Term 1

microscope base

Definition 1

bottom of the microscope

Term 2

microscope arm

Definition 2

with the base, used to carry the microscope

Term 3

microscope stage

Definition 3

holds the slide
-

Term 4

microscope body tube

Definition 4

transmit the magnified image

Term 5

microscope condenser

Definition 5

lenses that focus light into a cone

Term 6

microscope iris diaphragm

Definition 6

controls the angle and size of the cone of light
-

Term 7

microscope revolving nosepiece

Definition 7

holds objective lenses

Term 8

microscope obective lenses

Definition 8

magnify & invert the image

Term 9

microscope focal point

Definition 9

formed when light rays converge at one point
-

Term 10

microscope coarse adjustment

Definition 10

larger knob used to focus on low power

Term 11

microscope fine adjustment

Definition 11

smaller knob used to focus with high power and oil immersion

Term 12

microscope field of vision

Definition 12

area seen through the microscope
-

Term 13

microscope magnification

Definition 13

the number of times an image is increased in size

Term 14

formula for magnification

Definition 14

determined by multiplying the power of the objective by the power of the ocular lens

Term 15

resolution

Definition 15

ability to distinguish two points as distinct and separate
-

Term 16

refractive index

Definition 16

the amount light bends when it enters a new medium

Term 17

parfocal

Definition 17

when one lens is focused, all the other lenses will also be in focus

Term 18

which lens has the shortest focal distance?

Definition 18

oil immersion
-

Term 19

the three basic bacterial shapes

Definition 19

rods (bacilli), spheres (cocci), spirals

Term 20

the field of vision decreases when the magnification...

Definition 20

increases

Term 21

why does immersion oil increase resolution?

Definition 21

it has the same refractive index as glass (1.52) and the light does not bend between the slide and the objective lens
-

Term 22

when viewing large organisms like fungi or protozoa, it is best to use the ___________ lens

Definition 22

low power

Term 23

spherical aberration

Definition 23

when the middle of the field of view is in focus but the periphery is blurry. Light passing through the middle of the lens has a different focal point than light passing through the outside

Term 24

chromatic aberration

Definition 24

many colors appear in the field. occurs when each wavelength of light has a different focal point
-

Term 25

In bright field microscopy, the image is made from:

Definition 25

light that is transmitted through a specimen

Term 26

Bacterial stains will _____ the organism

Definition 26

kill

Term 27

The condenser lens ___________ the light

Definition 27

concentrates
-

Term 28

Refraction is ________ of light rays

Definition 28

bending

Term 29

A microscope produces 2 images.

One is _____ and one is ______.

Definition 29

real

virtual

Term 30

The virtual image appears ___________ the microscope

Definition 30

below or within
-

Term 31

The formula for calculating magnification:

Definition 31

total magnification =

 

magnification by the objective lens

x 

magnification by the ocular lens

Term 32

Resolution is defined as:

Definition 32

clarity of an image

Term 33

The limit of resolution is:

Definition 33

an actual measurement of how far apart two points must be for the microscope to view them as being separate
-

Term 34

Write the formula for the limit of resolution:

Definition 34

λ

D=-----------------------------------

NAcondenser +NAobjective

Term 35

Numerical Aperture is:

Definition 35

a measure of a lens's ability to "capture" light coming from the specimin and use it to make the image

Term 36

Using immersion oil makes the numerical aperture__________

Definition 36

increase
-

Term 37

In dark-field microscopy, objects appear ________ 
against a _________ background 

Definition 37

brightly lit

dark

Term 38

In phase contrast microscopy, the specimen appears as various levels of ______ against a bright background

Definition 38

"darks"

Term 39

Fluorescent microscopy uses fluorescent ______

that emit light when illuminated with

_____________ light

Definition 39

dye

ultraviolet

 
-

Term 40

A mixed culture contains:

Definition 40

two or more species

Term 41

A pure culture contains:

Definition 41

only a single species

Term 42

The purpose of streaking bacteria on a plate is to:

Definition 42

isolate an individual species from a mixed sample
-

Term 43

Individual cells grow into:

Definition 43

colonies

Term 44

CFU stands for:

Definition 44

colony-forming unit

Term 45

A CFU consists of:

Definition 45

individual cells or pairs, chains, or clusters of cells
-

Term 46

Ubiquitous:

Definition 46

Organism can be found everywhere, could be isolated from soil, water, plants, and animals

Term 47

Define pathogenic:

Definition 47

capable of causing disease

Term 48

Define opportunistic pathogen

Definition 48

capable of causing disease if introduced into a suitable part of the body
-

Term 49

define reservoir:

Definition 49

any area where a microbe resides and serves as a potential source of infection

Term 50

Pellicle

Definition 50

organisms float on top and produce a surface membrane

Term 51

sediment

Definition 51

organisms sink to bottom
-

Term 52

turbidity

Definition 52

evenly distributed throughout

Term 53

flocculent

Definition 53

suspended chunks

Term 54

Organisms that can infect us:

Definition 54

Amoeba (Entamoeba histolytica causes dysnetery)

Nematodes

(Enterobius vermicularis - pinworm - intestines

Ascaris lumbricoides - intestines

Necator americanus - intestines

Trichinella spirallis - muscles)

Ciliates (Balantidium coli - intestines)

 
-

Term 55

Organisms that may transmit disease

Definition 55

arthropods

Term 56

most commonly used staining method

Definition 56

gram staining

Term 57

gram staining - which stain is applied first?

