Microbiology Lab Safety Quiz

Questions and Answers

What biosafety level are most microbes in our lab?

BSL-1 (correct)

BSL-4

BSL-3

BSL-2

According to Dr. Franklund, what is the most dangerous thing in our microbiology lab?

The microbes

Your lab partner

The bunsen burner (correct)

The incubators

What type of fire extinguisher does our lab have?

ABC (correct)

Foam

Halon

Where is our lab's tornado evacuation location?

The hallway Signup and view all the answers

What should you put down the sink in our lab?

Water Signup and view all the answers

What term refers to the edge of a colony?

Margin Signup and view all the answers

What term refers to a macroscopic pile of microscopic cells?

Colony Signup and view all the answers

Umbronate is an example of a colony's ___________.

Elevation Signup and view all the answers

The most common color of bacterial colonies is what?

Tan Signup and view all the answers

What solidifying agent is added to our plated media?

Agarose Signup and view all the answers

What is the maximum magnification using our microscopes?

1000 X Signup and view all the answers

What term refers to the ability to distinguish two objects as being separate from each other?

Resolution Signup and view all the answers

Which of our objective lenses has the most working distance?

4X Signup and view all the answers

How big is one ocular micrometer tick when using our 100X objective lens?

1 µm Signup and view all the answers

What is the purpose of immersion oil?

To reduce light loss and improve resolution Signup and view all the answers

How large are most bacteria?

1 to 5 µm Signup and view all the answers

What term refers to ball-shaped microbes found in chains?

Streptococci Signup and view all the answers

What term refers to spiral-shaped bacteria with axial filaments?

Spirochetes Signup and view all the answers

What term refers to rod-shaped bacteria?

Bacilli Signup and view all the answers

What term refers to ball-shaped bacteria that appear in packets of eight cells?

Sarcina Signup and view all the answers

What is the primary stain of the Gram stain?

Crystal violet Signup and view all the answers

What color is a properly stained Gram negative bacterium?

Pink Signup and view all the answers

Who invented the Gram stain?

Hans Christian Gram Signup and view all the answers

What would happen if you apply the destain for too long in the Gram stain?

Both Gram positive and negative cells would be pink Signup and view all the answers

What is the function of iodine in the Gram stain?

Mordant Signup and view all the answers

What is the main function of a microbial capsule?

Evade phagocytes Signup and view all the answers

What are most microbial capsules made of?

Polysaccharides Signup and view all the answers

What did we stain the background with in our capsule stains?

India ink Signup and view all the answers

What type of microbe is Cryptococcus neoformans?

Fungus Signup and view all the answers

How did capsules appear in our capsule stain?

Clear areas around the cells Signup and view all the answers

What is the purpose of a bacterial endospore?

Survival Signup and view all the answers

What was the primary stain in the endospore stain?

Malachite green Signup and view all the answers

What was the mordant in the endospore stain?

Heat Signup and view all the answers

Which pair microbes make endospores?

Bacillus and Clostridium Signup and view all the answers

What color did endospore stain in our lab?

Green Signup and view all the answers

Why do we call this the acid fast stain?

The color does not come out in an acid wash Signup and view all the answers

Which acid fast staining technique did we use?

Kinyoun Signup and view all the answers

Which two diseases are typically caused by acid fast bacteria?

Tuberculosis and leprosy Signup and view all the answers

What color did our acid fast bacteria appear?

Dark red Signup and view all the answers

What was the secondary stain in the acid fast procedure?

Methylene blue Signup and view all the answers

What structure do most bacteria use for motility in liquid media?

Flagella Signup and view all the answers

What term refers to microbes with a single flagellum at one end?

Monotrichous Signup and view all the answers

What term refers to bacteria with tufts of flagella at their end?

Lophotrichous Signup and view all the answers

What term refers to bacteria with flagella at both of their ends?

Amphitrichous Signup and view all the answers

What term refers to bacteria that have flagella all around their cell margin?

Peritrichous Signup and view all the answers

If you put 2 ml of sample into 8 ml of diluent, what is the tube dilution factor?

5X Signup and view all the answers

If you have three tubes with 1 ml of diluent in each and you sequentially transfer 1 ml of sample to each (i.e., 1 ml to #1, then 1 ml from #1 to #2 and 1 ml from #2 to #3), what is the SDF for tube 3?

8X Signup and view all the answers

If you dilute a sample 1000X, plate 0.1 ml, and observe 150 colonies the next day, how many cfu/ml were in the original culture?

