Biology Chapter 3 Flashcards

Light source (illuminator); condenser; specimen; objective lens; ocular lens.

The total magnification of an object is calculated by multiplying the magnification of the objective lens by the magnification of the ocular lens (objective lens x ocular lens).

Focuses the light onto the specimen.

<p>Controls the amount of light reaching the specimen.</p> Signup and view all the answers

<p>A thin film of material containing the microorganism is spread onto the slide. A Bunsen burner is then used to dry everything up. Stain is applied, then washed off with water. The slide is blotted with absorbent paper and is ready for examination.</p> Signup and view all the answers

<p>Before a microorganism can be stained it must be fixed (attached) to a microscope slide, which kills the microorganisms and fixes them to the slide while preserving their structure.</p> Signup and view all the answers

<p>The ability to distinguish two objects from each other in fine detail and structure.</p> Signup and view all the answers

<p>Simply how much an image is enlarged.</p> Signup and view all the answers

<p>The measure of its ability to gather light and resolve fine specimen detail at a fixed object's distance.</p> Signup and view all the answers

<p>Specimen is illuminated by light passing through an annular diaphragm. Direct light rays travel a different path that are reflected or diffracted as they pass through the specimen. These two sets of rays are combined at the eye.</p> Signup and view all the answers

<p>Examines living organisms that are invisible to the ordinary light microscope and cannot be stained or distort the image.</p> Signup and view all the answers

<p>Uses a special condenser with an opaque disk that eliminates all light in the center of the beam. Only light from the specimen reaches the objective lens, making the specimen appear light against a dark background.</p> Signup and view all the answers

<p>Specimens are first stained with fluorochromes and then viewed through a compound microscope using an ultraviolet light source.</p> Signup and view all the answers

<p>Fluorescence microscopy is used primarily in diagnostic procedures called fluorescent-antibody (FA) technique or immunofluorescence.</p> Signup and view all the answers

<p>Fluorescence results from a process that occurs when certain molecules called fluorophores absorb light. As they decay from an excited state, they emit fluorescent light.</p> Signup and view all the answers

<p>Viruses and internal structures of cells are examined by this; beams of electrons are used instead of light.</p> Signup and view all the answers

<p>Electron microscopes use electromagnetic lenses to focus a beam of electrons onto a specimen, ensuring better resolution due to shorter wavelengths.</p> Signup and view all the answers

<p>The beams of electrons are stronger than light; electron waves travel in shorter lengths with an electron resolution power of 0.2 um, about 100,000x smaller than visible light wavelengths.</p> Signup and view all the answers