Microbiology Lab Exam 1 Flashcards by Alicia 1

Which objective lens requires oil to be applied?
40x
100x
4x
10x

100x

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Information on the hazards posed by a chemical used in the laboratory can consistently be found

by asking your instructor.
posted on the wall of the laboratory.
in the lab manual.
on the Safety Data Sheets (SDS).

on the Safety Data Sheets (SDS).

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What lens could get dirty with oil if you move the revolving nose piece in the wrong direction after viewing under oil immersion?
4x
40x
10x
100x

40x

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You are looking at a drop of pond water and in the field of view, you observe a moving unicellular organism with short hairlike structures surrounding the outside surface of the cell. You are most likely observing an example of a/an ___ _
plant
cyanobacteria
protozoan
algae

protozoan

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Microorganisms are found in nearly every environment and are said to be
omniscient.
omnipresent.
ubiquitous.
contaminated.

ubiquitous.

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Soap should be applied to _____ hands.
gloved
dry
wet
clean

wet

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When can you bring food and beverages into the lab?

You can bring food into the lab when the lab has been cleaned by custodial staff in advance.
You can never bring food into the lab, but a container of water is acceptable.
You can bring sealed food and beverages into the lab.
You are never allowed to do so.

You can bring food into the lab when the lab has been cleaned by custodial staff in advance.

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Slides, scalpels, razor blades, cover glasses, and capillary tubes are all classified as
electrical hazards.
hazardous chemicals.
infectious agents.
sharps.

sharps.

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After focusing on an object with the low power objective lens, you are trying to bring it into focus under the 40x objective lens, but the field of view is very dark. Which of the following may remedy this problem?
Adjust the fine adjustment knob.
Only use lower power magnification.
Increase the light intensity.
Add more immersion oil.

Increase the light intensity.

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When should the chemical fume hood be used?
when using hazardous chemicals
when working with infectious microorganisms
when working with bad-smelling bacterial cultures
when working with microorganisms requiring BSL-2 safety precautions

when using hazardous chemicals

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Which of the following should be done first in the event of a laboratory accident?
Call 911.
Notify the instructor.
Notify campus security.

Notify the instructor.

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If you transfer bacterial growth from a broth to an agar plate but nothing grows after incubation, what may have occurred?
The lid may have been left off the Petri dish for too long during the transfer.
The loop may have been too hot when making the transfer.
The mouth of the broth tube may not have been passed through the Bunsen burner flame.
Contaminants may have been introduced into the broth culture.

The loop may have been too hot when making the transfer.

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A disinfectant is used on your work surface:
All of these answer choices are correct.
before the beginning of laboratory procedures.
after all work is complete.
after any spill of live microorganisms.

All of these answer choices are correct.

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To protect your skin and clothing from hazards such as chemicals and infectious organisms, what should be worn at all times in the lab?
lab coat
goggles
hooded sweatshirt
apron

lab coat

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A substance used to support the growth of microbial life is referred to as a
inoculating loop.
culture medium.
water.
incubator.

culture medium.

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The lenses of a brightfield microscope are responsible for the __ of the object you are viewing.
media type
contrast
color
magnification

magnification

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Which of the following streak plate diagrams shows the correct pattern for a quadrant streak plate method?

Plate C
Plate A
Plate B

Plate C

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Identify the correct statement below.
You are allowed to eat on the lab bench as long as you sterilize it with ethanol first.
Food and beverages should never be consumed or brought into the lab.
It is alright to bring a beverage into the lab as long as it is kept closed.
You are not allowed to eat, but you can drink beverages in the lab.

Food and beverages should never be consumed or brought into the lab.

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Please choose the answer that best completes the blanks of this sentence in the correct order. The ____ plate method involves spreading an inoculum onto the surface of a plate in a pattern that results in isolated colonies in some areas of the plate after incubation, whereas the ____ plate method involves diluting an inoculum into several melted agar tubes and then adding their contents into plates for solidification and incubation.
spread; pour
pour; streak
streak; spread
streak; pour

streak; pour

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Using oil immersion is useful because
oil immersion does not require special clean up.
oil immersion can be used on all objectives.
oil immersion increases the magnification of the specimen.
oil immersion increases the resolving power of the specimen.

oil immersion increases the resolving power of the specimen.

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When should you wear closed toed shoes in the lab?
only when corrosive chemicals are being used
always
only when working with sharp objects
never

always

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The coarse adjustment knob on the microscope
locates the specimen.
All of the answer choices are correct.
locates the focus plane.
fine-tunes the focus.

locates the focus plane.

