Microbiology HOL lab final
Agent naturally produced by microorganisms.
Antibiotic
Agent artificially synthesized or manipulated from other products.
Antimicrobial
Order the steps of Gram staining into the proper sequence. -Decolorizer dehydrates Gram-positive cell walls. -Safranin is applied to the slide. -Iodine is applied to the slide. -Crystal violet is applied to heat fixed cells.
-Crystal violet is applied to heat fixed cells. -Iodine is applied to the slide. -Decolorizer dehydrates Gram-positive cell walls. -Safranin is applied to the slide.
Order the steps for performing a dilution series. -Calculate the concentration in the original tube. -Determine the dilutions of the dilution tubes (first series of dilutions). -Determine which plate is the countable plate.
-Determine the dilutions of the dilution tubes (first series of dilutions). -Determine which plate is the countable plate. -Calculate the concentration in the original tube.
When one bacterial cell undergoes binary fission, there will be _____ cells present on the 5th generation. 5 8 16 None of the above
16
Performing a 1:8 dilution from the original sample 3 times would produce a dilution of _____. 1:24 1:512 1:4096 None of the above
1:512
Plates with _____ colonies per plate are used to calculate CFUs. 10-30 30-300 20-100 None of the above
30-300
A viable plate has a count of 95 colonies produced from 0.125 mL of a 10-4 dilution of the original sample. The original contains _____ CFU/mL. 760 12,000 7,600,000 None of the above
7,600,000
The measure of the light intensity absorbed by a sample
Absorbance
Solid media used to isolate microbes.
Agar plate
Aseptic technique includes _____ . working quickly and efficiently around open media containers not talking or breathing over open media containers washing hands before and after working with media All of the above
All of the above
Aseptic techniques are necessary to _____. maintain safety isolate pure cultures prevent the spread of unwanted microbes All of the above
All of the above
Mixed-acid fermentation produces _____. acetic acid ethanol hydrogen gas All of the above
All of the above
Slides should be rinsed after applying _____ during the Gram staining process. crystal violet iodine decolorizer All of the above
All of the above
The inoculation loop must be sterilized _____ when creating a streak plate. before use between use in each quadrant after completing all quadrants All of the above
All of the above
When transferring microbes from a broth to a plate, the inoculation loop should be sterilized _____. before placing in broth after spreading microbes on the agar surface prior to disposal All of the above
All of the above
____ is a genus that produces antibiotics. Bacillus Cephalosporium Streptomyces All of the above
All of the above
_____ is a common, harmless microbe used in laboratory studies. Escherichia coli Saccharomyces cerevisiae Staphylococcus epidermidis All of the above
All of the above
_____ is an example of a direct stain. Crystal violet Methylene blue Safranin All of the above
All of the above
_____ are rod-shaped bacteria 0.5 - 20 µm in length. Cocci Bacilli Spirillum All of the above
Bacilli
Agent that kills bacterial upon exposure.
Bactericidal
Agent that slows the growth of bacteria.
Bacteriostatic
Asexual reproduction resulting in two daughter cells
Binary fission
Liquid media used to increase the number of microorganisms.
Broth
A spherical bacteria with a diameter of approximately 0.5 µm
Coccus
Clump of genetically identical microorganisms.
Colony forming unit
Describes individual colonies on a plate's surface
Colony forming unit
Acidic stain repelled by the cell's surface
Congo red
_____ are asexually-produced spores of the Penicillium fungus. Aspergillus Bacillus Conidia None of the above
Conidia
_____ is a rod-shaped bacteria important to the study of genetics and evolution. Escherichia coli Saccharomyces cerevisiae Staphylococcus epidermidis All of the above
Escherichia coli
Visible area of a slide that can be observed
Field of view
Binds with bacterial ribosomes to prevent cell growth and cell division.
Gentamicin
Gentamicin is synthesized by a _____. Gram-negative bacteria Gram-positive bacteria black mold None of the above
Gram-positive bacteria
Instrument used for spreading microorganisms across a streak plate.
Inoculation loop
Targets DNA gyrase, preventing DNA replication within a cell.
Novobicin
Held by the turret closest to the stage, and range in power from 4x to 100x magnification
Objective lens
Ocular lens
Ocular lens
*know the different parts of the microscope
Ocular lens, objective lens, stage, illuminator, arm, coarse focus knob, fine focus knob, base
Disrupts cell wall stability, eventually leading to cell lysis.
Penicillin
The mold that Alexander Fleming observed preventing bacterial growth was _____. Aspergillus Streptococcus pyogenes Penicillium notatum None of the above
Penicillium notatum
Mesh-like polymer present in bacteria cell walls
Peptidoglycan
Single-celled fungi used for studies involving fermentation, genetics, and aging.
