microbiology lab

b. Wash both hands with water and soap

What should you do after working with biological specimens, chemicals, and lab substances?

a.Non of the above

b. Wash both hands with water and soap

c. Wipe both hands with a towel

d. Treat both hands with skin lotion

a. water

When an acid comes in contact with your skin, you should immediately wash it with what?

a. water

b. oil

c. soap

d. all of the above

A. Avoid wearing contact lenses in the lab, particularly when dealing with chemicals

Which of the following is a true statement?

A. Avoid wearing contact lenses in the lab, particularly when dealing with chemicals

b. Dangling and dazzling jewelry is acceptable in the lab

d. All of the above are true

b. Earphones can be worn as long as you are careful

C. Closed-toed shoes

Which of the following is the best footwear to use in the lab?

B. Sandals

C. Closed-toed shoes

A. Open-toed shoes

B. Away from you and other people

Where should test tubes be facing when you are heating them?

B. Away from you and other people

A. Towards the floor

C. Towards other people

A. To prevent glassware, heat, or chemicals from coming in contact with your eyes

What is the main purpose of wearing goggles and other eye protection devices?

C. To improve vision

A. To prevent glassware, heat, or chemicals from coming in contact with your eyes

B. To reduce eye strain

C. Toxic volatiles

Wearing a fume hood in the lab can help protect you from which of the following factors?

A. Viruses

C. Toxic volatiles

B. Bacteria

A. To reduce the incidence of contamination from microbes traveling in the air.

What is the primary purpose of keeping doors and windows closed during the laboratory session?

C. To keep you all in the room.

A. To reduce the incidence of contamination from microbes traveling in the air.

B. To increase the incidence of contamination from microbes in the room.

C. At the beginning and end of lab.

When should lab bench tops be cleaned with disinfectant solution?

B. Only at the end.

A. Never, take a chance!

C. At the beginning and end of lab.

C. Wash hands with detergent and ethyl alcohol, tie back long hair, and were closed toed shoes while in the laboratory.

Which of the following regulations should be observed in order to avoid injury and infection?

B. Wear open toe shoes and drop acid on your feet just for fun!

A. Never wash hands and keep hair long.

C. Wash hands with detergent and ethyl alcohol, tie back long hair, and were closed toed shoes while in the laboratory.

a. Immediately cover the spill with paper towels, saturate with disinfectant, then let sit for 20 minutes.

If you happen to spill a bacterial culture on the floor during lab, which of the following statements describes the correct clean-up procedure?

a. Immediately cover the spill with paper towels, saturate with disinfectant, then let sit for 20 minutes.

b. Immediately cover the spill with paper towels, saturate with disinfectant, then walk away.

c. Immediately cover the spill with paper towels, saturate with water, then let sit for 20 minutes.

c. A technique that is free from contaminating organisms

It is very important that microbiology students must develop aseptic techniques in order to prepare pure cultures. which of the following statements properly defines aseptic technique?

a. A technique that is full of contaminating organisms

b. A way to make you get sick when you want to!

c. A technique that is free from contaminating organisms

a. Place the disinfected paper towels into a biohazard bag.

What should be done with a paper towel used to cover a spilled microorganism after it has been soaked with disinfectant?

a. Place the disinfected paper towels into a biohazard bag.

b. Place the disinfected paper towels into a trash can.

b. Wash your hands with antimicrobial- containing soap for atlas 20 seconds

What is the last thing you should do before leaving the lab?

a. Do nothing, take a risk, you have lived a good life!

b. Wash your hands with antimicrobial- containing soap for atlas 20 seconds

b. f

You Can Pick-up test tube cultures by grabbing the plastic cap of the tube,

a. t

b. f

d. ocular

The Part of the microscope that always re-magnifies the image 10 times is called

a. light source

b. condenser

c. specimen

d. ocular

b. objective lens

The Part of the microscope that always magnifies the image 100 times is called

a. light source

b. objective lens

c. ocular lens

d. condenser

b. fine adjustment knob

The Part of the microscope that helps to focus the image is called

a. light source

b. fine adjustment knob

c. specimen

d. objective lens

A) light source; condenser; specimen; objective lens; ocular lens

Which of the following correctly traces the path of light through the compound microscope?