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The objective lenses of the compound light microscope are attached to the
body tube.
stage.
revolving nosepiece.
base.

revolving nosepiece.

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Where should the label be placed on Petri dishes?
whichever location is most convenient
on the lid
on the bottom
on the edge

on the bottom

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The ____ is an appropriate tool to use for inoculating microorganisms into the butt of an agar slant. inoculating loop spreader inoculating needle pipette

inoculating needle

In which circumstance is food and/or beverage allowed in the laboratory? if containers are covered if containers are sealed if containers are kept out of sight never

never

Laboratory instruments are sterilized prior to reuse by ____ _ gassing with ethylene oxide soaking in disinfectant autoclaving (steam autoclave) incineration

autoclaving (steam autoclave)

Why is 35-37 degrees Celsius a standard incubation temperature range for many lab exercises involving medically important bacteria? This range is close to human body temperature, a temperature preferred by many of these organisms. This range is cooler than room temperature, protecting the organisms from death. This range denatures the enzymes that make these organisms pathogenic. This range is energy-efficient.

This range is close to human body temperature, a temperature preferred by many of these organisms.

If leaving an objective lens over the stage when storing the microscope, which objective lens should be placed over the stage? low power 10X oil immersion 100X high power 40X scanning 4X

scanning 4X

The best source of information regarding the hazards posed by any chemical and specific handling instructions is the lab partner. Safety Data Sheet (SDS). GOOGLE. lab manual.

Safety Data Sheet (SDS).

How long should you scrub your hands with soap before rinsing? 10 seconds 20 seconds 5 seconds

20 seconds

Which of the following environments resulted in the least amount of microbial growth? sanitized fingers (B) doorknob (C) benchtop (A) air in laboratory (D)

doorknob (C)

What does the term motile mean? solid fixed movable magnification

movable

How is an inoculating loop or needle sterilized prior to use? soaking in 95% ethyl alcohol for several minutes and allowing to air dry exposure to UV radiation for 15 seconds dipping into a beaker of boiling water holding in the hottest part of the Bunsen burner flame until red-hot

holding in the hottest part of the Bunsen burner flame until red-hot

Select the letter that matches the person correctly holding the microscope. C B A

Which of the following techniques results in isolated colonies found only in some areas on the agar surface? Spot Plate Technique Streak Plate Technique Spread Plate Technique Pour Plate Technique

Streak Plate Technique

A pure culture contains one type of microorganism. two types of known microorganisms. a number of known organisms.

one type of microorganism.

The goal of _______ technique is to minimize the contamination of both original and newly inoculated cultures as well as to protect the laboratory worker from contamination. sterile antiseptic inoculation aseptic

aseptic

You take your plate out of the incubator, and you notice an unknown large fuzzy colony growing on the plate with mostly red smooth colonies. This would be an example of a mixed culture. contamination. a pure culture. asepsis.

contamination.

Which metric unit is most appropriate for expressing the size of plant and animal cells? micrometer meter centimeter nanometer

micrometer

Bacteria are---�� meaning that they are distributed everywhere. ubiquitous diffracted septate dimorphic

ubiquitous

Jackie went to the sink at the end of lab to wash her hands. After removing her watch and rings, she turned on the water, wet her hands, added soap and thoroughly rubbed and lathered her hands for 30 seconds, cleaning the backs of her hands, her fingernails, and between her fingers. She then turned off the water, and reached for the paper towels to dry her hands. Identify the correct statement below. Jackie should have applied the soap to dry hands, and then added the water for lathering. Jackie should not have removed her watch and rings prior to washing her hands. Jackie should have used paper towels to turn off the faucet. Jackie used the correct protocol for washing her hands.

Jackie should have used paper towels to turn off the faucet.

Which of the arrows is pointing to an isolated colony? Arrow B Arrow A Arrow C

Arrow B

Which of the following environments exhibited the highest amount of microbial contamination? doorknob (C) air in laboratory (D) benchtop (A) sanitized fingers (B)

benchtop (A)

How is air contamination prevented when an inoculating loop is used to introduce or remove organisms from an agar plate? The plate lid is flamed before incubation. The plate lid is kept closed or lifted only slightly when inoculating. The loop is flamed just before introduction of organisms onto the plate surface. The plate lid is flamed before insertion of the loop.

The plate lid is kept closed or lifted only slightly when inoculating.

The fine adjustment knob on the microscope locates the specimen. fine-tunes the focus. locates the focus plane. All of the answer choices are correct.

fine-tunes the focus.

