(I said Small coccus-shaped (spherical) cells)
With a living microbe that may be transparent, which type of microscope will provide a higher
quality image without staining or killing the specimen? - ANS✅✅Phase-Contrast Microscope
( I said Fluorescent)
Who discovered the reason for wine souring and why was this discovery significant? -
ANS✅✅Pasteur; it proved that microbes cause infection
( I said Pasteur; it proved wine was souring due to a chemical reaction)
All of the following are true statements about the bacterial membranes except - ANS✅✅A
membrane with lots of unsaturated fatty acids will be less permeabe
( I said The outer membrane has porins that allow ions like Na+ to easily pass through)
answers graded A+
Gram-negative bacteria can release endotoxins but Gram-positives cannot, because -
ANS✅✅Gram-negative bacteria have lipopolysaccharides in their outer membrane
A major difference between the hydrogen and covalent bonds found within the DNA double helix is
that: - ANS✅✅Hydrogen bonds are formed between the base pairs, whereas covalent bonds are
formed between the phosphate and sugar groups, and neither provide the primary stabilization
factor for the helix.
DNA structure is characterized by all of the following EXCEPT: - ANS✅✅High rigidity
(I said long length)
Based on size what is the correct order of the following? (Smallest on the left to largest on the right)
- ANS✅✅Ribosome < Average Virus < Average Prokaryote < Average Eukaryote
Which of the following is NOT true when regarding chemo taxis? - ANS✅✅It is a directed non-
random movement toward an attractant or away from a repellent
You discovered a strange microorganism. You want to first examine the motile microorganism in its
natural state and then to determine the structure of the protein that forms the pili. What kinds of
microscopes you should use? - ANS✅✅Phase Contrast Microscope and X-Ray Crystallography
(I said light instead of Phase)
Your roommate is sick with the flu and is bashing microbes due to the fact that they caused her
sickness. Which of the following is not a fact to use to convince her that microbes are more good
than bad? - ANS✅✅Microbes produce toxins to fight against cell degradation
(I said Microbes are one of the body's first lines of defense against illness and injury)
If DNA is used to store information for many organisms, what statement is INCORRECT about the
RNA used by retroviruses to store their genomes? - ANS✅✅The retrovirus has an integrase that is
used to integrate its RNA into the genome of the cell
( I said The retrovirus has a 5' cap on the RNA because they only infect eukaryotes.. also have tail)
, Microbes have many impacts on the environments and on humans themselves, which of the
following is false? - ANS✅✅Most microbes cause disease i.e small pox
Which of the following is FALSE when referring to the Peptidoglycan of a bacterium? - ANS✅✅Its
tightly wound mesh-like structure results in a highly selective barrier
(I said Its structure is held together by crosslinking peptides)
Why was there a large amount of time between when Thonis Philipszoon discovered microbes and
when we began to cultivate and understand them? - ANS✅✅No suitable methods had yet been
developed that permitted cultivation of large populations.
( I said effective visualizing instruments were not available)
If Thonis Philipszoon had discovered microbes during the industrial revolution, would the cultivation
and understanding of microbes have began sooner? - ANS✅✅Indeterminable; while the resources
would be available, we would not know if the inclination to study microbes would take time to
develop or result immediately after Thonis' discovery.
Microorganisms are important for our health because - ANS✅✅bacterial infections cause about
25% of deaths worldwide
A rod-shaped cell has a mutation such that when the temperature is raised above 37°C, it can no
long produce FtsZ. If you grew these cells at 40°C and then observed them via a Gram stain. You
would see - ANS✅✅Filaments (longer rods than normal)
(I said Small coccus-shaped (spherical) cells)
With a living microbe that may be transparent, which type of microscope will provide a higher
quality image without staining or killing the specimen? - ANS✅✅Phase-Contrast Microscope
( I said Fluorescent)
Who discovered the reason for wine souring and why was this discovery significant? -
ANS✅✅Pasteur; it proved that microbes cause infection
( I said Pasteur; it proved wine was souring due to a chemical reaction)
All of the following are true statements about the bacterial membranes except - ANS✅✅A
membrane with lots of unsaturated fatty acids will be less permeabe
( I said The outer membrane has porins that allow ions like Na+ to easily pass through)