A) light source; condenser; specimen; objective lens; ocular lens

B) condenser; light source; specimen; ocular lens; objective lens

C) light source; specimen; condenser; objective lens; ocular lens

D) condenser; light source; specimen; objective lens; ocular lens

d. Eyepiece

The magnifying power of the compound microscope is the product of the magnification of the objective lens and _____.

a. Body tube

b. Reflector

c. Arm

d. Eyepiece

c. Stage

_____ is the metallic platform that is fitted to the lower part of the arm with a hole in the center

a. Base

b. Drawer tube

c. Stage

d. Automatic Stop

b. Condenser

Light can be focused by adjusting the _____.

a. Base

b. Condenser

c. Stage

d. Automatic Stop

b. Arm and base

Which two parts are used to hold the microscope?

a. base

b. Arm and base

c. Arm

d. Ocular lenses

false

Resolution (also called Magnification) is the ability of the lenses to distinguish fine detail and structure.

True

False

false

if a microscope has a resolving power of 0.4 nm, it can distinguish two points if they are at least 0.4 mm apart

True

False

true

The refractive index is the measure of bending of a light ray when passing from one medium to another.

True

False

false

The immersion oil has the same refractive index as air, so the oil becomes part of the optics of the glass of the microscope.

True

False

false

compound light microscope is called compound because it depends on both light and oil

True

False

true

when light rays from an illuminator, (the light source), it passes through a condenser, which has lenses that direct the light rays through the specimen.

True

False

false

The total magnification of a specimen can be calculated by multiplying all of the objective lens magnifications

True

False

d. Prevent the crystal violet from leaving the cells.

The purpose of a mordant in the Gram stain is to

a.Make the bacterial cells larger.

b. Make the flagella invisible

c. Remove the simple stain.

d. Prevent the crystal violet from leaving the cells.

C) 2-3-1

Which of the following places the steps in the correct sequence?

1-Staining

2-Making a smear

3-Fixing

a. colorless

You are performing a Gram stain on gram-negative bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point?

a. colorless

b. brown

c. purple

d. red

c. purple

You are performing a Gram stain on gram-Positive bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point?

a. colorless

b. red

c. purple

d. both red and purple

a. differential staining

Gram Staining is an example of

a. differential staining

b. acid staining

c. simple staining

d. spore staining

b. Crystal Violet

Staining material of gram positive bacterium is

a. Safranine

b. Crystal Violet

c. Haematoxylin

d. Eosin

a. cell wall

The Gram stain differentiates between bacteria based on the composition of their

a. cell wall

b. Plasma membrane

c. arrangement of Flagella

d. Nucleus

b. Crystal Violet & Safranine

The most commonly used combination of stains in the Gram staining is

a. Methylene Blue & Malachite Green

b. Crystal Violet & Safranine

c. Safranine & Methylene Blue

d. Crystal violet & Carbol fuchsin

b. Crystal violet, Iodine solution, Alcohol, Safranine

The order of Dyes, Mordant & Decolorizer in Gram-staining procedure is

a. Not Mentioned here

b. Crystal violet, Iodine solution, Alcohol, Safranine

c. Decolorizes the cells

d. Allows the color

false

The purpose of fixation in smear preparation is to keep the cells from drying out during staining.

True

False

c. The primary for acid fast is carbolfuchsin dye and the counterstain is methylene blue.

What is the primary and counter stain for acid fast stain

a. The primary for acid fast is methylene blue and the counterstain is carbolfuchsin dye.

b. Both dyes can be used as primary stain

c. The primary for acid fast is carbolfuchsin dye and the counterstain is methylene blue.

d. Both dyes can be used as counterstain

d. is the waxy mycolic acid in the cell wall

....................................is the structure that is responsible for allowing certain species to be acid fast.

a. Plasma membrane Proteins

b. Peptidoglycan in the cell wall

c. is the waxy mycolic acid in the plasma membrane

d. is the waxy mycolic acid in the cell wall

false

Mycobacterium smegmatis is negative for acid fast stain

True

False

false

If my acid fast species came out blue, instead of fuchsia, then it means that the species I used didn't have a plasma membrane

True

False

true

Acid-fast organisms are characterized by wax-like, nearly impermeable cell walls; they contain mycolic acid and large amounts of fatty acids, waxes, and complex lipids

True

False

true

Acid-alcohol is the decolorizing agent in the acid-fast staining procedure. Acid-alcohol removes carbolfuchsin from non-acid-fast cells.