To retrieve a sample from a culture tube with an inoculating loop, the cap of the tube is All of the answers are correct. removed and held in one's teeth. removed with the fingers of the loop hand and placed in the fingers of the tube hand. removed and held with the fingers of the loop hand. removed with the fingers of the loop hand and placed on the laboratory bench.

removed and held with the fingers of the loop hand.

A student thought she had inoculated this plate the prior day, but this is what was observed after incubation. What might have occurred in the transfer to this plate? The inoculating transfer tool was heated at an incorrect time, killing the inoculum before she streaked the plate. The student used aseptic technique. The bottom of the plate was not heated before transfer. The original culture tube was not incubated just before the transfer.

The inoculating transfer tool was heated at an incorrect time, killing the inoculum before she streaked the plate.

The mechanical stage upper knob causes the stage to move All of the answer choices are correct. up and down. back and forth. right and left.

back and forth.

What is the purpose of the slanted surface in an agar slant? to increase the surface area for observable growth to keep the temperature within the optimum range to maintain transparency of the medium to provide better exposure to oxygen

to increase the surface area for observable growth

Media in slants and Petri dishes is solidified by the addition of polypeptides. gelatin. agar. polyacrylamide

agar.

Which metric unit is most appropriate for expressing the size of bacterial cells? micrometer nanometer centimeter meter

micrometer

When preparing pure cultures, dilution is necessary for reducing the number of inoculated organisms so that isolated colonies can develop. providing a hypotonic environment to enhance bacterial growth. preparing the melted agar for pour plating. ensuring that the bacteria receive adequate nutrition during incubation.

reducing the number of inoculated organisms so that isolated colonies can develop.

Lab coats, gloves, face masks, and goggles are all examples of items supplied by your college or university. fashion items preferred by biology students. personal protective equipment.

personal protective equipment.

A change in what component of microscopy influences the apparent size of the objects being viewed? contrast light intensity magnification

magnification

What is the correct way to open an agar plate to either remove a sample or to inoculate? Open lid slightly on one side, in a clamshell fashion. Remove the lid completely and set it on the bench in an upright position. Remove the lid completely and set it on the bench upside down. Remove the lid completely, holding it in your hand, not setting it on the bench.

Open lid slightly on one side, in a clamshell fashion.

The ___ lenses further magnify the image produced by the objective lens. stage ocular condenser iris

ocular

In what type of emergency situation would you utilize the equipment seen in this image? Removing a large volume of chemicals spilled on unprotected arms or splashed onto your face or eyes. Extinguishing a fire on the lab bench. Inhalation of fumes of hazardous chemicals. Cleaning up a spill of infectious microorganisms.

Removing a large volume of chemicals spilled on unprotected arms or splashed onto your face or eyes.

When storing the microscope the stage should be left in the __ position. central middle fully down fully up

fully down

Which of the following approaches to the study of microorganisms enables direct viewing of microbial cells? microscopic microscopic macroscopic genetic

microscopic

Which of the following is defined as the ability to distinguish fine detail? contrast magnification media type resolution

resolution

When performing a Standard Plate Count (SPC), plates that contain ____ colonies are selected for counting with a colony counter. 10-100 colonies 50-100 colonies 100-500 colonies 30-300 colonies

30-300 colonies

The lens on the microscope that is primarily responsible for the magnification of the specimen is the _______ lens iris objective condenser ocular

objective

What advantage does the pour plate method have over the quadrant streak plate method? It requires less skill. It requires fewer materials. It only requires an inoculating tool and one plate. It provides isolated colonies.

It requires less skill.

Which is the most appropriate disposal for a swab used to culture your throat during lab? normal trash receptacle biohazard bag sharps container recycle bin

biohazard bag

Which of the following would be most appropriate for disposal of cultures on agar plates? biohazard bag or bin sharps container normal trash receptacle

biohazard bag or bin

Which term refers to the introduction of unwanted microorganisms? inoculation ubiquitous contamination sterilization

contamination

What term is used to describe the cloudiness produced by bacterial growth in a tube of broth? precipitation colonies particulation turbidity

turbidity

Which of the following must be visually studied using electron microscopy? viruses eukaryotes fungi prokaryotes

viruses

You have successfully focused on an object with the 10x and 40x objective lenses. You have rotated the 100x objective lens into position but are unable to obtain a sharp image by rotating the fine focus adjustment knob. Which of the following is most likely to correct this problem? Decrease the light intensity. Use the coarse focus adjustment knob to sharpen the image. Add a drop of immersion oil before rotating the 100x lens into position.

