Term
| describe the position of your hands when carrying the microscope to and from your laboratory bench. |
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Definition
| one hand on body, and one hand on base. |
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Term
| differentiate between the limit of resolution of the typical light microscope and that of the unaided human eye. |
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Definition
unaided eye = .2mm
microscope = 0.2 micrometer |
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Term
| what two adjustments can be made to the condenser? what effect do these adjustments have on the image? |
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Definition
up and down
focus's the light on the object |
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Term
| why are condenser adjustments generally preferred over the use of the voltage control? |
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Definition
| lamp life is greatly extended when used at low voltage |
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Term
| when using the oil immersion lens, what four procedures can be implemented to achieve the maximum resolution? |
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Definition
1)place drop of immersion oil on slide
2)oped diaphragm as much as possible
3)apply colored filters if needed
4)raise condenser to highest position |
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Term
| why is it advisable to start first with the low-power lense when viewing a slide? |
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Definition
| to easily find the object that your viewing. |
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Term
| why is it necessary to use oil in conjunction with the oil immersion lens and not with the other objectives? |
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Definition
| slight is lost through refraction and oil acts as a continuous medium so light is not lost. |
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Term
| what is the relationship between the working distance of an objective lens and its magnification power? |
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Definition
| the working distance decreases as the magnification increases. |
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Term
| in which domains are algae, protozoa, and cyanobacteria classified? |
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Definition
| cyanobacteria = bacteria, protozoa = eukaria, algae = eukaria |
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Term
| name one similarity between algae and plants. name one difference |
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Definition
| both contain chlorophyll, plants use connective tissue to transport nutrients, algae cells are responsible for their absorption of water. |
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Term
| compare and contrast the three mechanisms of motility displayed by protozoa. |
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Definition
| protozoa move by using structures that propel them known as flagella and cilia, protozoa move by extending cytoplasmic extensions known as pseudopodia. |
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Term
| what organisms were formerly known as blue-green algae? why are these organisms not algae? |
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Definition
| cyanobacteria, they do not have an organized nucleus, chloroplasts, or organelles. |
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Term
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Definition
| large influx of nutrients come into the water, causing a growth or red colored marine dinoflagellates, red pigment in the algae |
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Term
| what is the genus of the causative agent of malaria? in what group does it belong? |
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Definition
| plasmodium, group = apicomplexa |
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Term
| what are the five distinguishing characteristics of fungi? |
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Definition
| eukaryotic, heteratrophic, lack tissue differentiatino, have cell walls of chitin or other polysaccharides, propagate by spores |
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Term
| differentiate between molds and yeasts. what term is given to fungal species that have both a mold and a yeast phase? |
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Definition
molds = contain hyphae, mycelium, septa
yeasts = lack hyphae, multiply by budding,
dimorphic |
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Term
| differentiate between hyphae and mycelia |
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Definition
hyphae = intertwining fillaments, microscopic
mycelia = a mass of hyphae, macroscopic visible mass |
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Term
| what characteristic determines that fungal hyphae are coenocytic? |
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Definition
|
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Term
| what are the types of asexual spores of fungi? |
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Definition
| sporangiospores, conidia, phialospores, blastospores, arthrospores, chlamydospores |
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Term
| what are the types of sexual spores of fungi? |
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Definition
| zygospores, ascospores, basidospores |
|
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Term
| describe how sparangiospores differ from conidia. |
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Definition
sporangiospores = formed within sporangium, sometimes motile
conidia = form on outside, non-motile |
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Term
| What is the function of a mordant? |
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Definition
| is what fixes the stain into the cell wall of the bacteria. |
|
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Term
| For differential staining, how does a counterstain differ from a primary stain? |
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Definition
| It's a different color from a primary stain. |
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Term
| How do gram-positive and gram-negative bacteria differ in cellular structure? |
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Definition
| Gram- are thin cell walls and are pink (fusia). Gram+ are thick cell walls and are purple and made of peptiglycan. |
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Term
| Which is the most critical step in the Gram-stain procedure? Why? If this procedure is done incorrectly, how might that affect the final results? |
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Definition
| The most critical step in the Gram stain is the decolorizer step with acetone alcohol. If the decolorizer is left on too long Gram positive bacteria will come out pink and if it is not left on long enough the Gram negatives will come out purple. |
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Term
| How does culture age affect the results of a Gram-stain? |
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Definition
| gram+ will get old and will look pink. The cell wall gets old and thin and stains pink. |
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Term
| How does culture age affect the results of a spore stain? |
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Definition
| old culture have more spores, bacteria produce more endospores when they are old. |
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Term
| Why must smear thickness be considered before performing a Gram-stain ? |
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Definition
| If they are too thick gram - will not decolorize properly. |
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Term
| What color are bacterial endospores after a Gram-stain is performed? What does this tell you about the physical properties of endospores? |
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Definition
| clear inside and around them. They are so thick they will not take up the stain. |
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Term
| What makes Mycobacterium particularly resistant to staining? How are the bacteria in this genus grouped in terms of Gram classification? |
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Definition
| They have an extra thick cell wall with mycolic acid. |
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Term
| How do you think the acid-fast nature of Mycobacterium contributes to its virulence? |
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Definition
| to survive enzamatic digestion once it is phagocytized and it can then grow and take over the macrophage. |
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