True

False

every box

Acid-Fast Staining Instructions: Choose all possible answers (This question has more than one answer)

1. Air dry and heat fix a thin film of microorganisms. ...

2. Flood the slide with Carbolfuchsin. ...

3. Flood slide with Acid Alcohol for 30 seconds. ...

4. Counterstain by flooding the slide with Methylene Blue for 30 seconds. ...

5. Dry the slide by putting it between the pages of a book of Bibulous paper.

d. All of the above

Objectives of endospore staining

a. To detect for the presence of an endospore.

b. To identify endospore producing bacteria

c. To differentiate between the vegetative forms and the endospore

d. All of the above

true

Endospore stain allows visualization of endospores, resistant dormant cells often formed by Bacillus and Clostridium

True

False

false

Endospore can be stained using Gram stain; appears as clear object

True

False

false

Endospore stain uses ice to facilitate uptake of the primary dye malachite green by endospore

True

False

true

Endospores are resistant to harsh environment, have impervious spore coat and resist staining by traditional methods

True

False

b. Malachite Green

Endospores Primary stain

a. Safranin

b. Malachite Green

c. Crystal violet

d. All of the above

true

Endospore Stain : Flood smear(heat fixed) with malachite green over a beaker of water on a hot plate. Steam will cause spore to accept stain.

True

False

false

The acid-fast stain is a special stain

True

False

pure culture.

All the bacterial cells that result from the replication of a single original bacterial organism are referred to as a

-mixed population.

-pure culture.

-lag culture.

-mutant culture.

agar

The solidifying agent used most successfully in bacterial nutrient media is

gelatin

peptone

agar

starch

binary fission.

Prokaryotic cells divide by a process known as

conjugation

mitosis

binary fusion.

binary fission.

streak-plate method.

The simplest technique for isolating bacteria in growth media is referred to as the

-streak-plate method.

-MPN method.

-bacterial growth method.

-None of the above

True

The pour plate method is a microbiological laboratory technique for isolating and counting the viable microorganisms present in a liquid sample, which is added along with or before molten agar medium prior to its solidification

True

False

True

A bacterial colony is what you call a group of bacteria derived from the same mother cell. This means that a single mother cell reproduces to make a group of genetically identical cells, and this group of cells form a mass, which is known as a bacterial colony.

True

False

b. a method of isolation in which a diluted microbial sample is deposited on an agar plate and spread uniformly across the surface with a glass rod.

The Spread plate technique is__________________________________.

a. a method of generating mixed cultures of microbes.

b. a method of isolation in which a diluted microbial sample is deposited on an agar plate and spread uniformly across the surface with a glass rod.

c. a method of isolation of microbes based on the microbial culture's solution densities.

d. a method of tearing apart a microbe.

false

I solation method: After incubation, count colonies on plates that have only between 260-350 colonies

True

False

True

if 45 colonies are on a plate of 1:1000 dilution, then the count is 45 × 1000 = 45,000 bacteria/ml in sample.

True

False

False

Pour plate Method Reduces number of cells with each series of streaks

True

False

False

Spread plate method is based on pouring melted nutrient agar over the sample found in a petri plate. After this the sample and agar are swirled together and then agar solidifies.

True

False

To reduce contamination

What is the goal of aseptic techniques

To reduce contamination

To prevent contamination

To allow contamination

all of the above

Non drafty areas

In what kind of area should you perform aseptic techniques

Note: A drafty room or building has currents of cold air blowing through it, usually because the windows and doors do not fit very well.

Drafty areas

Anywhere

Non drafty areas

At home

By flaming

How should you sterilize materials that will make contact with your experiment

Wash them in the sink

You don't need to sterilize materials that will make contact with your experiment

Wiping it down with a tissue

By flaming

Before you add a solution

When should you label test tubes and petri plates

Before you add a solution

After adding a solution

While you are adding a solution

None of the above

Upside down

How should agar plates be incubated

-Right side up

-Sideways

-Upside down

-All of the above

Separate and identify bacterial colonies

Streak plates are useful in microbiology to __________.

quantify the number of bacteria

measure turbidity

Separate and identify bacterial colonies

determine cell shape

dilution on a solid surface

In the streak-plate technique, the intent is to isolate bacteria by dilution in theory by __________.

dilution on a solid surface

separating cells within the solid surface

using a pipette

dilution in water blanks

allows study of a single species

A pure culture consists of which of the following-

-allows study of a single species

-similar Gram stain reactions

-one streak

-turbidity

All of the above

A pure culture can be maintained as stock culture

Often stored in refrigerator as agar slant

Cells can be frozen at −70 degrees Celsius for long-term storage

Can be freeze-dried

All of the above

All of the above

Agar.......

