Final

Question 1

________ acid is an end product of the bacterial action that contributes to yogurt’s taste and thick consistency.

a. Hydrochloric
b. Lactic
c. Sulfuric
d. None of the above

Answer 1

B

Question 2

(T/F) Hypotonic conditions occur when the concentration of “free water” is lower outside the cell than inside.

Answer 2

F

Question 3

Organisms that grow at high pH are called

a. Xerophiles
b. Osmophiles
c. Alkaliphiles
d. Acidophiles

Answer 3

C

Question 4

The control quadrants of the salt plates are left uninoculated to check the ____ of the medium.

a. Sterility
b. pH
c. Viability
d. Pressure

Answer 4

A

Question 5

(T/F) It is important that you flame and cool the loop between each transfer so that no acid or base is transferred back into the culture from the medium.

Answer 5

T

Question 6

For the osmotic pressure and pH lab, you will incubate the tubes at

a. 37◦C for 48 hrs
b. 30◦C for 24 hrs
c. 37◦C For 24 hrs
d. 30◦C for 48 hrs

Answer 6

D

Question 7

Yogurt is a thick sour milk product produced by the action of Streptococcus thermophiles and Lactobacillus bulgaricus on the sugar ______ in milk.

a. Glucose
b. Fructose
c. Lactose
d. Sucrose

Answer 7

C

Question 8

Organisms that can tolerate and grow in the presence of high concentration of sdium chloride are referred to as:

a. Osmotolerant
b. Xerotolerant
c. Hypertolerant
d. Halotolerant

Answer 8

D

Question 9

(T/F) Cyanobacteria, algae, and protozoa are all alkaliphiles.

Answer 9

T

Question 10

Fermented milk products are prepared from milk that has undergone a controlled ______ that results in acceptable tastes.

a. Refrigeration
b. Fermentation
c. Condensation
d. Inoculation

Answer 10

B

Question 11

Which of the following microorganism where used to make our yogurt?

a. Bacillus subtilis
b. Enterobacter aerogenes
c. Streptococcus pneumoniae
d. Lactobacillus bulgaricus

Answer 11

D

Question 12

We are evaluating yogurt by:

a. Observing and documenting the pH of the mixture.
b. Serial dilution, spread plating, and counting the viable organisms in the yogurt.
c. Streak plating for isolation the different organisms in the mixture.
d. Determining absorbency using the light spectrometer to determine CFUs of the original yogurt.

Answer 12

B

Question 13

After plating the diluted yogurt, we will:

a. Incubate the plates at 30°C for 24 hours.
b. Refrigerate the plates to prevent spoilage.
c. Light a candle with the plates in a sealed jar prior to incubating at 37°C for 48hrs.
d. Incubate the plates at 37°C for 24hours.

Answer 13

C

Question 14

The original organisms that grew in the yogurt came from:

a. A culture we grew in the previous lab.
b. A spoonful of plain yogurt purchased from the grocery store.
c. Yeast that is used to ferment barley into beer.
d. A packet of organisms purchased off the internet.

Answer 14

B

Question 15

(T / F) You are going to taste the yogurt.

Answer 15

T

Question 16

What is gDNA?

a. Gene DNA
b. Genomic DNA
c. Genre DNA
d. None of the above

Answer 16

B

Question 17

( T / F ) PCR stands for Polymerase Chain Reaction.

Answer 17

T

Question 18

What are the steps of PCR?

a. Dissolving, annealing, and elongation
b. Denaturing, adding, and elongation
c. Denaturing, annealing, and extension
d. Dissolving, adding, and extension.

