| A | B |
|---|
| scientific method | a universal approach to scientific problems |
| hypothesis | a possible explanation for an observed set of facts |
| controlled experiments | tow identical experiments are set up, and these allow researchers to isolate and test the effects of a single factor |
| variable | a single factor |
| control | the setup in which no change was made, serves as a referecne |
| theories | explanations that apply to a broad range of phenomena and that are supported by experimental evidnece |
| scientific law | a statement that describes some aspect of a phenomenon that is always true |
| SI | the metric system-- International System of Units (abbreviation) |
| light microscope | optical microscope |
| magnification | the ratio of the image size to the object size (____ing power)// the enlargement of an image |
| simple microscope | magnifying glass, one single lens |
| compound microscope | uses two lenses |
| optical system | lenses make up the ____ of a compound microscope. The two lenses are the objective and the ocular. |
| mechanical system | made up of the structural parts that hold the specimen and lenses and permit focusing of the image |
| light system | consists of a mirror and a diaphragm |
| resolution | th ability of a microsope to show two points that are close together as separate images |
| phase-contrast microscope | a special type of compound microscope that allows the details within living specimens to be seen without staining |
| steriomicroscope | the type of light microscope used in studying the external, or surface, structure of specimens |
| transmssion electron microscope | magnifies images more than 250,000 times-- uses electron beams and electromagnetic lenses |
| scanning electron microscope | uses an electron beam that has been focused to a fine point |
| centrifugation | materials of different densities suspended in a liquid can be separated from each other by this process |
| microdissection | tiny instruments are used to perform various operations on living cells |
| tissue culture | the technique of maintaining living cells or tissues in a culture medium outside the body |
| chromatography | any technique that separates different substances from each other on the basis of their chemical or physical properties |
| electrophoresis | the technique for separating substances made up of particles that have an electical charge |
| spectrophotometry | method of using light to analyze samples |
