distance between two corresponding parts of a wave
apparant increase in size of an object. Things are magnified when a beam of radiation bends as it passes through a lens.
Also called resolving power. Ability to distinguish between objects that are close together. The better the resolution the better the ability to distinguish two objects that are close to one another.
Differences in intensity between two objects or between and object and its background.
Bright field microscope (Light scope)
Background (field) is illuminated, but specimen is not
Dark field microscope (Light scope)
Specimen is made to appear light against a dark background
Phase microscope (Light scope)
Use alignment or misalignment of light waves to achieve the desired contrast between a living specimen and its background
Flourescent microscope (Light scope)
Use invisible ultraviolet light to cause specimens to radiate visible light (called fluorescence)
Confocal microscope (Light scope)
Use lasers to illuminate fluorescent chemicals in a thin plane of a specimen
Molecules absorb energy from invisible radiation and then radiate it back as longer visible wavelengths
Transmission electron microscope (Electron scope)
TEM Generates a beam of electrons that produce an image on a fluorescent screen. Can only examine dead organisms
Scanning electron microscope (Electron scope)
SEM uses magnetic fields within a vacuum to manipulate beams of electrons just like the TEM miscroscope does, however rather than passing the electrons through a specimen, the SEM focuses them back and forth across the specimens surface which has been coated in platinum or gold. Can only examine dead organisms
Scanning Tunneling microscope (Probe scope)
STM passes a metallic probe, sharpened to end in a single atom back and forth acoss and slightly above the surface of specimen. Measures the flow of electrons to and from the probe and specimen. Specimen must be electrically condusive.
Atomic force microscope
AFM used same pointed probe as STM except it traverses the tip of probe lightly on the surface rathen than at a distance.
thin film of organisms on a slide
Stain alkaline structures and work best in acidic environments. (Negatively charged anionic chrmophores)
Combine with and stain acidic structures and work best under basic conditions. (Positively charged cationic chromophores)
single basic dye such as crystal violet, safranin, or methylene blue. Involve no more than soaking the smear in the dye for 30-60 seconds and then rinsing the slide with water.Used to determine size, shape, and arrangement of cells.
Use more than one dye so that different cells, chemicals, or structures can be distinguished when microscopically examined. Common types are gram stain, acid-fast stain, and endospore stain.
differentiates between two large groups of microorganisms (purple staining gram positive cells and pink staining gram negative cells)
Acid fast stain
Stains cells of the genera Mycobacterium and Nocardia. These types of cells have large amounts of waxy lipid in their cell walls so they do not readily stain with the Gram stain.
non overlapping groups in which organisms are sorted into on the bais of mutual similiarities.
Science of classifying and naming organisms
assigning organisms to taxa based on simliarties
Rules of naming organisms
Determining that and isolated individual or population belongs to a particular taxon.
Categories of similiar organisms that can successfully interbreed and produce viable offspring
Asexual organisms, populations of cells that arose from a single cell and share many stable properties and differ from other strains.