Week 2 - BIOS 242 EXAM
QUESTIONS AND VERIFIED
CORRECT ANSWERS LATEST
2026-2027
scanning tunnel microscopes - CORRECT ANSWER-passes a metal probe, sharpened to end in a
single atom, back and forth across and slightly above a specimen which measures electron flow
to and from the probe (creates a 3D image)
atomic force microscope - CORRECT ANSWER-uses a pointed probe, but it traverses the tip of
the probe lightly on the surface of the specimen rather than at a distance (deflection of laser
beam translated into atomic topography)
scanning tunneling microscope and atomic force microscopes - CORRECT ANSWER-what are the
2 types of probe microscopes?
staining - CORRECT ANSWER-Most microorganisms are difficult to view by bright-field
microscopy therefore coloring specimens increases contrast and resolution
heat fixation - CORRECT ANSWER-slide is gently headed by passing above a flame which kills
everything but the microorganisms are attached to the slide now
acidic dyes - CORRECT ANSWER-stain alkaline structures
, basic dyes - CORRECT ANSWER-stain acidic structures (more common since most cells are
negatively charged)
simple stains - CORRECT ANSWER-composed of single basic dye (always one color) and used to
determine the size, shape, and arrangement of cells
crystal violet, safranin, and methylene blue - CORRECT ANSWER-three examples of simple stains
differential stains - CORRECT ANSWER-use more than one dye so that you can distinguish
different cells, chemicals, or structures
gram stain, acid-fast, endospore, and histological stains - CORRECT ANSWER-four examples of
differential stains
special stains - CORRECT ANSWER-simple stains used to identify specific microbial structures
endospore stain - CORRECT ANSWER-which stain appears green
acid-fast stain - CORRECT ANSWER-pink to red for acid-fast cells and blue for non-acid cells
staining for electron microscopy - CORRECT ANSWER-chemicals containing heavy metals
(usually lead or carbon) which gives the sample one uniform charge
taxonomy - CORRECT ANSWER-consists of classification, nomenclature, and identification,
organizes large amounts of info about organisms, and makes predictions based on knowledge of
similar organisms
Carolus Linnaeus - CORRECT ANSWER-classified organisms based on common characteristics
and grouped organisms that can successfully interbreed
QUESTIONS AND VERIFIED
CORRECT ANSWERS LATEST
2026-2027
scanning tunnel microscopes - CORRECT ANSWER-passes a metal probe, sharpened to end in a
single atom, back and forth across and slightly above a specimen which measures electron flow
to and from the probe (creates a 3D image)
atomic force microscope - CORRECT ANSWER-uses a pointed probe, but it traverses the tip of
the probe lightly on the surface of the specimen rather than at a distance (deflection of laser
beam translated into atomic topography)
scanning tunneling microscope and atomic force microscopes - CORRECT ANSWER-what are the
2 types of probe microscopes?
staining - CORRECT ANSWER-Most microorganisms are difficult to view by bright-field
microscopy therefore coloring specimens increases contrast and resolution
heat fixation - CORRECT ANSWER-slide is gently headed by passing above a flame which kills
everything but the microorganisms are attached to the slide now
acidic dyes - CORRECT ANSWER-stain alkaline structures
, basic dyes - CORRECT ANSWER-stain acidic structures (more common since most cells are
negatively charged)
simple stains - CORRECT ANSWER-composed of single basic dye (always one color) and used to
determine the size, shape, and arrangement of cells
crystal violet, safranin, and methylene blue - CORRECT ANSWER-three examples of simple stains
differential stains - CORRECT ANSWER-use more than one dye so that you can distinguish
different cells, chemicals, or structures
gram stain, acid-fast, endospore, and histological stains - CORRECT ANSWER-four examples of
differential stains
special stains - CORRECT ANSWER-simple stains used to identify specific microbial structures
endospore stain - CORRECT ANSWER-which stain appears green
acid-fast stain - CORRECT ANSWER-pink to red for acid-fast cells and blue for non-acid cells
staining for electron microscopy - CORRECT ANSWER-chemicals containing heavy metals
(usually lead or carbon) which gives the sample one uniform charge
taxonomy - CORRECT ANSWER-consists of classification, nomenclature, and identification,
organizes large amounts of info about organisms, and makes predictions based on knowledge of
similar organisms
Carolus Linnaeus - CORRECT ANSWER-classified organisms based on common characteristics
and grouped organisms that can successfully interbreed
