Lab 1 & Lab 2A- Study Quiz

Question 1

Adjust the ocular lenses distance to accommodate your individual ____ _____.

Answer 1

interpupillary distance

Question 2

After ______ (last step), as a result of this dilution technique, individual colonies of microbes can be obtained.

Answer 2

incubation

Question 3

As the magnification of the objective lens increases, so does the _____ ______.

Answer 3

numerical aperture

Question 4

Endospores are most commonly found in …

Answer 4

Bacillus sp. & Clostridium sp

low G+ C Gram positive bacteria

Question 5

2 correct responses:

In acid fast bacterial staining procedures…..

Answer 5

=It depends on mycolic acid (It reinforces the cell wall and makes the bacterium resistant to certain chemicals and dyes)
=The Kinyoun stain can be used to stain Nocardia species and Crytosporidia

Question 6

culture/ cultured means

Answer 6

grown / growing

Question 7

Each individual colony represents the descendants of a ___ ___.

Answer 7

Single Cell

Question 8

How do you find the magnification?

Answer 8

Ocular lens X objective lens

Question 9

How do you refocus the new image after changing to higher magnification?

Answer 9

Use the fine adjustment knob

Question 10

If you are determining a bacteria morphology, what are you going to focus on?

Answer 10

shape, size, & arrangement

Question 11

If your CONTROL test tube is CLOUDY, what does this mean?

Answer 11

You did not correctly use the aseptic techniques. It should remain clear. It is the controlled tube, so it shouldn’t grow anything.

Question 12

In numerical aperture (n* sin a), (sin a) is ___ of the ___ ___ of the image forming rays of the objective lens.

Answer 12

1/2, acceptance angle

Question 13

In numerical aperture (n * sin a), the (n) is ?

Answer 13

The refractive index or index of refraction

Question 14

Refractive index

Answer 14

measure of the bending/ “refraction” of a ray of light when passing from one medium into another.

Question 15

In the Gram Stain, Iodine is used as the____?

Answer 15

Mordant

Question 16

Mordant

Answer 16

Substance used to set or stabilize stains or dyes.

Example: Iodine acts like a trapping agent that complexes with the crystal violet, make the crystal violet-iodine complex clump and stay contained in thick layers of peptidoglycan in cell walls.

Question 17

List the basics of aseptic techniques that are used in lab…

Answer 17

Autoclave or steam sterilization of all equipment and media.

Flame sterilization of wire loops and needles which are used to transfer bacteria from one growth condition to another.

Flaming the mouth of test tubes and other containers to establish hot air convection out of the container, to reduce the chance of microbes entering the tube by air flow.

Question 18

Numerical Aperture

Answer 18

Related to the angles of light which are collected by lens.
—> NA= “n sin a” where (n )is the refractive index and (a) is half the acceptance angle of the image forming rays of the objective lens.

Question 19

Resolution is dependent on the _A__ of light used (in um),

the _B__ quality, and the refraction and _C__ of light as it passes through the object and air

Answer 19

A. wavelength
B. lens
C. reflection

Question 20

The Bunsen burner should be adjusted so that you can see __A_ flames.

The dark blue flame is in the __B_ of the flame.
The light blue flame is at the __C_ of the flame.

Answer 20

A. 2
B. center
C. top

Question 21

The direction of stage movement is ______ to that of the field movement.

Answer 21

Opposite

Question 22

The standard method of obtaining a “PURE CULTURE” is the

___ ____ method on agar.

Answer 22

Streak-plate

Question 23

The ____ is below the stage on a microscope.

Answer 23

Condenser

Question 24

True or False: The resolution of a light microscope is the smallest distance between two adjacent points capable of being distinguished on a slide.

Answer 24

True

Question 25

Inoculated

Answer 25

introduced

Question 26

How many objective lens are on the microscope in our lab? | List their magnification

