Microbiology Lab Exam I

The skin is generally a(n) inhospitable hospitable( inhospitable, hospitable ) environment for most microorganisms.

More bacteria are found in moist areas, such as the armpit arms/legs( armpit, arms/legs ), than on the dry surfaces of the arms/legs armpit( arms/legs, armpit ).

The significance of bacteria as etiological agents was documented by Robert Koch Louis Pasteur Francis Crick( Robert Koch, Louis Pasteur, Francis Crick ) in 1876 1492 1926 1776( 1876, 1492, 1926, 1776 ).

Handwashing is generally considered the most least( most, least ) important procedure for stopping infections and the spread of germs, but excessive handwashing can actually be detrimental beneficial( detrimental, beneficial ) effects.

Basic dyes are positively negatively( positively, negatively ) charged, containing cationic anionic( cationic, anionic ) chromophores. Because the bacterial cells are slightly negatively positively( negatively, positively ) charged, there is an attraction between the positive negative( positive, negative ) dye and the negative positive( negative, positive ) cell.

Acidic dyes are negatively positively( negatively, positively ) charged, containing anionic cationic( anionic, cationic ) chromophores, and do not stain bacterial cells.

Aseptic Septic( Aseptic, Septic ): without contamination
Septic Aseptic( Septic, Aseptic ): without any microbe growth

Tools used for inoculation must be sterile aseptic( sterile, aseptic ), but the inoculation itself must be carried out by aseptic sterile( aseptic, sterile ) technique.

Petri dishes should be labeled on the bottom top( bottom, top ), and stored agar side up down( up, down ).

The best way to attain isolated colonies on a petri dish is by using the four three two one( four, three, two, one )-way streak technique.

Gram staining causes gram-positive cells with a thick thin( thick, thin ) peptidoglycan layer to stain blue to purple red to pink( blue to purple, red to pink ) and gram-negative cells with a thin thick( thin, thick ) peptidoglycan layer to stain red to pink blue to purple( red to pink, blue to purple ).

An endospore is structurally and chemically more less( more, less ) complex than the vegetative cell it comes from. Externally, there are more fewer( more, fewer ) layers.

A chemically-defined (synthetic undefined( synthetic, undefined )) medium is one in which the exact chemical composition is is not( is, is not ) known. A complex (undefined synthetic( undefined, synthetic )) medium is one in which the exact chemical constitution of the medium is not is( is not, is ) known.