Definition 57

crystal violet
-

Term 58

gram staining

 

what forms inside the cell after you add iodine?

 

 

Definition 58

crystal violet-iodine complex

Term 59

gram staining

 

what type of cell is decolorized?

Definition 59

gram negative

Term 60

gram staining

 

Name the counterstain

Definition 60

safranin
-

Term 61

what effect does alcohol have on the gram-negative cell wall?

Definition 61

the alcohol extracts the lipid, making the gram negative cell wall more porus and unable to retain the crystal-iodine complex, decolorizing it

Term 62

Explain why gram-positive cells are not decolorized

Definition 62

the thicker peptidoglycan traps the crystal violet-iodine complex more effectively, making them less susceptible to decolorization

Term 63

What color will gram-positive cells be if the decolorizer is left on too long?

Definition 63

reddish
-

Term 64

Describe the appearance of a good emulsion

Definition 64

dries to a faint haze on the slide

Term 65

what happens to older gram-positive cultures?

Definition 65

may decolorize and give a gram negative result

Term 66

In the negative staining technique a chromogen (dye) has a ____________ charge.

Definition 66

negative
-

Term 67

The pH of negative stains is_____________

Definition 67

acidic

Term 68

Negative stains do not enter bacterial cells because the charges ____________ each other.

Definition 68

repel

Term 69

Negative staining is commonly employed for bacteria that are:

Definition 69

too delicate to withstand heat-fixing
-

Term 70

Acid-fast bacteria have ____________ in their cell walls

Definition 70

mycolic acid

Term 71

Acid-fast organisms resist _________ by _________ alcohol.

Definition 71

decolorization, acid

Term 72

The names of the 2 acid-fast staining procedures are:

Definition 72

Ziehl-Neelsen (ZN)

Kinyoun (K)
-

Term 73

When preparing an acid-fast smear, a drop of __________ is used to help the ____________ organisms adhere to the slide

Definition 73

serum, slippery

Term 74

The primary stain in the ZN method is _________ because it is soluble in _____________

Definition 74

carbolfuchsin, lipid

Term 75

Heating causes acid-fast cell walls to _________

Definition 75

melt
-

Term 76

the counterstain in an acid-fast stain is

Definition 76

methylene blue

Term 77

Acid fast cells are colored

Definition 77

reddish purple

Term 78

Non acid-fast cells are

Definition 78

blue
-

Term 79

Capsules are made of __________ or _________

Definition 79

mucoid polysaccharides, polypeptides

Term 80

(Capsule stain) Two examples of netgaive stains are:

Definition 80

Congo red, nigrosin

Term 81

(Capsule stain) Negative stain pH is ___________ and they stain the background

Definition 81

acidic
-

Term 82

(Capsule stain) A basic stain is used to stain _________

Definition 82

the cell

Term 83

(Capsule stain) We do not heat fix because:

Definition 83

it causes the cells to shrink, leaving an artifactual white halo that may be interpreted as a capsure

Term 84

Cells stick to the slide by adding a drop of ___________

Definition 84

serum
-

Term 85

An endospore is:

Definition 85

A dormant form of the bacteria that allows it to survive poor environmental conditions

Term 86

Endospores are covered with a protein called:

Definition 86

keratin

Term 87

(endospore stain) The primary stain is called:

Definition 87

malachite green
-

Term 88

(endospore stain) The decolorizer is:

Definition 88

water

Term 89

(endospore stain) The cells that are counterstained with safranin are ______________ and _____________

Definition 89

vegetative cells, spore mother cells

Term 90

Location of endospore: central

Definition 90

In the middle of the cell
-

Term 91

Location of endospore: terminal

Definition 91

at the end of the cell

Term 92

location of endospore: subterminal

Definition 92

between the end and the middle

Term 93

Two spore shapres are:

Definition 93

spherical, elliptical (oval)
-

Term 94

some spores are large and make the cell look:

Definition 94

swollen

Term 95

Why can't we view flagella using an unstained preperation?

Definition 95

flagella are too thin to be observed with light microscope and ordinary stains

Term 96

flagella - monotrichous

Definition 96

one flagellum at one end
-

Term 97

flagella - amphitrichous

Definition 97

flagella at both ends

Term 98

lophotrichous

Definition 98

tufts of flagella at one end

Term 99

peritrichous

Definition 99

flagella all over the cell
-

Term 100

Why does light of a shorter wavelength produce a clearer image than light of longer wavelengths?

