Lab Exam 1 Flashcards
1
Q
What objective lens should only be used for oil immersion and bacteria spears?
A
100x
2
Q
What should you do to put away a microscope?
A
- turn nosepiece to empty slot
Lower stage to lowest position
3
Q
What objective should you use the course focus knob?
A
10x ONLY; go all the way up until clear
4
Q
The circle of light is
A
The field of view
5
Q
When should the iris diaphram be closed?
A
When the specimen is dyed lightly ; it’s more translucent
6
Q
Which micropipetters have yellow tips
A
P-20 & P-200
7
Q
P-20 range
A
2-20
8
Q
P-200 range
A
20-200 microliters
9
Q
P-1000 rang,e
A
100-1000 microliters
10
Q
P-1000 tips are
A
Blue
11
Q
Why do we release the plunger slowly?
A
To prevent liquid from splashing up and contaminating the shaft
- reduce air bubbles
12
Q
What angle should you hold a micropipetter?
A
Always straight up
13
Q
Why should you wait -2 seconds before withdrawing tip from the liquid?
A
To ensure the right amount of liquid is picked up ( correct volume)
14
Q
What is the purpose of the second stop?
A
To expel the remaining liquid
15
Q
Where do slides go?
A
In the used slide box of water
16
Q
Where do coverslips go?
A
Broken glass box
17
Q
What needs to be done before placing slides on the lab cart?
A
Remove the ink and any writing
18
Q
What do you place on the back counter?
A
Sterile/ clean supplies
- micropipetters
- tip boxes
- prepared slides
19
Q
What does contaminated mean?
A
Unwanted microorganisms; when a pure media has more than one microorganism present
20
Q
How do you label a plate
A
Initials, date, section, description of experiment
21
Q
Where do you label a peri dish and why?
A
On the bottom where the agar is - if you lose the lid you can still know what you are working with
22
Q
Pure culture
A
Only one microorganism
23
Q
Sterilization
A
Killing all microorganisms
24
Q
Where does broken glass go? Contaminated?
A
Regular = Broken glass box
Contaminated = biohazard bag
25
Steps to clean a bacterial spill
1. Inform instructor/ lab partners and remove all items out of the way
2. Circle with microban
3. Place paper towels on top of spill
4. Drench paper towels with microban
5. Using gloves, place into a biohazard bag
6. Repeat steps 2-5 at least once
7. Wash your hands
26
Culture media
Nutrient solutions used to grow microbes in the lab
27
What is Aseptic techniques?
Steps or procedures to prevent contamination
28
Why should the lip of test tubes be sterilized?
To decontaminate the lip and to create no air flow so bacteria doesn’t get in
29
What angle should you hold test tubes when transferring one media from another?
45 degrees ; to prevent bacteria from entering and to make it easier to put loop inside
30
How are peri plates placed inside the incubator? Why?
Upside down; lid facing down to prevent contamination
31
Why do you move the inoculation loop from handle to loop?
To reduce aerosols
32
How many times do you flame the lip of the test tube?
2- right after opening and before closing
33
How far should you insert the loop into the test tube?
Just below the surface @ the 45 degree angle
34
Where should you do ALL transferring media to another and transferring media to a peri plate?
Near the Bunsen burner ; it’s the sterile area
35
Aerosols
Spray of bacteria
36
Ubiquitous means
Present or existing everywhere
37
Why did we leave one plate unopened in the ubiquity lab?
For a negative control ; showing if we did the experiment correctly
38
Colony
Visible mass of microbial cells arising from one cell or from a group of the same microbes
39
Colony morphology
Distinguishes one microb from another ; shape, color, size, texture
40
Where did the bacteria from plate A in the ubiquity lab?
Microbes were in the air from water, soil, skin, floor
41
Why is post washing have more colonies then the pre washing?
- skin cells scratched off
42
Singular bacteria
Bacterium
43
What is the technique used to isolate colonies?
Streak plate
44
What is the process of isolating colonies?
Dilution
45
How many times do you dip into the original bacterium you want to isolate?
Once
46
True or false
You close the lid every time you are waiting for loop to cool down
True; it prevents unwanted microorganisms from going in
47
How many times do you go back in a zone when streak plating?
Twice for 2& 3 and once for zone 4
48
How do you smear culture onto media
Smear zigzags by holding loop flat against the agar
49
True or false
You sterilize inoculating loop once during streak plating
False; you flame sterilize in between each zone and inoculate before starting
50
What are the 3 kingdoms in the eukaryotes lab?
Fungi, protists, helminths
51
Reproductive capabilities of fungi
Reproduce sexually and asexually via spore
52
How do fungi obtain nutrients?
Secrete digestive enzymes outside their body and absorb the nutrients
53
What fungi is unicellular?
Yeast
54
Hyphae
Long filaments of cells that make up the body of fungus
55
Aerial hyphae
Involved in reproduction by bearing reproduction spores
56
What is a bud?
A cell sharing its nucleus to create another cell attached to it
57
Where can saccharomyces (yeast) be found?
Seen as white powdery coating on fruits and vegetables
58
Asexual spores
Formed by hyphae of one organism
59
Sexual spores
Fusion of nuclei from 2 fungi
60
Asexual spores include
Condiospores and sporangiospores
61
Sporangia
Sac held up by sporangiophores
62
Sporangiophores
Specialized hyphae where sporangia are supported
63
What is the difference between condiospores and sporangiospores
Condiospores not in a sac (enclosed)
64
Vegetative hyphae
Digest and absorb nutrients
65
Genus of fungi
Saccharomyces, penicillium, rhizopus, aspergillus, coccidiodes
66
Genus of helminths
Trichinella, clonorchis, Echinococcus
67
Genus of protists
Plasmodium, trichomonas, trypanosoma
68
Are fungi motile?