Answer 18

C

Question 19

The typical yield from PCR is:

a. 1 million to 1 trillion copies
b. 10,000 to 1 million copies
c. 1 billion to 100 billion copies
d. 1 hundred to 10,000 copies

Answer 19

A

Question 20

What DNA stain will be added to the agarose gel that is used in the electrophoresis procedure?

a. Methyl blue
b. Safranin
c. Ethidium Bromide
d. Iodine

Answer 20

C

Question 21

At what wavelength is the absorbance used to determine the DNA concentration?

a. 230 nm
b. 245 nm
c. 360 nm
d. 260 nm

Answer 21

D

Question 22

( T / F ) DNA is visualized after electrophoresis using regular-visible light.

Answer 22

F

Question 23

What area did the Taq (theDNApolymeraseusedforPCR) come from?

a. Antarctica
b. A hot spring
c. Bottom of a lake
d. Soil

Answer 23

B

Question 24

Which of these activities below are okay to do in lab?

a. Mouth pipet
b. Apply makeup
c. Drink & eat
d. Wear opened toe shoes
e. None of the above

Answer 24

E

Question 25

When do you need to wear safety glasses? a. Working with flames b. Writing in your lab book c. Working with liquids d. Both a & c

Answer 25

D

Question 26

(T/F): Candida albicans is a prokaryote that causes Thrush.

Answer 26

F

Question 27

We don’t immediately dry the bleach off of our workspaces because: a. Too save paper towels b. The bleach needs to inactivated before wiping up c. Contact time is required to sterilize the surfaces d. Bleach is only effective when exposed to the atmosphere

Answer 27

B

Question 28

E. coli is found in: a. Soil b. Your eyes c. Feathers d. GI tracts

Answer 28

D

Question 29

TSA stands for: a. Tryptic soy agar b. Typical substances agar c. Trending standard agar d. T. serratia agar

Answer 29

A

Question 30

Staphylococcus aureus is a prokaryote that causes: a. Thrush b. Toxic shock syndrome c. Cancer d. Food poisoning e. Both b & d

Answer 30

E

Question 31

When inoculating test tubes, the test tube lid is: a. Set on the counter b. Held in your hand, not touching the edges c. On it’s side on a kimwipe d. Held in your partner’s hand

Answer 31

B

Question 32

A colony of a pure culture is a. a visible aggregate of the progeny of one cell b. A mixture of microbes c. Used to help identify an organism d. Both a & c

Answer 32

D

Question 33

Indicate below whether it’s a prokaryote (P) or eukaryote (E) feature (each is worth 1 point): a. _ Includes animals, plants, fungi/yeast b. _ No nuclear membrane c. _ Includes bacteria d. _ About 10μm or bigger e. _ Nuclear membrane f. _ Usually about 1μm or smaller