Add a drop of immersion oil before rotating the 100x lens into position.

Why is the mouth of a culture tube passed through the Bunsen burner flame after removing and before replacing the cap? to sterilize the glass rim of the tube to make sure the cap will be easily replaced onto the tube to prevent the entry of ambient air, which might introduce contaminants

to prevent the entry of ambient air, which might introduce contaminants

You have a nutrient broth, an agar slant, and an agar plate with bacterial growth in or on each. If you wanted to evaluate the macroscopic appearance of the bacteria growing in or on the medium, which of the cultures would be the best choice? broth agar plate agar slant

agar plate

An inoculating loop or needle is sterilized in a flame or incinerator until the tip is bright red. by one brief passage. until the entire wire is bright red. until the handle is bright red. for exactly five minutes.

until the entire wire is bright red.

Staining cells such that their color is different from the background enhances their contrast. resolution. media type. magnification.

contrast.

Which of the following results in isolated colonies within the agar and on top of the agar? spread plate method pour plate method streak plate method

pour plate method

Where should glass slides, pipettes, and capillary tubes be disposed? biohazard bag regular trash container sharps container recyclable trash container

sharps container

Which objective lens provides the least total magnification? scanning oil immersion low power high power

scanning

What type of medium provides the best opportunity for growing and observing the morphology of isolated colonies? broth slants agar plates

agar plates

Which of the following is the process of making an object appear larger? resolution media type contrast magnification

magnification

The very first and last step to every microbiology lab exercise is to remove or add materials to the incubator. to disinfect the lab bench. to create a new stock culture to preserve organisms. to label and recheck the labels on your cultures.

to disinfect the lab bench.

During which of the following lab activities is it most important to tie back long hair and secure loose clothing ? heating a beaker of water on a hot plate conducting an aseptic transfer of bacteria using the Bunsen burner testing glucose and protein levels in a urine sample observing histology slides in the light microscope

conducting an aseptic transfer of bacteria using the Bunsen burner

The mechanical stage lower knob causes the stage to move right and left. All of the answer choices are correct. up and down. back and forth.

right and left.

The _____ causes the stage to move upward or downward. mechanical stage objective lens iris diaphragm coarse adjustment knob

coarse adjustment knob

The purpose of lab safety rules and protocols is to protect everyone in the lab from injury and infection. ensure that the lab activities always produce the expected results. enable students to complete lab assignments and activities in less time. ensure that the lab stays clean and orderly.

protect everyone in the lab from injury and infection.

When should you wear a lab coat in the laboratory? You only need to wear a lab coat when working with dangerous chemicals and organisms. You do not need to wear a lab coat when you already have long sleeves. You should always wear a lab coat. You only need to wear a lab coat when working with colored chemicals.

You should always wear a lab coat.

During the steps of the streak plate method, the bacterial culture is only added to the plate ___ _ time(s). 4 2 3 1

Which of these tubes shows the results of a correct slant to slant transfer? SlantA Slant B

SlantA

If your inoculated slant shows no growth after incubation, what may have occurred during bacterial transfer? You sampled the bacteria while the loop was still too hot. You forgot to flame the loop before adding the bacteria to the slant surface. You did not sample from an entire bacterial colony.

You sampled the bacteria while the loop was still too hot.

Which objective lens provides the highest total magnification? scanning low power high power oil immersion

oil immersion

When incubating a plate, it should be placed in the incubator with the __ _ lid removed lid side down lid side up

lid side down

Jacob had just finished his lab work and went to the sink to wash his hands. He removed his watch, and added liquid soap to his hands. He then turned on the water and began to rub his hands together, lathering for 20 seconds and cleaning fronts and backs of hands, fingernails, and between his fingers. He then rinsed his hands in running water, dried his hands with paper towels, and used an additional paper towel to turn off the faucet. Which statement is correct? Jacob wasted paper towels by using one to turn off the faucet. Jacob should have washed his hands for at least a minute. Jacob did everything correctly. Jacob should have wet his hands in running water before applying the soap.

Jacob should have wet his hands in running water before applying the soap.

The magnification of the ocular lens is 10x 40x 4x 100x

10x

What is contamination? The transfer of mixed species from one medium to another The introduction of an unwanted organism into a culture The introduction of a known organism into a culture

The introduction of an unwanted organism into a culture

What biosafety levels do most introductory microbiology students work with? BSL-3 All of the answer choices are correct. BSL-2 BSL-1

BSL-1

Which of the following must be visually studied using microscopy? fungi prokaryotes eukaryotes plants

prokaryotes