Few microbes can degrade

a polysaccharide extracted from marine algae

Not destroyed by high temperatures and can be sterilized

All of the above

f

Agar solidifies above 45 degrees Celsius

True

False

True

Growth in Petri dish has two-part covered container of glass or plastic allows air to enter, but excludes contaminants

True

False

F

Agar plate: This is agar medium in a tube that was held at a shallow angle as the medium solidified, creating a larger surface area

True

False

T

Agar plate is Petri dish with agar nutrient medium

True

False

True

Sub-culturing, also referred to as passaging cells, is the removal of the medium and transfer of cells from a previous culture into fresh growth medium, a procedure that enables the further propagation of the cell line or cell strain.

True

False

b- Selective for gram negative bacteria

MacConkey Agar is:

 

a- Selective for gram positive bacteria

 

b- Selective for gram negative bacteria

 

c- Bacteria that are able to grow here are always lactose fermenting

 

d- yellow zone indicate Mannitol fermenting bacteria

 

e- all of the above

e- all of the above

Blood agar:

 

a- Enriched media used for the purpose of cultivating of fastidious organisms

 

b- differential

 

c- permits demonstration of hemolytic properties of some microorganisms

 

d- beta hemolysis: lysis of red blood cells

 

e- all of the above

e- all of the above

Mannitol salt agar:

 

a- Selective

 

b- differential

 

c- bacterial growth indicates that the bacteria are salt tolerant

 

d- yellow zone indicate Mannitol fermenting bacteria

 

e- all of the above

a- is a valid means of identifying Staphylococcus aureus, (production of Coagulase)

Coagulase Test

 

a- is a valid means of identifying Staphylococcus aureus, (production of Coagulase)

 

b- gas formation is considered a positive result

 

c- clot formation is considered a negative result

 

d- none of the above

 

e- all of the above

 

d- all of the above

Novobiocin Disc Test

 

a- On Mueller-Hinton Agar

 

b- Is used to distinguish Staphylococcus epidermidis from Staphylococcus saprophyticus

 

c- is used to determine the sensitivity of an organism

 

d- all of the above

f

Eosin methylene blue (EMB, also known as "Levine's formulation") is a selective stain for Gram-positive bacteria.

 

True

 

False

t

Hektoen enteric agar (HEK, HE or HEA) is a selective and differential agar primarily used to recover Salmonella and Shigella from patient specimens

 

True

 

False

f

Eosin methylene blue  contains dyes that are toxic to Gram-negative bacteria

 

True

 

False

f

Hektoen enteric agar contains indicators of lactose fermentation and hydrogen sulfide production; as well as inhibitors to prevent the growth of Gram-negative bacteria

 

True

 

False

True

The genus staphylococcus is composed of pathogenic and nonpathogenic organisms
• The 3 major species are
Staphylococcus aureus : pathogenic
Staphylococcus epidermidis : avirulant
staphylococcus saprophyticus : avirulant

 

True

 

False

f

Alpha-hemolysin breaks down the red blood cells and hemoglobin completely. This leaves a clear zone around the bacterial growth

 

True

 

False

 

All of the above

Citrate Utilization Test

 

screens a bacterial isolate for the ability to utilize citrate as its carbon and energy source

 

A positive diagnostic test rests on the generation of alkaline by-products of citrate metabolism.

 

Media: Simmon’s Citrate Agar Slants.

 

All of the above

f

Urease test, tests is the ability of organisms to secrete the amylase enzyme, which catalyzes the conversion of urea to ammonia and carbon dioxide

 

True

 

False

 

All of the above

Urease Test

 

Helpful in the identification of Proteus vulgaris

 

Media: Urea broth

 

A positive test is indicated by a bright pink color

 

A positive test indicates that the organism is able to degrade urea

 

All of the above

 

True

For the Identification of enteric bacteria: The IMViC series of tests can be used (Indole, methyl red, VogesProskauer and citrate utilization test)

 

True

 

False

F

Voges-Proskauer Test
-Determine the capability of some organisms to produce acidic end products (such as acetylmethylcarbinol) from the organic acids that results from glucose fermentation

 

True

 

False

T

The Triple Sugar Iron (TSI) test is a microbiological test named for its ability to test a microorganism’s ability to ferment sugars and to produce hydrogen sulfide.

 

True

 

False

F

Phenol red glucose fermentation broth: carbohydrates that have been fermented with the production of
acidic wastes will cause the phenol red to turn red: positive

 

True

 

False

T

STARCH HYDROLYSIS TEST
• This test is used to identify bacteria that can hydrolyze starch (amylose and
amylopectin) using the enzymes a-amylase and oligo-1,6-glucosidase.

 

True

 

False