Saccharomyces cerevisiae
_____ stains Gram-negative bacteria pink. Crystal violet Iodine Safranin All of the above
Safranin
Calculated by multiplying the magnification of the ocular lens with the objective lens
Total magnification factor
A compound microscope is a type of optical microscope. True False
True
Agar is a solid media used in both slants and plates. True False
True
All equipment and work surfaces should be cleaned with a bleach solution after contacting microbe cultures. True False
True
Bacteriostatic antibiotics cause an inhibition of growth rather than cell lysis and death. True False
True
Butanediol fermentation produces weaker acids than mixed-acid fermentation. True False
True
Depth of field refers to the distance range that is in focus at a given time. True False
True
Differential staining uses two or more dyes to stain structural components of a cell. True False
True
Gram-positive cells have a thick outer cell wall composed of peptidoglycan. True False
True
Many types of bacteria have gained resistance to antimicrobials at an astonishing rate. True False
True
Morphology can be used to identify microorganisms with or without the use of a microscope. True False
True
Negative staining results in a colorless cell on a stained background. True False
True
Novobiocin is a bacteriostatic, narrow-spectrum antibiotic. True False
True
Turbidity and flocculence are indicators of microbial growth in liquid media. True False
True
When calculating total magnification of a microscope, both the ocular lens and the objective lens should be considered. True False
True
Methyl red is a pH indicator that turns red in _____ conditions. acidic neutral basic None of the above
acidic
Agar plates should be labeled on the _____. lid bottom side All of the above
bottom
The charge of _____ determines how dyes interact with bacterial cells during staining. chromophores plasma membranes porins None of the above
chromophores
A viable plate count is a method of calculating the number of cells in a dilution by the counting the number of _____ on agar plates. cells colonies species All of the above
colonies
A spreader is used when inoculating a Kirby-Bauer diffusion plate to _____. isolate individual bacteria colonies create a uniform bacterial lawn confine bacteria to one section of the plate None of the above
create a uniform bacterial lawn
If the magnification of a compound microscope is increased from 10x to 100x, the field of view will _____. decrease increase by 10x increase by 100x None of the above
decrease
The _____ sits below the stage and varies the field for viewing the specimen. diaphragm coarse adjustment knob base None of the above
diaphragm
In binary fission, bacterial cells grow _____. exponentially linearly negatively None of the above
exponentially
The main component of an optical microscope that is used to focus an image at a high power of magnification is the _____. coarse adjustment knob diaphragm fine adjustment knob None of the above
fine adjustment knob
Tryptic Soy Agar (TSA) is a _____ media. general purpose liquid selective liquid general purpose solid None of the above
general purpose solid
Catalase neutralizes the harmful effects of _____. hydrogen peroxide butanediol acetoin None of the above
hydrogen peroxide
Biochemical tests are designed to identify _____ properties of microbes. morphologic metabolic motility All of the above
metabolic
Penicillin is produced by a _____. bacteria mold virus All of the above
mold
To determine the number of CFUs in the original culture, the number of colonies on the viable plate is _____ the total dilution factor of that plate. added to multiplied by divided by None of the above.
multiplied by
Penicillin disrupts the formation of bacterial cell walls by inhibiting the formation of _____ cross-links. porin protein peptidoglycan None of the above
peptidoglycan
Bacteriostatic agents treat infections by _____. cell wall lysis inhibiting ribosomal activity preventing cell division None of the above
preventing cell division
Gentamicin binds with bacterial _____. ribosomes cell walls mitochondria All of the above
ribosomes
The slide is placed on the _____ of an optical microscope. stage turret base None of the above
stage
Novobiocin is a bacteriostatic, narrow-spectrum antibiotic that targets _____ in some Gram-positive bacteria. DNA gyrase RNA primase Okazaki fragments None of the above
DNA gyrase
_____ washes dyes from Gram-negative bacteria. Crystal violet Iodine Decolorizer None of the above
Decolorizer
Distance range that is in focus at a given time
Depth of field
A dye that stains only the cell leaving the background colorless
Direct stain
The number of individuals doubles each generation
Exponential growth
A pure plated culture should exhibit colony forming units with two or more morphologies. True False
False
An antibiotic is a synthetic drug produced in a laboratory. True False
False
Binary fission is a method of sexual reproduction where a single cell (parent cell) will split into four cells (daughter cells). True False
False
Gram-positive bacteria have an outer cell membrane containing endotoxins. True False
False
Heat fixing is required for the negative staining process. True False
False
Resistant bacteria will exhibit a large zone of inhibition during a Kirby-Bauer diffusion test. True False
False
Streak plating is performed by pouring broth onto agar plates. True False
False
The depth of field is independent of the total magnification factor. True False
False
The effective zone of inhibition is the same for all antibiotics. True False
False
The oil immersion lens provides optimal viewing of large specimens. True False
False
To create a series of dilutions, an identical volume of stock (undiluted) solution is added to each of the dilution test tubes. True False
False
When creating a wet-mount slide, an individual should drop the cover slip on the top of a water droplet placed on the slide without touching it to the slide first. True False
False
Zones of inhibition should be measured after they exceed 25 mm. True False
False
_____ exist only as single cells and do not form clusters or chains. Bacilli Cocci Spirillum All of the above
Spirillum
Normal flora bacteria used for studies involving osmotic pressure, antibiotic resistance, and biofilms.
Staphylococcus epidermidis
Rod-shaped bacterial cells linked to form a chain
Streptobacilli
_____ are bead-like chains of spherical cells. Tetrads Staphylococci Streptococci None of the above
Streptococci
Identify each statement as true or false. -Media containers should be stored away from children and pets. -Work surfaces should be sterilized with soap and water. -The caps and lids of media containers should be placed on countertops when working with cultures. -Open tubes and vials should be tilted away from the mouth and nose. -Aseptic techniques are designed to prevent the spread of microorganisms beyond the intended working environment. -Plates should be incubated agar side down.
True: -Media containers should be stored away from children and pets. -Aseptic techniques are designed to prevent the spread of microorganisms beyond the intended working environment. -Open tubes and vials should be tilted away from the mouth and nose. False: -Plates should be incubated agar side down. -Work surfaces should be sterilized with soap and water. -The caps and lids of media containers should be placed on countertops when working with cultures.
Cloudiness of a fluid caused by large numbers of particles/organisms
Turbidity