Answer 33

``` E P P E E P ```

Question 34

Which of the below is a properly formatted scientific name: a. Escherichia coli b. Escherichia Coli c. escherichia Coli d. Escherichia coli

Answer 34

D

Question 35

(T/F): Report all accidents, no matter how small, to your teaching assistant, immediately.

Answer 35

T

Question 36

(T/F): When there is liquid in the loop you need to quickly evaporate the liquid off before putting the loop into the flame to prevent aerosol formation.

Answer 36

T

Question 37

(T/F): Kimwipes should be used to remove oil from the 100x objective.

Answer 37

F

Question 38

TSA stands for... a. Tryptic soy agar b. Typical substances agar c. Trending standard agar d. T. serratia agar

Answer 38

A

Question 39

A ______ broth culture probably has bacterial growth in it. a. Clear b. Transparent c. Turbid d. Yellow

Answer 39

C

Question 40

We work with cultures near a flame to... a. Sterilize the surrounding air. b. Generate positive pressure around our cultures. c. Provide light for visualizing cultures. d. Dehydrate aerosols.

Answer 40

B

Question 41

Nosocomial infections are: a. Nasal diseases b. Hospital acquired c. Coma inducing d. Soil derived

Answer 41

B

Question 42

Where are the fire extinguishers located? a. By the incubator b. By the autoclave cart c. By each door d. The end of your bench

Answer 42

C

Question 43

Why are open culture tubes held in a horizontal position? a. To keep microbes in container b. To prevent contamination from particles falling in the tube c. To allow particles to come in d. You don’t hold open culture tubes in a horizontal position.

Answer 43

B

Question 44

Our microscopes have 10X ocular lens, so at what objective do you need to use to get a total magnification of 400X? a. 4X objective b. 20X objective c. 2X objective d. 40X objective

Answer 44

D

Question 45

_____ is a laboratory practice that minimizes contamination. a. Septic technique b. Aseptic technique c. Pure culture technique d. Isolation technique

Answer 45

B

Question 46

What paper should you use to remove the oil from the objective lens on the microscope? a. Sand paper b. Kim-wipes c. Paper towels d. Lens paper

Answer 46

D

Question 47

S. marcescens is a bacteria that causes: a. Urinary infections b. Food poisoning c. Septicemia d. Both a & c

Answer 47

D

Question 48

(T/F): Immersion oil is used to protect the 100X objective lens from being scratched.

Answer 48

F

Question 49

Why do we flame the test tube when transferring cultures? a. To kill off the bacteria b. To heat up the sample c. To create positive pressure and prevent contamination d. All of the above

Answer 49

C

Question 50

How do you carry your microscope? a. Like a football, under your arm. b. With your partner, holding one side each c. With one gripping the handle d. With two hands, one holding the base and the other holding the grip

Answer 50

D

Question 51

Broken glass is put in: a. Biohazard bag b. Regular trash c. Sharps containers d. None of the above

Answer 51

C

Question 52

Plates are inverted: a. To prevent condensation on the agar b. To prevent growth on the lid c. So the plates stack nicely in the incubator d. For no reason at all

Answer 52

A

Question 53

(T/F): BAP stands for blood agar plate.

Answer 53

T

Question 54

Microbes can be found in: a. Clothes b. Hot Springs c. Doorknobs d. Water e. All of the above

Answer 54

E

Question 55

(T/F): It is not possible to identify a species based on colony morphology alone.

Answer 55

T

Question 56

(T/F): Ubiquitous means microorganisms are found virtually everywhere.

Answer 56

T

Question 57

(T/F): S. marcescens is a gram-negative rod found in the environment and GI tract of rodents and insects.

Answer 57

T

Question 58

(T/F): B. subtilis is a gram-positive rod that is a spore forming bacteria found in the soil.

Answer 58

T

Question 59

Our microscopes are parfocal which means: a. The lens stays in focus when the objectives/magnification are changed. b. Have multiple objectives c. Have a y-axis knob and an x-axis knob d. None of the above

Answer 59

A

Question 60

(T/F): Once you sterilize your inoculating loop, you can set it down on the lab bench without re-contaminating it.

Answer 60

F

Question 61

The term microbiota refers to: a. A disease acquired in a hospital b. The concentration and distribution of microorganisms c. The microorganisms that cover your body d. A type of plate used for inoculation

Answer 61

C

Question 62

(T/F): Streak Dilution is done to obtain isolated colonies.

Answer 62

T

Question 63

An individual cell, well separated from its neighbors on an agar surface, will give rise to a/an a. ) Mixed culture b. ) Isolated colony c. ) Normal Flora d. ) None of the above

Answer 63

B

Question 64

The skin, mucosal surfaces, and the intestines of the human body support large numbers of microorganisms that comprise the a. ) Genome b. ) Pure culture c. ) Microbiota d. ) Mixed culture

Answer 64

C

Question 65

(T/F): TSA stands for Telluric Soy Agar.

Answer 65

F

Question 66

A Bacterial colony is a. ) A visible mass of cells b. ) A single bacteria c. ) A type of media d. ) None of the above

Answer 66

A

Question 67

(T/F) You should be worried about the large number of organisms that were found in your mouth.

Answer 67

F

Question 68

The purpose of streaking for isolation is a. ) Get a layer of growing cells to cover the full surface of the plate b. ) Make a mixed culture c. ) Obtain isolated cells d. ) Determine the number of colony forming units