1,500,000 Signup and view all the answers

If you have a culture with 50,000,000 cfu/ml and you serially dilute it by transferring 1 ml into 9 ml of diluent five times, how many colonies would you expect if you plate 0.2 ml?

100 Signup and view all the answers

Assume that you have a culture with 4,000,000 cfu/ml and you plated 0.5 ml. The next day you observe 200 colonies. How much was this culture diluted prior to plating?

10,000 Signup and view all the answers

What kind of microbes are bacteriophage?

Acellular Signup and view all the answers

What term refers to the protein coat that surrounds the phage genome?

Capsid Signup and view all the answers

What are these holes referred to as?

Plaques Signup and view all the answers

Assume that you dilute a phage stock by adding 0.1 ml to 0.9 ml in 7 tubes sequentially and then plate 0.1 ml on host cells. If you saw 100 holes on the plate the next day, how many pfu/ml were in your stock?

1 x 10^10 Signup and view all the answers

In our lab, how many drops do we assume that it takes to make 1 ml?

30 Signup and view all the answers

What are the clear areas around this disk called?

Zone of inhibition Signup and view all the answers

What is the target of tetracycline's action?

Ribosome Signup and view all the answers

What group of compounds includes aldehydes?

Alkylators Signup and view all the answers

When you use isopropanol on your skin, it is acting as __________.

An antiseptic Signup and view all the answers

Which of the following compounds is a surfactant?

Roccal Signup and view all the answers

Identify this protozoan pathogen.

Entamoeba Signup and view all the answers

Identify this protozoan pathogen.

Plasmodium Signup and view all the answers

Identify this protozoan pathogen.

Balantidium Signup and view all the answers

Identify this protozoan pathogen.

Trichomonas Signup and view all the answers

Identify this protozoan pathogen.

Giardia Signup and view all the answers

What biomolecule are fungal cell walls composed of?

Chitin Signup and view all the answers

Which fungus does this image represent?

Syncephalatrum Signup and view all the answers

Which fungus does this image represent?

Penicillium Signup and view all the answers

Which fungus does this represent?

Rhizopus Signup and view all the answers

Which fungus does this image represent?

Fusarium Signup and view all the answers

What type of microbe grows best between 20 and 40°C?

Mesophile Signup and view all the answers

What type of microbe grows best between pH 3 and pH 4?

Acidophile Signup and view all the answers

What type of microbe will only grow in the presence of 5 to 15% NaCl?

Halophile Signup and view all the answers

What pH would a neutrophile grow best at?

7 Signup and view all the answers

Which of these best describes most bacterial pathogens?

Neutrophile and Mesophile Signup and view all the answers

What is the oxygen indicator found in Brewer's anaerobic agar?

Methylene blue Signup and view all the answers

In a GasPak jar, what is oxygen converted into?

Water Signup and view all the answers

What type of growth is exhibited in this fluid thioglycollate tube?

Facultative anaerobe Signup and view all the answers

What type of growth is exhibited in this fluid thioglycollate tube?

Obligate aerobe Signup and view all the answers

What type of microbe would grow inside a GasPak jar but not outside of it?

Obligate anaerobe Signup and view all the answers

What percent of a microbial population will remain after one D-value has transpired?

50% Signup and view all the answers

If we hold the time of exposure constant at 10 minutes and it required 80°C to achieve sterilization, 80°C is the ___________.

Thermal death point Signup and view all the answers

If we hold the temperature constant at 70°C and it requires 23 minutes to achieve sterilization, 23 minutes is the ______.

Thermal death time Signup and view all the answers

Why is Bacillus cereus so resistant to killing by heat?

It makes endospores Signup and view all the answers

What term refers to the complete killing of all microbes on a surface?

Sterilization Signup and view all the answers

Which of these microbes is most resistant to UV killing?

Bacillus Signup and view all the answers

Which of these has the shortest wavelength?

UVC Signup and view all the answers

Which of these is the most germicidal wavelength of UV light?

260 nm Signup and view all the answers

What sort of cellular damage is caused by UV light?

T-T dimers Signup and view all the answers

What type of UV light is used in tanning booths (hopefully)?

UVA Signup and view all the answers

What biochemical test are all coliforms positive for?

Lactose fermentation Signup and view all the answers

What color is a positive urease test?

Pink Signup and view all the answers

What reaction would a TSI tube show if glucose was fermented, but not sucrose or lactose?

K/A Signup and view all the answers

Which amino acid is broken down in a positive indole test?

Tryptophan Signup and view all the answers

What color does a positive citrate test turn?

Blue Signup and view all the answers

What compound is broken down in a catalase test?