No- they are nonmotile
69
Mycosis
A fungal infection
70
What is the dangers of rhizopus?
Can cause systemic mycosis
71
Systemic mycosis
Fungal infection deep in tissues and organs ; widely spread
72
Local mycosis
Fungal infection in one area
73
What are the dangers of aspergillus?
Causes aspergillosis
74
How are most fungal infections acquired by people?
Inhalation of spores
75
What genuses have Condiospores and condiophores ?
Aspergillus and penicillium
76
Where is aspergillus found?
Compost ; dead leaves and decaying matter
77
What disease does coccidioides cause?
Valley fever
78
What type of environment do coccidioides thrive in?
Dry alkaline soil
79
What are Protozoa?
Unicellular heterotrophic organisms ( part of eukaryotes)
80
Where do Protozoa live?
Water, soil, animal hosts
81
How do Protozoa reproduce s
Sexually and asexually
82
What human disease is cause by trypanosomes?
Chagas disease
83
How are trypanosomes transmitted to humans?
Kissing bug bite
84
What disease is caused by plasmodium?
Malaria
85
Intermediate host
An organism that supports the immature or nonreproductive form of a parasite
86
Definitive host
Host in which the sexual reproduction of a parasite takes place - larvae are here
87
How is plasmodium transmitted?
Anopheles mosquito
88
What cells are affected by plasmodium?
Red blood cells, liver cells
89
How is trichomonas transmitted?
Sexual intercourse
90
What disease does trichomonas cause
Vaginitis
91
How do helminths feed?
Absorb nutrients from hosts body
92
What is the definitive host and intermediate host for echinococcus
Dog tapeworm - definitive
Human - intermediate
93
What is a proglottid
Segment of tapeworm where male and female reproductive organs are
94
How do humans get infected with echinococcus
Through dog licks or picking up dog feces
95
Function of scolex in echinococcus
Attach to intestines of definitive host to stay in place
96
Where do clonorchis live in the host
Liver
97
How do humans contract clonorchis and trichinella (round worm)
Eating undercooked meat
98
What muscles are affected by trichinellosis?
The diaphragm and eye muscles
99
Definitive host of trichinella
Roundworm
100
What region of the world do clonorchis live
Asia (china)
101
Where do the eggs of helminths usually go?
Excreted through feces of definitive host
102
Mycelium
Mass of vegetative hyphae
103
Shapes of bacteria
Coccus, bacillus, spirillum
104
Coccus
Round shaped
105
Bacillus
Rod shaped
106
Spirillum
Spirillum shaped
107
Arrangements of bacteria
Pair: diplococcus, diplobacillus
Cluster: staphylococcus
Chains - streptococcus’ streptobacillus
108
Spirillum under microscope looks like
Tiny pale pink worm like
109
True motility
Directional, independent movement
110
Brownian movement
A vibratory movement of cells due to their bombardment by water molecules in the suspension
111
Heat fixing
Kills bacteria, making them adhere to the slide, maintaining their cell structure
112
How do you heat fix?
You pass the slide through the flame 3 times
113
What happens when the bacteria spear is not dry before you heat fix?
Cells will burst
114
Are bacteria negatively or positively charged?
Negative charge
115
Simple stain steps
1. Sterilize loop, wait 30 seconds and put water droplet onto the slide
2. Grab bacterium and smear the size of a quarter
3. Sterilize loop and let slide dry
4. Heat fix ( put slide through flame 3 times)
5. Add crystal violet, wait 30 seconds and wet with water and pat dry
116
Simple stain
Use of a single basic dye
117
Example of basic dye
Crystal violet
118
Basic dye is
A cation
119
Acidic dye
An anion
120
Why do you rinse a slide above it?
If you spray directly on the bacterium it will wash it off
121
Positive stain
Dye sticks to the specimen baking it purple
122
Negative stain
Colors the background, making the capsule more visible
123
What is the purpose of hanging drop?
Observe true motility versus brownian movement
124
What color are bacteria in hanging drop?
Colorless because there is no stain
125
What structures allow a bacteria to move?
Flagella and axial filaments
126
Steps for a hanging drop
1. Pot Vaseline on the 4 corners of cover slip
2. Using aseptic techniques put a culture on the center of coverslip
3. Grab depression slide and place over coverslip
127
What does gram stain do?
It distinguishes between two different kinds of bacteria cell walls
128
What are the 2 classifications of gram staining?
Positive and negative gram stain
129
Differential stain
A stain that distinguishes objects on the basis of reaction to the staining
130
Gram positive will be
Purple
131
Gram negative will be
Red/ pink
132
Why does a gram positive remain purple
Think layer of peptidoglycan hold a primary stain
133
Primary stain in gram staining
Crystal violet
134
Mordant in gram staining
Iodine
135
Decolorizing agent in gram staining
Ethanol
136
Counterstain/ second stain in gram staining
Safranin
137
Why does gram staining not work with old dead cells?
The positive gram will eventually turn to a negative stain
138
When does gram staining work best?
With young bacteria (less than 24 hours)
139
Why does gram negative get washed away?
Ethanol dissolved the outer membrane and crystal violet - iodine complex wash out due to having a thin peptidoglycan
140
What does ethanol do negative gram?
Disrupts the outer lipopysaccaride layer