Answer 26

``` 4 objective lens 4x=40x 10x=100x 40x=400x 100x=1000x ```

Question 27

Pathology of bacteria means...

Answer 27

ability to cause disease

Question 28

What is the purpose of the CONDENSER

Answer 28

Focus light onto the specimen

Question 29

What is a "PURE CULTURE"?

Answer 29

Uncontaminated culture

Question 30

What is differential stain procedure?

Answer 30

stain procedure consists of at least two different dyes which highlight a biochemical reaction within the cell. It shows more than just simple cell structures.

Question 31

What is resolution?

Answer 31

the smallest distance two closely adjacent objects can be clearly distinguished with the lens system that is set up

Question 32

What are the two properties that determine image quality?

Answer 32

Magnification / Resolution

Question 33

What is simple stain procedure?

Answer 33

consists of only one dye to increase cell contrast from a slide background. It shows simple cell structure.

Question 34

What is the process of growing pure cultures and is essential for proper characterization of a bacterium?

Answer 34

aseptic (sterile) technique

Question 35

_______ has to be performed without adding other microbes or contaminates.

Answer 35

inoculation

Question 36

What is the formula used to calculate resolution? What does (λ) mean? What does NA stand for?

Answer 36

Resolution = λ / (2xNA) where λ = wavelength of light in μm (microns) NA = numerical aperture (+0)

Question 37

Where is the numerical aperture found?

Answer 37

Numerical aperture is etched onto the objective lens next to that lens' magnification.

Question 38

The smallest resolution of the light microscope can be obtained with:

Answer 38

The shortest wavelength of visible light used and an objective lens with the maximum numerical aperture

Question 39

What is the total magnification of a slide field if you are visualizing that field with the 40X objective lens?

Answer 39

400X magnification.

Question 40

How do you find total magnification?

Answer 40

ocular lens (10x) X objective lens (4x, 10x,40x,100x)

Question 41

What is the correct order of reagent use when performing a Gram stain?

Answer 41

crystal violet, iodine solution, acetone alcohol, safranin

Question 42

Basic stains have a positively charge auxochrome? T or F

Answer 42

TRUE

Question 43

Negative stains are attracted to glass. T or F

Answer 43

True

Question 44

Positive stains are attracted to cell contents. T or F

Answer 44

True

Question 45

Nigrosin is a basic stain. T or F

Answer 45

False- It is an acidic stain

Question 46

Methylene blue is a basic stain. T or F

Answer 46

True

Question 47

What color will a gram negative organism be if the decolorizing step is left out while performing a gram stain on it?

Answer 47

Purple

Question 48

Choose the INCORRECT response: A. is a virulence factor B. its size is not determined by its growth medium C. can be composed of polysaccharides or polypeptides D. is genetically determined

Answer 48

B. its size is not determined by its growth medium

Question 49

In Acid Fast Bacterial staining procedures: The Kinyoun stain can be used to stain _______ and ______.

Answer 49

Nocardia species and Cryptosporidia

Question 50

Acid Fast Bacterial staining procedures depend on______?

Answer 50

depends on mycolic acid

Question 51

T or F: There are several species of Mycobacterium that are of human clinical significance. The species that is most significant is Mycobacterium leprae.

Answer 51

False- Mycobacterium tuberculosis is a species of pathogenic bacteria that is the causative agent of tuberculosis. First discovered by Robert Koch, M. tuberculosis has an unusual, waxy coating on its cell surface primarily due to the presence of mycolic acid

Question 52

# Choose the CORRECT response(s): Endospores______ A. are most commonly found in Bacillus sp. and Clostridium sp. B. are never found in gram negative bacilli C. are mostly found in low G+C Gram positive bacteria D. never found in gram positive cocci

Answer 52

A & C

Question 53

T or F: Compound light microscope use halogen-quartz lamp light sources?

Answer 53

True

Question 54

T or F: A light micrscope allows us toview objects that are as small as 0,2 um (microns/micrometers).

Answer 54

True

Question 55

What is MAGNIFICATION?

Answer 55

Size of the image relative to the actual size of the object viewed

Question 56

What is resolution?

Answer 56

The smallest distance two closely adjacent objects can be clearly distinguished with the lens system that is set up.

Question 57

If you are using oil immersion lens what is the image magnification?

Answer 57

1000x

Question 58

Numerical aperture= (n) x (sin a) | True of false