Hydrogen peroxide Signup and view all the answers

What inhibitory molecule is found in EF broth?

Sodium azide Signup and view all the answers

What type of hemolysis results in complete clearing on blood agar?

Beta Signup and view all the answers

What antibiotic is found on our A disks?

Bacitracin Signup and view all the answers

What type of media is mannitol salt agar?

Selective and differential Signup and view all the answers

Study Notes

Biosafety and Lab Safety

Most microbes in the lab are classified as BSL-1.
The most dangerous item in the microbiology lab is the Bunsen burner.
The lab has an ABC type fire extinguisher.
Tornado evacuation location is designated as the hallway.
Only water should be disposed of down the sink in the lab.

Colony Characteristics and Microscopy

The edge of a colony is referred to as the margin.
A macroscopic pile of microscopic cells is called a colony.
Umbronate describes a colony's elevation.
The most common color for bacterial colonies is tan.
Agarose serves as the solidifying agent in plated media.
The maximum magnification using lab microscopes is 1000X.
Resolution refers to the ability to distinguish two separate objects.

Bacterial Morphology

Rod-shaped bacteria are termed bacilli.
Ball-shaped bacteria in chains are called streptococci.
Spiral-shaped bacteria with axial filaments are spirochetes.
Ball-shaped bacteria that appear in packets of eight cells are termed sarcina.

Gram Staining Procedure

The primary stain in the Gram stain process is crystal violet.
Gram-negative bacteria appear pink after proper staining.
The Gram stain was invented by Hans Christian Gram.
If the destain process is prolonged, both Gram-positive and negative cells appear pink.
Iodine functions as a mordant in the Gram staining process.

Microbial Structures and Functions

The primary function of a microbial capsule is to evade phagocytes.
Capsules are typically made of polysaccharides.
Bacterial endospores are primarily used for survival.
Endospores appear green when stained with malachite green.

Acid-Fast Staining

The acid-fast stain is so named because the primary stain does not wash out in acid.
Kinyoun staining technique is used for acid-fast bacteria.
Common diseases caused by acid-fast bacteria include tuberculosis and leprosy.
Acid-fast bacteria appear dark red after staining, with methylene blue as the secondary stain.

Microbial Mobility

Most bacteria utilize flagella for motility in liquid media.
Bacteria with a single flagellum at one end are called monotrichous.
Bacteria with flags at both ends are referred to as amphitrichous, while those with tufts are lophotrichous.

Dilution and Colony Counting

To calculate tube dilution factor: when 2 ml is put into 8 ml of diluent, the factor is 5X.
A culture diluted 1000X and yielding 150 colonies results in an original concentration of 1,500,000 cfu/ml.
Serial dilutions can be calculated based on the amount transferred and plated.

Bacteriophage and Viral Structure

Bacteriophages are classified as acellular microbes.
The protein coat surrounding the phage genome is termed capsid.
Clear areas around disks on agar plates are known as zones of inhibition.

Microbial Resistance and Sterilization

Sterilization refers to complete killing of all microbes on a surface.
Bacillus cereus is known for its resistance to heat due to endospore formation.
Germicidal effectiveness of UV light is highest at a wavelength of 260 nm, producing T-T dimers in DNA.

Biochemical Testing

All coliforms test positive for lactose fermentation, indicative of their metabolic capability.
A positive urease test results in a pink coloration.
TSI (Triple Sugar Iron) test shows K/A if only glucose is fermented.
Indole test detects the breakdown of tryptophan, producing a positive result when the indicator changes color.
The hemolytic pattern of complete clearing on blood agar is classified as beta hemolysis.

Growth Conditions for Microbes

Mesophiles thrive best at temperatures between 20 and 40°C.
Acidophiles prefer environments with a pH of 3 to 4.
Halophiles grow optimally in high salt concentrations, between 5% to 15% NaCl.
Neutrophiles grow best at a pH of 7, typical of many pathogens.

Media and Inhibition

Mannitol salt agar is both selective and differential for specific microorganisms.
Antibiotic sensitivity testing, such as with Bacitracin on A disks, identifies susceptibility or resistance of bacteria.

Antiseptics and Disinfectants

Isopropanol acts as an antiseptic when used on skin.
Roccal is identified as a surfactant compound effective in microbe control.

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Description

Test your knowledge on microbiology lab safety protocols and equipment with this quiz. Questions cover biosafety levels, hazards, and fire safety measures specific to the lab environment. Perfect for students and professionals looking to enhance their safety awareness in microbiology labs.