Answer 68

C

Question 69

(T/F) Disinfection is a sterilization method.

Answer 69

F

Question 70

(T/F) It is not necessary to wear safety glasses when working with liquids and flames.

Answer 70

F

Question 71

Normal mouth flora includes a. ) Neisseria b. ) Streptococci c. ) Fungi d. ) All of the above

Answer 71

D

Question 72

Most bacteria have a rigid cell wall of ________ that is responsible for maintaining the bacterial shape under a variety of osmotic conditions. a. ) ribonucleic acid b. ) peptidoglycan c. ) anions d. ) aniline

Answer 72

B

Question 73

Label below the correct order of the gram staining process. This question is worth 4 points. a. ) Iodine b. ) Alcohol c. ) Crystal violet d. ) Safranin

Answer 73

2 3 1 4

Question 74

(T/F): Gram-negative cells have a thin peptidoglycan layer that, upon exposure to alcohol, is not thick enough to retain the crystal violet-iodine complex.

Answer 74

T

Question 75

During a Gram stain, what causes the Crystal violet to stay inside the cell wall? a. ) The negative change of the ribosomes in the cell wall. b. ) The positive charge of the ribosomes in the cell wall. c. ) Its complex with iodine is too large to escape the thick peptidoglycan cell wall. d. ) Crystal violet is not made to stay inside the cell wall. That is why you must be cautious when decolonizing.

Answer 75

C

Question 76

When visualizing a microorganism after Gram stain, you will be able to differentiate Gram- positives, which are ___________, from Gram-negatives, which are ____________. a. ) Pink(Red), Purple(Blue) b. ) Purple(Blue), Pink(Red) c. ) Pink(Red) with purple centers, purple(blue) with pink centers d. ) Purple(Blue), Green

Answer 76

B

Question 77

What is the advantage of the Gram stain over simple stain? a.) A simple stain just accents (colors) microorganisms, whereas a Gram stain will differentiate microorganisms. b.) Simple stains utilize anions and Gram stains utilize cations. c.) Simple stains will bind well with the thick peptidoglycan to identify Gram-negative prokaryotes d.) There is no difference between simple stains and Gram stains

Answer 77

A

Question 78

If you examined a Gram stained sample at 1000x in a microscope and saw that all the cells’ morphology (shape) are the same, but you are seeing both purple(blue) and pink(red) stained cells, you may have: a. ) Decolorized for too long a time b. ) Decolorized for too short a time c. ) Have a mix of Gram-positive and Gram-negative cells d.) Any of the above

Answer 78

D

Question 79

(T/F): Bacterial cells contain an abundance of positively charged ribonucleic acid in their ribosomes.

Answer 79

F

Question 80

Which dilution had the lowest absorption/optical density recording on the spectrophotometer? a) Undiluted b) 1:2 c) 1:4 d) 1:8 e) 1:16

Answer 80

E

Question 81

Why is the safranin counterstain used? a. ) To “lock in” the crystal violet into the Gram-negative cell wall. b. ) To prevent over-decolonization. c. ) To stain the Gram-negative cells after the decolorization step. d. ) To initially stain the Gram-positive cells as a first step.

Answer 81

C

Question 82

(T/F) Optical density is also known as absorption.

Answer 82

T

Question 83

When we used the spectrophotometer, a blank was used to calibrate the machine. What did we use as a blank? a. ) Water b. ) An empty spectrometer tube c. ) An undiluted sample d. ) Sterile media

Answer 83

D

Question 84

(T/F) CFU stands for colony factoring units.

Answer 84

F

Question 85

The range of colonies on a plate for a viable cell count is: a.) 5 to 25 b. ) 25 to 250 c. ) 1000 to 1500 d. ) 250 to 350

Answer 85

B

Question 86

To find the viable cells per milliliter (CFU/ml) we use: a. ) (average colony count) (1/dilution factor) b. ) (1/average cell count)(dilution factor) c. ) (average cell count) (dilution factor) d. ) None of the above

Answer 86

C

Question 87

(T/F) The two most common techniques used to determine cell counts are viable cell count and optical density.

Answer 87

T

Question 88

What temperature does the agar solidify at? a. ) 100°C b. ) 45°C c. ) 15°C d. ) 0°C

Answer 88

B

Question 89

Why would a viable cell count vary from the number of colony forming units? a. ) Dead cells b. ) Overgrowth c. ) Cells stuck to one another d. ) A and C

Answer 89

C

Question 90

We used Optical Density to measure the concentration of cells. What was the wavelength used? a. ) 450 nm b. ) 375 nm c. ) 600 nm d. ) 260 nm

Answer 90

C

Question 91

(T/F): The word ‘sterile’ means that no living organisms are present.

Answer 91

T

Question 92

(T/F): The fast(gravity) cycle can be used for liquids.

Answer 92

F

Question 93

What are the standard conditions for sterilization in an autoclave? a. ) 121°F for 60 minutes b. ) 100°F for 15 minutes c. ) 121°C for 15 minutes d. ) 100°C for 60 minutes

Answer 93

C

Question 94

Heat kills microorganisms: a. ) By burning them up b. ) By coagulating proteins c. ) A & B d. ) Heat can kill microorganisms because of endospores.

Answer 94

B

Question 95

(T/F): Moist heat penetrates more effectively than dry heat.

Answer 95

T

Question 96

Match whether the below chemicals are antiseptic (A) or disinfectant (D). This question is worth 7 points. a. ) Mouthwash b. ) 100% ethanol c. ) Betadine d. ) Lysol e. ) Hydrogen peroxide f. ) 5% bleach g. ) 70% ethanol

Answer 96