Answer 58

True

Question 59

Where is the numerical aperture (NA) located?

Answer 59

Etched next to the magnification of the objective lens used

Question 60

Adjust the ocular lenses distance to accommodate your individual _________ _________.

Answer 60

interpupillary distance

Question 61

Always rotate the objective lens from highest to lowest magnification? True or False

Answer 61

False- You rotate from lowest to highest

Question 62

When going from 40x=400x to oil immersion, you add a drop of oil just before rotating the 100x= 1000x lens into place, then you focus with the (FINE) adjustment knob. True or False

Answer 62

True

Question 63

Most bacterial observations are best viewed with the condenser at it's (LOWEST or HIGHEST) point?

Answer 63

Highest

Question 64

What is located on top of the condenser? | What does it control?

Answer 64

Iris Diaphragm- controls the amount of light illuminating the specimen

Question 65

If you are viewing at low magnifications the amount of light for best observations should be ( HIGH or LOW)

Answer 65

Low

Question 66

Do high magnifications need more light or less light? What do you adjust to control the light amount?

Answer 66

More light can be added by opening the iris diaphragm

Question 67

The amount of light can be adjusted by the iris diaphragm and the ___/___ rheostat.

Answer 67

On/OFF

Question 68

T or F: Always use the coarse adjustment knob first? Where is the coarse adjustment knob located?

Answer 68

True, The coarse adjustment knob is the bigger of the two knobs and is located closest to the arm of the microscope

Question 69

The only focus knob that is used for 1000x is _____. | oil immersion

Answer 69

Fine focus knob- smaller of the two

Question 70

True or False Resolution = lambda / (2NA)

Answer 70

True

Question 71

In formula Resolution = λ / (2NA) Lambda (λ) is the ____A___ of light and NA is the objective lens __B___.

Answer 71

A wavelength | B. numerical aperture

Question 72

Calculate the resolution of a magnification system if you are using light at a wavelength of 5x10^-1 µm and the 4X objective lens with a NA = 10^-1 Resolution = lambda / (2NA)

Answer 72

= 5 x 10^-1 µm / 2 x 10^-1 = 2.5 x 10^0 µm = 2.5 µm

Question 73

Which response(s) is correct: Bacteria are very small in the range of .5-1 um. You need a magnification system to accommodate this: A. a higher magnification system B. a smaller wavelength of light C. Both D. All of the above

Answer 73

All of the above

Question 74

As the magnification of the objective lens increases, so does the _____ ______.

Answer 74

Numerical Aperture (NA)

Question 75

Inoculate mean:

Answer 75

Introduced

Question 76

What is a culture?

Answer 76

"the cultivation of microorganisms" / to grow If something is cultured in the laboratory it is GROWN there for test studies.

Question 77

To determine a bacteria's MORPHOLOGY, what is your main focus?

Answer 77

Shape, Size, Arrangement

Question 78

Pathology is ________

Answer 78

a branch of medical science primarily concerning the cause, origin and nature of disease.

Question 79

What is a pathogen?

Answer 79

a bacterium, virus, or other microorganism that can cause disease

Question 80

Bacteria are ___A__ and ___B__ in the laboratory for studies to determine their morphology and pathology.

Answer 80

A. Inoculated | B. Cultured

Question 81

The ________ (introduction) has to be performed without adding other microbes or contaminants

Answer 81

Inoculation

Question 82

What is the process of growing pure cultures and is essential for proper characterization of a bacterium?

Answer 82

Aseptic (sterile) techniques

Question 83

TRUE OR FALSE: In order to determine the cause of a disease the microbe must be separated from the mixture and cultured as a pure culture.

Answer 83

True

Question 84

What is the standard method of obtaining a "pure culture" on agar?

Answer 84

Streak Plate Method

Question 85

True or False: The streak plate method is an example of a solid dilution technique.

Answer 85

True

Question 86

T or F: In microbiology, streaking is a technique used to isolate a pure strain from a single species of microorganism, often bacteria.

Answer 86

True

Question 87

What is a dilution technique?

Answer 87

dilution technique- bacteria are obtained from a mixed culture with a sterile loop and diluted within three sectors on a petri dish containing appropriate growth medium. After incubation, as a result of this dilution technique, individual colonies of microbes can be obtained.

Question 88

After _________ (last step), as a result of dilution technique, individual colonies of microbes can be obtained.

Answer 88

Incubation

Question 89

