Micro Lab 1-6 Quizzes
cell completely surrounded by flagella
Peritrichous
Which does NOT affect resolution? Select one: a. size of the specimen observed b. numerical aperture of the objective c. wave length of light d. ability to gather light
a. size of the specimen observed
Negative stains are created by staining the background of the specimen with which type of stain? Acidic or basic?
acidic
single flagellum at each pole
amphitrichous
The species we will be using to perform the endospore stain in lab all belong to which genus
bacillus
The endospore stain is a differential stain used to detect the presence and location of ________ in bacteria
endospores
Artificial media cannot be both selective and differential.
false
Bacteria grow in pure cultures in nature.
false
Cholera (Vibrio cholera) is spread via airborne transmission.
false
In order to inoculate a slant, use one quick stabbing motion about half way down and pull straight back out.
false
Normal flora can never become pathogenic
false
Obligate anaerobic bacteria can be cultured on an agar slant.
false
Simple staining distinguishes organisms based on their interactions with multiple stains, while differential staining uses a single dye to emphasize particular structures in the specimen.
false
The endospore stain is used to distinguish between Gram negative and Gram positive cells.
false
Viruses can be viewed with the compound light microscope.
false
For proper sterilization, the instrument used for sampling and for obtaining the inoculum should be sterilized for at least ________ seconds
five
Waxy substances present in the cell wall, basis for acid-fast reaction. Produces unusual permeability properties
mycolic acids
In differential staining, the cells retaining the counterstain are considered to be:
negative
MacConkey agar is selective for Gram (one word) bacteria
negative
Total magnification = magnification of the __________ lens times magnification of the objective lens
ocular
Many of the commensal or mutualistic strains inhabiting our bodies are __________ pathogens capable of producing a disease state if introduced into a suitable part of the body.
opportunistic
defined as the ability to quickly focus while switching from a lower power lens to a higher power lens with a minimal amount of adjustment, using the fine focus knob only.
parfocal
Phenylethyl alcohol is the selective agent in PEA that inhibits Gram negative organisms by breaking down their membrane ___________barrier, thus allowing leakage of cellular potassium and disrupting DNA synthesis.
permeability
Gram __________cells have larger amounts of peptidoglycan
positive
In differential staining, the cells retaining the first or primary stain are considered to be:
positive
The decolorizer (or decolorizing agent) removes the ___________ stain selectively, based on the presence or absence of specific characteristics.
primary
The extent to which a material slows transmission speed relative to empty space is called the _____________of that material and is an important concept to know when using a light microscope, especially at the 100x objective.
refractive index
______________ is the ability to tell that two separate points or objects are separate.
resolution
Potato dextrose agar and sabaround dextrose agar are both ______________for yeasts, molds, and fungi.
selective
This type of media promotes the growth of a specific microbe while inhibiting the growth of certain other microbes.
selective
If cells appear individually, their arrangement is described as being the same as their _________for example, the arrangement of a species appearing as individual rods is bacillus.
shape
For the Lab 1 experimental procedures, nutrient agar (NA) plates will be inoculated using which type of streak method?
simple streak
d. As we go from low (10X) to high power (100X), the microscopic field gets __________ and the image gets __________, so you will need more light to view the specimen.
smaller, darker
Dyes are often added to growth media to aid in the identification of microbes. What could be the purpose of a dye in this case?
to indicate the pH level of the media
A transparent specimen will ________ light.
transmit
A hospital acquired infection is also known as a nosocomial infection.
true
After incubation, when interpreting results, you should handle plates carefully, because condensation and/or contaminated water droplets could drip from the plates.
true
Capsule production increases virulence in some microbes by making them less vulnerable to phagocytosis.
true
Endospores are dehydrated and show no metabolic activity.
true
Gram negative organisms frequently inhibit growth of Gram positive organisms when they are cultivated together.
true
Streaking for isolation is a dilution technique used to obtain a pure culture from a mixed population of cells.
true
Transient flora can be found in the layer of skin called the epidermis.
true
a Gram positive bacillus will grow best on phenyl ethyl agar (PEA).
true
Some bacteria live inside hot springs, while others have been found under the ice in Antarctica. These are examples of the _____________________ of microorganisms.
ubiquity
A specimen viewed with the oil immersion objective lens would have a total magnification of:
1000x
Which objective lens requires the use of immersion oil?
