Microbiology: Pre-Lab Quizzes (1-7)
Mark all that have a prokaryotic cell type
Mark all that have a eukaryotic cell type
Mark all that are animals
Which gene is used to molecularly identify bacteria and archaea?
16s rRNA
Which gene is used to molecularly identify Eukarya?
ITS
Which objective lens should be in position when placing a slide onto the stage or off the stage?
4x
Total magnification power is calculated by multiplying the objective power in use by
the ocular power (10x)
Which part of the microscope can be changed to make a brightfield microscope a darkfield microscope?
Condenser
Which part of the microscope can be changed to make a brightfield microscope a phase contrast microscope?
Diaphragm
When converting the field of view from mm to μm, the mm measurement is multiplied by which value?
1000
The simple staining method that uses one of the acidic dyes such as nigrosin or India ink
Negative Staining
The simple staining method that uses a single acidic or basic stain
Positive staining
The differential staining method that uses crystal violet and safranin
Gram staining
The differential staining method that uses fuchsin and methylene blue
Acid-fast staining
The differential staining method that uses malachite green and safranin
Spore staining
With negative staining, what color will bacterial colonies appear as?
White
With spore staining, endospores will appear as what color?
Green
With acid-fast staining, Mycobacterium (acid-fast bacteria) will stain which color because of the presence of mycolic acid?
Red
With Gram staining, Gram positive bacteria will stain as which color?
Purple/blue
With Gram staining, Gram negative bacteria will stain as which color?
Pink
Agar, a molecule derived from red algae, is an important ingredient in which type of media?
Semi-solid
This type of media contains one or more agents that inhibit the growth of certain microbes but not another
Selective
These media are designed to grow a broad spectrum of microbes that do not have special growth requirements
General purpose
This type of media can grow several types of microbes but are designed to bring out visible differences among those microbes
Differential
This media is a general purpose media used for nonfastidious microbes including many bacteria and fungi
Nutrient Agar or Broth (NA & NB)
This selective and differential media is used to isolate enteric bacteria that hydrolyze urea
Eosin Methylene Blue Agar (EMB)
This media is a general purpose media used for bacteria
Trypticase Soy Agar (TSA)
This media is a general purpose media used for fungi
Potato Dextrose Agar (PDA)
This selective and differential media is used to isolate enteric bacteria that ferment lactose
MacConkey's Agar
This selective and differential media is used to isolate Staphylococcus
Mannitol Salt Agar (MSA)
MSA is a selective medium for which bacteria because of the high salt concentration?
Staphylococcus sp.
MSA will turn what color when the bacterium ferments the mannitol and produces acid?
Yellow
EMB agar is selective for which bacteria?
Gram-negative intestinal pathogenes
EMB agar is selective because only bacteria that ferment this sugar produce colored colonies
Lactose
Colonies of E. coli on EMB agar will produce what color colonies?
Green
Colonies of Enterobacter aerogenes on EMB agar will produce what color colonies?
Pink
MacConkey's agar is selective for what group of bacteria?
Salmonella sp.
Colonies of coliform bacteria on MacConkey's agar will produce what color colonies?
Red
The ingredients of crystal violet and bile salts inhibit which group of bacteria?
Gram-positive intestinal pathogenes
If the nutrient agar is neither selective or differential, then the colonies of the different bacteria should look
Similar
Cell division for bacteria is known as
Binary fission
In this phase, the cells are adjusting to their environment
Lag phase
In this phase, the cells reach the maximum rate of cell division
Log phase
In this phase, the cells will stop growing or grow very slowly
Stationary phase
In this phase, limiting factors intensify becoming detrimental to any cell growth
Death phase
Generation time should be measured during which phase?
Log phase
A dilution of 1:10,000,000 is equivalent to 10 to which exponent?
7
A dilution of 1:1,000,000 is equivalent to 10 to which exponent?
6
When plating out a serial dilution series, which solution would have the fewest colony forming units?
1:10,000,000
An increase in optical density or absorbance indicates _______ microbial organisms
an increase in the number of
Bacteria that must grow in oxygen because their metabolism requires oxygen
Obligate aerobes
Bacteria that have a flexible metabolism for oxygen conditions
Facultative anaerobes
Bacteria that cannot grow in an oxygenated environment
Obligate anaerobes
Many bacteria pathogens have an optimal growth between 35°C and 40°C, these are classified as
Mesophiles
Which bacteria's colonies change color from white (higher temperature) to red (lower temperature)?
Serratia
pH refers to what?
Concentration of hydrogen ions
A cell that has fewer solutes than its environment
Hypotonic
A cell that has the same solute concentration as its environment
Isotonic
A cell that has more solutes than its environment
Hypertonic
A microbe such as Halobacterium salinarium thrives in high salt concentration environments is known as
Obligate halophile