Biol 251 First Exam

Front 1

Brightfield

Back 1

Uses visible light as a source of illumination; cannot resolve structures smaller than about 0.2 um; specimen appears against a bright background. Inexpensive and easy to use.

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Darkfield

Back 2

Uses a special condenser with an opaque disk that blocks light from entering the objective lens directly; light reflected by specimen enters the objective lens, and the specimen appears light against a black background.

Front 3

Phase-contrast

Back 3

Uses a special condenser containing an annular (ring-shaped) diaphragm. The diaphragm allows direct light to pass through the condenser, focusing light on the specimen and a diffraction plate in the objective lens. No staining required.

Front 4

Flourescence

Back 4

Uses an ultraviolet or near-ultraviolet source of illumination that causes fluorescent compounds (green-colored) in a specimen to emit light.

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Confocal

Back 5

Uses a single photon to illuminate one plane of a specimen at a time.

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Two-Photon

Back 6

Uses two photons to illuminate a specimen

Front 7

Scanning Acoustic

Back 7

Uses a sound wave of specific frequency that travels through the specimen with a portion being reflected when it hits an interface within the material.

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Transmission Electron

Back 8

Uses a beam of electrons instead of light; electrons pass through the specimen; because of the shorter wavelength of electrons, structures smaller than 0.2 um can be resolved. Two-dimensional image.

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Scanning Electron

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Three-dimensional.

Front 10

Sarr II (pelagibacter ubique)

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The most common microbe in the world. Gram negative. Small genome. Name means: ocean, bacterium, unique. In water samples

Front 11

What are the 3 domains?

Back 11

Bacteria, Archaea, Eukarya

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What are the Eukaryotes?

Back 12

Fungi, protists, protozoa, algae, animals

Front 13

Viruses

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Non-cellular. Cannot reproduce on own, just parasites. Associated with all kingdoms. Host-specific

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Prokaryotes

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No true nucleus. Bacteria and archea. 1-10 microns.

Front 15

Eukaryotes

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membrane bound organeles. Protozoa, fungi, algae, multicellular organisms. Typical size 10-100 microns.

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Linnaeus

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Came up with technique of classifying organisms. Did not include domain. Capitalized genus, lower cased species.

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Hooke

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Named cells. Looked at cork under microscope. Cells used to be called genules.

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Antony van Leeuwenhoek

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Made microscopes. Each microscope devoted to specific microbe. Called them animalcules. Published his work.

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Streptococcus mutans

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Relevant to pre-dental. Gram positive cocci. Part of normal flora. Takes sucrose and breaks it down to glucose + fructose. Makes chains of glucose (dextrin) and leads to break down of teeth.

Front 20

Redi

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Against spontaneous generation. Tried to prove by sealing jars. Maggots appeared only when flies were able to lay eggs.

Front 21

Needham

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For spontaneous generation. Heated nutrient fluids, but found bacteria after cooling.