Portage Microbiology Exam VERIFIED |ALREADY GRADED A+
VERIFIED
A micrometer is defined as - ANS10^-6
A nanometer is defined as - ANS10^-9
Assuming a constant (non-adjustable) light source power, identify the part of the
microscope you would adjust to limit the amount of light entering the microscope
(multiple choice) - ANSThe iris diaphragm
Assuming a fixed ocular, identify the part of the microscope you would adjust to
enhance the magnification of a sample - ANSObjective
Contrast (short answer) - ANSDifference in light absorbance between two objects. Poor
contrast gives a high background and makes the visualization of multiple objects
difficult.
Gram-Negative cells appear _____ in color due to a _____ peptidoglycan layer in the
cell wall (fill in the blanks) - ANSPink, thin
Gram-Positive cells appear _____ in color due to a _____ peptidoglycan layer in the cell
wall (fill in the blanks) - ANSPurple, thick
Identify what type of electron microscope was used to capture the following image and
explain your choice - ANSA: TEM, shows 2-D rendering
B: SEM shows 3-D shell models
Label the following unmarked microscope components by matching it with the
components provided - ANS1. Eyepiece
2. Neck
3. Fine adjustment knob
4. Objective
5. Stage
6. Base
Name one substance capable of chemically fixing cells to a slide -
ANSParaformaldehyde, ethanol, or methanol
Resolution (short answer) - ANSDistance between two objects at which the objects still
can be seen as separate. Poor or low resolution means two (or more) objects may
appear as one
This type of microscope can provide detailed images of live cells without staining (given
list of microscopes) - ANSPhase-Contrast
,Portage Microbiology Exam VERIFIED |ALREADY GRADED A+
VERIFIED
This type of microscope is best suited for visualizing GFP, RFP and YFP proteins (given
list of microscopes) - ANSFlourescence
This type of microscope is capable of capturing images in multiple focal planes
rendering specimen in 3D (given list of microscopes) - ANSConfocal
This type of microscope is used to greatly increase the contrast between samples and
background by reflecting light off of the specimen (given list of microscopes) - ANSDark
Field
True or False: A cell that is adherent, flat, and unstained is easily identified using bright
field microscopy - ANSFalse. Adherent, flat cells are almost invisible due to the limits on
both resolution and contrast
True or False: A nanometer is longer than a micrometer - ANSFalse
True or false: following the decolorization step of the Gram stain, Gram negative
bacteria will appear colorless - ANSTrue
True or False: If a patient is suspected of having malaria, a Giemsa stain would be an
appropriate differential test to perform - ANSTrue. Giemsa stains are often used in the
clinical setting to aid in the diagnosis of blood parasites
True or False: If you wish to study the motility of an organism you cannot heat fix, but
you can chemically fix the specimen - ANSFalse. Both heat and chemical strategies will
kill the cell, making motility observations impossible
True or False: Staining is often required to image a cell that is adherent and flat (thin) -
ANSTrue
True or False: The distinguishing characteristic of Gram_negative bacteria is the
presence of LPS in the outer membrane - ANSTrue
What is the total magnification of a sample imaged with a 60x objective and a 10x
eyepiece? (short answer) - ANS60 x 10 = 600x magnification
Which of the following could be seen clearly by the unaided eye? (multiple choice) -
ANSProtozoa with diameter of 150um and skin cell with diameter of 1500 um (have to
be greater than 100um
You suspect a patient may have TB. Once a sample has been obtained, it is sent off to
the lab for an acid-fast stain. If the patient were infected with TB, describe what you
would expect to see on the stained side - ANSYou would expect to see red cells (TB+)
on a blue background (TB negative)
, Portage Microbiology Exam VERIFIED |ALREADY GRADED A+
VERIFIED
You want to observe the size and shape of a cell. What is the easiest staining technique
that you could perform? Name at least one dye you would use during this process -
ANSSimple stain. You could use any of the following: methylene blue, crystal violet,
safranin, or fuschinamphipathic phospholipids - ANSThe cell membrane is a bilayer
composed primarily of ________ _________, meaning they contain a polar hydrophilic
(water loving) head group and a non-polar hydrophobic (water fearing) tail region.
Animalia - ANSAll microorganisms in this category are heterotrophic, meaning they are
incapable of producing their own energy, must absorb (consume) nutrients from the
environment, and have the general characteristic of motility (the ability to move).
Animalia, plantae, fungi, protista - ANSWhat are the four main classifications of
Eukarya?
archaea - ANSThey are able to survive in extremely harsh environmental conditions
such as high salt levels, acid conditions, high temperatures and oxygen-poor conditions.
capsid - ANSa membrane-like structure that contains genetic material found in viruses
chloroplast - ANS(plants only; site of photosynthesis
Coccus, bacillus, vibrio, spirillum - ANSmain morphologies of bacteria
cytoplasm - ANS
disaccharide - ANSsucrose is an example of a _______
DNA - ANScontains a vast amount of hereditary information and is responsible for the
inheritable characteristics of living organisms
endoplasmic reticulum - ANSsite of protein synthesis
fungi - ANScan be either multicellular or unicellular microorganisms, heterotrophic,
presence of chitin, a derivative of glucose, in their cell walls, ex. yeast or molds and
mushrooms
glycogen - ANSpolysaccharide in animal cells that consists of many glucose monomers
Golgi body - ANS
Golgi complex - ANSresponsible for protein modification and distribution
hydrophilic - ANSthe polar heads are
hydrophobic - ANSthe non polar tails are
VERIFIED
A micrometer is defined as - ANS10^-6
A nanometer is defined as - ANS10^-9
Assuming a constant (non-adjustable) light source power, identify the part of the
microscope you would adjust to limit the amount of light entering the microscope
(multiple choice) - ANSThe iris diaphragm
Assuming a fixed ocular, identify the part of the microscope you would adjust to
enhance the magnification of a sample - ANSObjective
Contrast (short answer) - ANSDifference in light absorbance between two objects. Poor
contrast gives a high background and makes the visualization of multiple objects
difficult.