Definition 100

As wavelength gets smaller, resolution gets smaller because wavelength is on the top of the equation

Term 101

Colony morphology includes:

Definition 101

colony size, color, shape, margin, elevation, texture

Term 102

colony morphology - shape

Definition 102

round, irregular, punctiform
-

Term 103

colony morphology - margin

Definition 103

entire, undulate, lobate, filmentous, rhizoid

Term 104

colony morphology - elevation

Definition 104

flat, raised, convex, pulvinate (very convex), umbonate (raised in center)

Term 105

colony morphology - texture

Definition 105

moist, mucoid, dry
-

Term 106

colony morphology - color

Definition 106

opaque, translucent, shiny, dull

Term 107

colony morphology - other factors

Definition 107

length of incubation, temperature of incubation, type of medium grown on, oxygen concentration during incubation

Term 108

Why are microorganisms located on the desks not sterilized as extremely as the plates?

Definition 108

Bugs that grow on desks at 25 degree C are probably not human pathogens. Plates have many more bugs on them as well.
-

Term 109

What is significant about organisms that grow well at 37 degrees C?

Definition 109

They probably came from humans.

Term 110

Capsule stain - why must the sample be emulsified in serum?

Definition 110

To help them stick to the slide because they are slippery.

Term 111

Why do oral bacteria produce a capsule?

Definition 111

protection against phagocytocis and to stick to surfaces and each other forming a biofilm
-

Term 112

Why was an older culture of Bacillus used to demonstrate endospores?

Definition 112

Spores are formed in response to nutrient depletion, so the 

Term 113

Why can't flagella be observed in action?

Definition 113

Because they are too thin to be seen with regular stain. A mordant must be used to encrust the flagella so it is thick enough to be seen.

Term 114

Type of microscopy:

Definition 114

bright field microscopy
-

Term 115

Definition 115

Term 116

Type of microscopy:

 

Definition 116

dark field microscopy

Term 117

type of microscopy:

Definition 117

fluorescence microscopy
-

Term 118

type of microscopy:

 

Definition 118

phase contrast microscopy

Term 119

bacterial morphology:

 

Definition 119

gram positive cocci

Term 120

bacterial morphology

 

Definition 120

ovoid coccus (Lactococcus lactis)
-

Term 121

bacterial morphology

 

Definition 121

gram positive bacilli (Bacillus)

Term 122

bacterial morphology

 

Definition 122

gram positive staphylococci

Term 123

bacterial morphology:

Definition 123

gram positive streptobaccillus
-

Term 124

bacterial morphology:

Definition 124

gram positive spirilla

Term 125

bacterial morphology:

Definition 125

spirochetes

Term 126

bacterial morphology:

Definition 126

gram negative vibrio (Vibrio cholera)
-

Term 127

bacterial morphology:

Definition 127

gram negative diplococci (Nesseria gonorrhea)

Term 128

bacterial morphology:

Definition 128

tetrads (Micrococcus roseus)

Term 129

bacterial morphology:

Definition 129

gram positive streptococci

(Streptococcus pyogenes)
-

Term 130

bacterial morphology

Definition 130

gram positive bacilli, palisades arrangement

(Corynebacterium)

Term 131

How to do a plate streak:

Definition 131

Term 132

Broth growth:

 

 

Definition 132

1- obligate aerobes (need oxygen) - growth at top

2 - faculative anaerobes - growth throughout, but more growth at top

3- microaerophiles

4 - anaerobes - growth at bottom, no growth at top where oxygen is present
-

Term 133

Gram stain procedure

Definition 133

1 - heat fix emulsion

2 - cover smear with crystal violet stain for 30-60 sec

3 - rinse with distilled water

4 - cover smear with iodine for 30 - 60 sec

5 - rinse with distilled water

6 - decolorize with alcohol

7 - counterstain with safranin for 30 - 60 sec

8 - rinse with distilled water

9 - blot dry with bibulous paper

Term 134

gram positive vs gram negative results:

Definition 134

gram positive - dark purple

gram negative - pinkish red

Term 135

Negative stain:

Definition 135

Bacteria are unstained against dark background
-

Term 136

acid-fast stain (ZN)

Definition 136

in ZN stain, acid fast cells are reddish-purple (non acid fast cells are blue)

Term 137

acid fast stain (K)

Definition 137

acid fast cells are reddish purple (non acid fast cells are blue)

Term 138

capsule stain:

Definition 138

acidic stain colorizes the background while the basic stain colorizes the cell, leaving the capsules as unstained white clearings around the cell
-

Term 139

Flagella stain:

Definition 139

peritrichous flagella

Term 140

flagella:

Definition 140

monotrichous

Term 141

flagella:

Definition 141

amphitrichous
-

Term 142

flagella:

Definition 142

lophotrichous

Term 143

Endospores:

Definition 143

terminal swollen

Term 144

endospores

Definition 144

central