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Micro- XULA
Micro Notes CH-2
Question | Answer |
---|---|
Name the types of light microscopes. | Light, Dark, Phase-Contrast, Flourescence |
Bending of light rays at the interface of one medium with another | Refraction |
A measure of how greatly a substance slows the velocity of light is _____ | Refractive Index |
The direction and magnitude of bending is determined by the _______ | Refractive indexes |
Lenses focus light rays at a specific place called the ______ | Focal Point |
What is the focal length? | Distance b/w center of lens and focal point |
The strength of the lens is related to _____ length | Focal |
Short Focal Length--> More Magnification. (T/F) | True |
What produces a dark image against a bright background? | Bright-Field Microscope |
Product of the magnifications of the ocular lens and the objective lens is _____ | total magnification |
Whats the magnification and resolution of the Bright-Field microscope? | M-2000X R-0.2 nanometers |
Common multipurpose microscope for live and preserved stained specimen is the ____ | Bright-Field Microscope |
Shorter Wavelength-->Greater Resolution (T/F) | True |
Wavelength of light used is a major factor in ______ | resolution |
Produces a bright image of the object against a dark background. | Dark-Field Microscope |
What's used to observe living, unstained preparations? | Dark-Field Microscope |
A Magnification of 2000X and a Resolution of 0.2 nanometers is/are used by which microscope(s) | PhaseContrast/Dark/Light-Field Microscopes |
Which microscope is an excellent way to observe living cells? | Phase-Contrast Microscope |
Which microscope exposes a specimen to UV, violet or blue light? | Fluorescence Microscope |
In the Fluorescence Microscope, specimens are usually stained with ____ | Fluorochromes |
What shows a bright image of the object resulting from the fluorescent light emitted by the speciman? | Fluorescence Microscope |
The Differential Interference Microscope creates images by detecting ________ and _____ of different parts of specimen. | Differences in refractive indices & Thickness |
The process by which internal and external structures are preserved and fixed in position is called | Fixation |
What preserves overall morphology but not internal structures (type of fixation) | Heat Fixation |
What protects the cellular substructure and morphology of larger, more delicate organisms? (type of fixation) | Chemical Fixation |
A staining process in which a single staining agent is used | Simple Staining |
A staining process that divides organisms into 2 or more separate groups depending on their reaction to the ame staining procedure | Differential Staining |
A substance that accelerates the reaction of cell structures with a dye so the cell is more intensly stained | Mordant |
A staining procedure in which the background is dark and the organism remains unstained | Negative Staining |
A staining process in which heat is used to Increase the affinity of bacterial endospores to dye; (endospores are usually resistant to simple staining procedures) | Spore Staining |
A staining process that enables the observation of thin, threadlike flagella by increasing their thickness and then staining them. | Flagella Staining |
Why are smears heat fixed prior to staining? | a)Kill Organisms b)Preserve internal structure c)Attach organism to slide D)All |
Which type of microscope is best for visualizing small morphological features w/i a cell interior? | a)Light B)Transmission Electron c)Dark d)Scanning Electron |
Transmission electron microscopy, a specimen can be spread out in a thin film w/ uranyl acetate,which doesnt penetrate the specimen. Whats this procedure? | A)Negative Staining b)Shadowing c)Freeze Etching d)Simple Staining |
Transmission electron microscopy requiers use of thin slices of a microbial specimen. What should the thickness of the specimen be? | a)20-100mm b)100-200nm C)20-100nm d).2-10nm |
Which type of microscope best reveals surface features of an organism? | a)fluorescence microscopy b)phase-contrast C)scanning elctron d)transmission electron |
As the magnification of a series of objective lenses increases, what happens to the working distance? | a)increases B)decreases c)stays same d)canot be predicted |
Gram staining procedure differentiates bacteria based on the chemical composition of which cell structure? | a_cytoplasmic membrane B)cell wall c)cytoplasm d)chromosome |
Whats the distance b/w the focal point of a lens and the center of the lens called? | a)working distance b)numerical aperture C)focal length d)parallax distance |
A microscopes able to keep objects in focus when the objective lens is changed. What term is used to describe this property? | a)equifocal B)parfocal c)optically constant d)focally constant |
Which microscope is especially useful for examining thick specimen like biofilms? | a)transmission electron b)dark-phase-contrast C)confocal scanning laser d)bright-field light |