Gram-Negative cells appear _____ in color due to a _____ peptidoglycan layer in the
cell wall (fill in the blanks) - ANSPink, thin
Gram-Positive cells appear _____ in color due to a _____ peptidoglycan layer in the cell
wall (fill in the blanks) - ANSPurple, thick
Identify what type of electron microscope was used to capture the following image and
explain your choice - ANSA: TEM, shows 2-D rendering
B: SEM shows 3-D shell models
Label the following unmarked microscope components by matching it with the
components provided - ANS1. Eyepiece
2. Neck
3. Fine adjustment knob
4. Objective
5. Stage
6. Base
Name one substance capable of chemically fixing cells to a slide -
ANSParaformaldehyde, ethanol, or methanol
Resolution (short answer) - ANSDistance between two objects at which the objects still
can be seen as separate. Poor or low resolution means two (or more) objects may
appear as one
This type of microscope can provide detailed images of live cells without staining (given
list of microscopes) - ANSPhase-Contrast
,Portage Microbiology Exam VERIFIED |ALREADY GRADED A+
VERIFIED
This type of microscope is best suited for visualizing GFP, RFP and YFP proteins (given
list of microscopes) - ANSFlourescence
This type of microscope is capable of capturing images in multiple focal planes
rendering specimen in 3D (given list of microscopes) - ANSConfocal
This type of microscope is used to greatly increase the contrast between samples and
background by reflecting light off of the specimen (given list of microscopes) - ANSDark
Field
True or False: A cell that is adherent, flat, and unstained is easily identified using bright
field microscopy - ANSFalse. Adherent, flat cells are almost invisible due to the limits on
both resolution and contrast
True or False: A nanometer is longer than a micrometer - ANSFalse
True or false: following the decolorization step of the Gram stain, Gram negative
bacteria will appear colorless - ANSTrue
True or False: If a patient is suspected of having malaria, a Giemsa stain would be an
appropriate differential test to perform - ANSTrue. Giemsa stains are often used in the
clinical setting to aid in the diagnosis of blood parasites
True or False: If you wish to study the motility of an organism you cannot heat fix, but
you can chemically fix the specimen - ANSFalse. Both heat and chemical strategies will
kill the cell, making motility observations impossible
True or False: Staining is often required to image a cell that is adherent and flat (thin) -
ANSTrue
True or False: The distinguishing characteristic of Gram_negative bacteria is the
presence of LPS in the outer membrane - ANSTrue
What is the total magnification of a sample imaged with a 60x objective and a 10x
eyepiece? (short answer) - ANS60 x 10 = 600x magnification
Which of the following could be seen clearly by the unaided eye? (multiple choice) -
ANSProtozoa with diameter of 150um and skin cell with diameter of 1500 um (have to
be greater than 100um
You suspect a patient may have TB. Once a sample has been obtained, it is sent off to
the lab for an acid-fast stain. If the patient were infected with TB, describe what you
would expect to see on the stained side - ANSYou would expect to see red cells (TB+)
on a blue background (TB negative)
, Portage Microbiology Exam VERIFIED |ALREADY GRADED A+
VERIFIED
You want to observe the size and shape of a cell. What is the easiest staining technique
that you could perform? Name at least one dye you would use during this process -
ANSSimple stain. You could use any of the following: methylene blue, crystal violet,
safranin, or fuschinamphipathic phospholipids - ANSThe cell membrane is a bilayer
composed primarily of ________ _________, meaning they contain a polar hydrophilic
(water loving) head group and a non-polar hydrophobic (water fearing) tail region.
Animalia - ANSAll microorganisms in this category are heterotrophic, meaning they are
incapable of producing their own energy, must absorb (consume) nutrients from the
environment, and have the general characteristic of motility (the ability to move).
Animalia, plantae, fungi, protista - ANSWhat are the four main classifications of
Eukarya?
archaea - ANSThey are able to survive in extremely harsh environmental conditions
such as high salt levels, acid conditions, high temperatures and oxygen-poor conditions.
capsid - ANSa membrane-like structure that contains genetic material found in viruses
chloroplast - ANS(plants only; site of photosynthesis
Coccus, bacillus, vibrio, spirillum - ANSmain morphologies of bacteria
cytoplasm - ANS
disaccharide - ANSsucrose is an example of a _______
DNA - ANScontains a vast amount of hereditary information and is responsible for the
inheritable characteristics of living organisms
endoplasmic reticulum - ANSsite of protein synthesis
fungi - ANScan be either multicellular or unicellular microorganisms, heterotrophic,
presence of chitin, a derivative of glucose, in their cell walls, ex. yeast or molds and
mushrooms
glycogen - ANSpolysaccharide in animal cells that consists of many glucose monomers
Golgi body - ANS
Golgi complex - ANSresponsible for protein modification and distribution
hydrophilic - ANSthe polar heads are
hydrophobic - ANSthe non polar tails are
