Micro Exam

hrdcorhrvivor's version from 2017-03-08 08:22

Section 1

Question Answer
uniform turbiditycloudy throughtout broth, usually contains "swimmers"
sedimentgrowing on the bottom
ring (broth)microbes growing in ring like pattern
complete pellicle "plug"microbes covering the top of broth
flocculencescattered visible growth
science is an explanation of structures and processes based on what?verifiable observations and measurements
what are scientific ideas subjected to?rigorous and repeated testing
inductive reasoningdiscoveries based primarily on observations, specific observations that lead to general conclusion
deductive reasoningtype of reasoning that goes from a general idea to a specific conclusion
state the steps of scientific method (5)1. observations 2. question 3. hypothesis, tentative answer to the question 4. prediction 5. test by experiment
hypothesispossible answer to one question
scientific theorycomprehensive explanation supported by abundant evidence
how do theories become accepted?if they are supported by accumulation of extensive and varied evidence
what microbe causes gas gangreneClostridium perfringes
what microbe causes tetnusClostridium tetani
what microbe causes botcholismClostridium botulinum

Section 2

Question Answer
when should you wash hands (in relation to gloves)before gloves, between changing, and after
what should you do if there is a spill?cover spills with paper towels then spray the towels with disinfectant, wait 10-20 minutes
scanning lens TM40
low power lens TM100
high power lens TM400
oil immersion lens TM1000
substage featuresiris diaphragm and iris diaphragm lever, condenser lens
rheostatlight intensity control knob
brightfield light microscopevisible light transmitted through specimen
reversalproperty of microscopes where the image seen through occulars is upside down and backwards
field of viewlighted circle visible through oculars
compound microscopetwo kinds of magnifying lenses are present, ocular lenses and objective lenses
parfocal lensonce image is in focus under low power, it stays in focus when higher power is clicked into place
working distanceamount of space between tip of objective lens and slide when its in focus
resolving power ability to see fine details and distinguish two points as seperate
plane of focus set distance from objective lens at which every part of specimen that falls at imaginary level remains in focus
depth of fieldthickness of plane of focus and each mag. lower mag. greater depth of field
human eye can seeabout .2 mm
light microscope can seeabout .2 um
scanning electron microscope can seeabout 10 nm
transmission electron microscope can seeabout 10 pm

Section 3

Question Answer
name three things you might find in pond waterinsect larvae, rotifer, green algae
simple stainsingle dye used, reveals cell morphology and arrangement
differential staintwo or more dyes used, distinguishes between kinds of organisms, between different parts of the same cell, top differential stains are gram, acid fast, and endospore
positive staindye will attach and color cell/structure
negative stain dye repelled by cell, cell colorless, background colored
dyes (stains)chemicals made of ions, one which is colored (the chromophore)
basic dyepositive binds to negatively charged particles like nucleic acids or prokaryotic cytoplasm. common basic dyes: crystal violet, safranin, methylene blue
acidic dyesnegative binds to positively charged particles like eukaryotic cytoplasm. common acidic dyes: nigrosin, congo red, eosin
Bacillus cereusspores multiply in rice/grain if not cooked thoroughly
primary stainfirst dye used in staining protocol
mordantchemical used to retain and intensify primary stain
decolorizerchemical that removes primary stain from some cells but not others
counterstainsecond stain used

Section 4

Question Answer
atrichousno flagella
monotrichousone flagellum
lophotrichousmultiple flagella per one cell
amphitrichousboth ends have flagella, one cell
peritrichousflagella all around the cell
name the ten steps to aseptic technique1. flame the loop 2. remove cap properly 3. flame lip of the tube 4. get loop full of specimen 5. apply specimen to slide 6. flame lip of the tube 7. recap tube 8. flame the loop 9. air dry 10. heat fix
what would be seen in an oral smear?a large eukaryotic cell with prominent nucleus, prokaryotic G- and G+ cells, cell membrane, cytoplasm, spirili and rods
how are endospores made? 6 steps1. spore septum isolates new replicated DNA in cytoplasm 2. PM surrounds DNA, cytoplasm, and membrane isolated 3. spore septum surrounds isolated portion 4. peptidoglycan layer forms 5. spore coat forms, tough water resistant coat 6. endospore freed from cell

Section 5

Question Answer
simple positive stainheat fixed emulsion, cover slide with stain, wash stain with water
simple negative stainbegin with drop of acidic stain, aseptically add organism, take spreader slide and draw it back, dispose of spreader slide in jar of disinfectant, air dry @ room temp
flagellar stainmordant used to coat flagella, metal ions used to stain flagella, carbolfuchsin sometimes used
gram stainheat fixed emulson, PS crystal violet, wash with water, M iodine, wash with water, DC ethanol, wash with water, CS safranin
acid fast stainheat fixed emulsion, PS carbolfuchsin over steam generator, wash with water, DC acid alcohol, wash with water, CS methylene blue
endospore stainheat fixed emulsion, PS malachite green over steam generator, DC water, CS safranin
capsule stainPS congo red, aseptically add organisms, drag clean slide to spread across slide, air dry, CS maneval's stain
gram - cells colorpink from safranin, thin peptidoglycan
gram + cells colorpurple/blue from crystal violet, thick peptidoglycan
AF - cells colorblue from methylene blue
AF + cells colorreddish purple from carbolfuchsin
spore producing cells colorpinkish outer cell from safranin, greenish inner cell from malachite green
nonspore producer cells colorpinkish from safranin