``` Each individual colony represents the descendants of a ______ A. 2 cells B. 1 single cell C. 4+ cells D. virus ```

Answer 89

B. a single cell

Question 90

True or False: 1 million (10^6) bacteria are necessary to be VISIBLE to the naked eye.

Answer 90

True

Question 91

True or False: By inoculating the individual colony with a sterile loop onto a fresh agar surface, a pure culture may be obtained.

Answer 91

True

Question 92

T or F: Your aseptic technique was correctly done if you grew microorganisms in your CONTROLLED test tube.

Answer 92

False, the purpose of the controlled test tube in lab was to prove that you understand the steps of the aseptic technique. The main goal is to NOT have bacteria growth. If you didn't grow bacteria then consider yourself ASEPTIC TECHNIQUE TOP STAR!

Question 93

True or False: The hottest area on the Bunsen burner flame is the top portion of the light blue flame.

Answer 93

True

Question 94

``` The incubator is set to ____ degree Celsius. A. 32 B. 33 C. 35 D. 37 ```

Answer 94

D. 37 degrees Celsius

Question 95

T/F: If the petri dish is not in use it should be kept UPSIDE DOWN (media on top) to prevent dust from introducing microbes to the media and to prevent condensed water from falling on the media from the lid.

Answer 95

True

Question 96

True or False: The streak plate technique is the most popular method for isolating specific bacteria from a sample containing a mixture of microorganisms

Answer 96

True

Question 97

Basic stains have a positively charge auxochrome? T or F

Answer 97

True

Question 98

Negative stains are attracted to glass: True or False

Answer 98

True

Question 99

T or F: Positive stains are attracted to cell contents.

Answer 99

True

Question 100

T or F: Nigrosin is a basic stain

Answer 100

False: it is an acidic stain

Question 101

True or False | Methylene Blue is a basic stain.

Answer 101

True

Question 102

What is a simple stain procedure? A. consists of only one dye to increase cell contrast from a slide background. It shows simple cell structure. B. consists of at least two different dyes which highlight a biochemical reaction within the cell. It shows more than just simple cell structures. C. consist of 2 dyes and using the "cold method"

Answer 102

A.consists of only one dye to increase cell contrast from a slide background. It shows simple cell structure.

Question 103

What is a differential stain procedure? A) stain procedure consists of only one dye to increase cell contrast from a slide background. Shows simple cell structure B) stain procedure consists of at least two different dyes which highlight a biochemical reaction w/in the cell. Shows more than just simple cell structures.

Answer 103

B) stain procedure consists of at least two different dyes which highlight a biochemical reaction w/in the cell. Shows more than just simple cell structures.

Question 104

If your controlled test tube is cloudy, what does that mean?

Answer 104

You did not flame the mouth of the test tube You did not sterilize your loop long enough,You did not follow aseptic technique correctly

Question 105

True or False: Make sure you blow on your loop to help it cool faster.

Answer 105

False!

Question 106

How do you label your specimen?

Answer 106

Initials, Date, Name of Bacteria

Question 107

What does NB and NA mean in micro-lab?

Answer 107

NB- Nutrient broth | NA- Nutrient agar

Question 108

Steps when transferring Broth to Broth

Answer 108

1. label specimen 2. Flame loop/cool 3. Pick up tube with left hand & remove cap by curling small and ring finger of your right hand around the cap 4. Flame neck of tube & remove loop full of culture & flame tube again (briefly), place cap back on. 5. Now for the inoculation: remove cap from your test tube, flame mouth of tube & insert loop containing the culture into tube then remove. Flame mouth of tube again, replace cap. 5. Hold Loop at angle to sterilize it in the flame again, until loop is red THEN incubate at 37* C.

Question 109

Steps when transferring Broth to Plate:

Answer 109

1. obtain NA plate and label w/ initials, date, specimen 2. Flame loop & cool 3. Pick up bacteria tube, remove cap & flame mouth 4. insert loop into bacteria culture & remove loop full of broth, flame mouth, replace cap 5. Streak NA plate using the 3 streak method 6. Once streaking method is completed, sterilize loop until red/cool 7. Incubate plate, INVERTED, in 37*C.

Question 110

Steps for Plate to Plate transfer:

Answer 110

1. label the 2nd NA plate on the bottom w/ initials,date,specimen name "plate to plate" 2. obtain stock plate of bacteria and place plate upside down on the bench near flame 3. Flame loop & cool 4. pick up plate of specimen, open lid & use sterile loo[ to remove one colony from plate. Place lid back quickly 5. pick up NA plate, leave lid on table by flame & start 3-sector streak. Replacing lid AFTER EACH SECTOR HAS BEEN STREAKED. Sterilizing loop between each sector streaking. 6, Flame loop to sterilize it 7. Incubate plate, inverted, in 37*C