``` A A A D A D A ```

Question 97

Mannitol salt agar (MSA): a. ) Is selective for Staphylococcus b. ) Inhibit the growth of many Gram-negative organisms c. ) Is differential for mannitol fermenters d. ) All of the above

Answer 97

D

Question 98

Violet red bile agar (VRB): a. ) Is a selective media b. ) Is a differential media c. ) A & B d. ) None of the above

Answer 98

C

Question 99

(T/F): Plate count agar (PCA) is both a selective and differential media.

Answer 99

F

Question 100

Which of the factors below can affect the ability of a particular chemical to kill a particular pathogen? a. ) Time b. ) Temperature c. ) pH d. ) All of the above

Answer 100

D

Question 101

(T/F): Our microbiota is an important mechanism for limiting pathogenic microorganisms on our bodies.

Answer 101

T

Question 102

To test whether the autoclaving was successful in sterilizing material, we place an envelope of _____ in with a load that is being autoclaved. a. ) A plate of very concentrated Bacillus stearothermophilus cells b. ) Bacillus stearothermophilus vegetative (growing) cells c. ) Bacillus stearothermophilus toxins d. ) Bacillus stearothermophilus endospores

Answer 102

D

Question 103

Coliforms a. ) Are Gram-positive b. ) Are facultative anaerobic rod-shaped bacteria c. ) Will appear as deep purple colonies on a VRB media d.) B & C

Answer 103

D

Question 104

(T/F): A chemical used on a living object, such as tissue of a human body, for disinfection is called a antiseptic.

Answer 104

T

Question 105

(T/F): Autoclaves routinely sterilize medium, and biohazardous garbage under 15-23 psi (pounds per square inch).

Answer 105

T

Question 106

(T/F): Dry heat ovens do not need longer times or longer temperatures to achieve sterilization.

Answer 106

F

Question 107

(T/F): Members of the genus Bacillus are capable of forming endospores.

Answer 107

T

Question 108

Which section of lab do you belong in? This question is worth one point. a. ) 01 b. ) 02 c. ) 03 d. ) 04 e. ) 05

Answer 108

E