100x
Peptidoglycan and teichoic acid form a molecular complex with:
Crystal violet/iodine
Which is the most common type of biological vector of human disease?
D.arthropods
_______________Agar is commonly used to test for the presence of coliforms in environmental samples, which would indicate fecal contamination and the possible presence of dangerous pathogens.
Eosin Methylene Blue (EMB)
The study of factors influencing occurrence, transmission, distribution, prevention and control of disease is called:
Epidemiology
may be misidentified due to small halos which form as a result of cell shrinkage
Glycocalyx capsules
two or more flagella at 1 or both poles of the cell
Lophotrichous
Name the organism (Genus and species) that causes the most hospital acquired infections. Note: Be sure to spell and format the name of the organism correctly.
Staphylococcus aureus
An example of potential contamination of microbial culture is: Select one: a. Forgetting to heat/sterilize loops b. Keeping agar plates open c. All of the other choices are correct. d. Placing test tube caps on bench tops
c. all of the choices are correct
Which of the following is NOT true about contamination? a. changes a pure culture to a mixed culture b. alters drug sensitivity tests c. is more likely to occur when using proper aseptic technique d. produces inaccurate test results
c. is more likely to occur when using proper aseptic technique
Bacterial smears must be heat fixed prior to performing all of the following staining procedures EXCEPT for which of the following? Select one: a. Acid Fast Stain b. Gram stain c. Negative stain d. Simple stain
c. negative stain
Both simple stains and negative stains enhance the contrast of cells and allow for the visualization of ________
cell shape
Which of the following controls the amount of light passing through a slide on the microscope stage
condenser lens
Capsules don't take up acidic or basic stains.Instead, cell is stained with _______________and background stained with ____________
crystal violet, India ink
You heat fix a bacterial smear for all of the following reasons EXCEPT: Select one: a. Adhere bacteria to the slide b. Kill the bacteria c. Inactivate bacterial enzymes d. Help the bacteria grow
d. help the bacteria grow
A good bacterial smear should be thinly visible to the naked eye and approximately the size of a ___________
dime
All of the following are included in the "Five I's" culturing microorganisms in a laboratory setting EXCEPT: Select one: a. Incubation b. identification c. inspection d. Inoculation e. infection f. Isolation
e. infection
dormant structure formed within a microbial cell as a survival mechanism to resist damage from environmental factors (UV light, heat, chemicals, dehydration), ONLY in Gram positive bacteria
endospore
A blanket from a child with chickenpox is likely to be contaminated with the virus that causes chickenpox (Varicella-zoster virus). What is the blanket called?
fomite
You perform a Gram stain on a specimen. Under the microscope you see spherical pink cells this would indicate the specimen is:
gram negative cocci
You perform a Gram stain on a specimen. Under the microscope, you see spherical purple cells. This observation would indicate that the specimen is:
gram positive cocci
This is the oldest and one of the most common forms of microbial control, which can kill microbes by altering their membranes and denaturing proteins.
heat
Free-living microorganisms do not reside on or in a specific plant or animal ___________ and are not known to cause disease.
host
What is used to decrease the amount of light that is refracted when using a compound light microscope to view a specimen at the highest level of total magnification?
immersion oil
The sampling instrument used for obtaining an inoculum is called a/an ________
inoculating loop
Which of the following is NOT an example of a non-living reservoir for pathogens?
intermediate hosts
Sterilize/incinerate the loop between each streaked section increases the chance of ________ colonies on an agar plate
isolating
When viewing a specimen through the microscope, if you want the specimen to move to the right within your field of vision, which direction should you move the stage?
left
___________ is the ability of a lens to enlarge the image of an object when compared to the real object
magnification
Mannitol Salt Agar (MSA) is differential for fermenters/ non-fermenters of __________
mannitol
_____________ (general term) are used to provide all essential nutrients needed in order to culture microorganisms in a laboratory setting.
media
single flagellum at one pole
monotrichous
The Acid Fast test is specific to which genus of bacteria?
mycobacterium
During optimal growth conditions, an endospore will germinate to form a (one word) cell.
vegetative
