BIO 235 Microbiology Exam 1 Questions
with Correct Answers
confocal scanning laser microscopy -uses a computerized microscope coupled with a
laser source to generate a 3D image
-computer can focus the laser on single layers of the specimen
-different layers can then be compiled for a 3D image
TEM -transmission electron microscopy
-uses ultra-thin sections of specimens
-light passes through specimen, then an electromagnetic lens, to a screen or film
-enables visualization of structures at the molecular level
-specimen must be very thin (20-60nm) and be stained with heavy-metal salts
-resolution 0.2nm
SEM -scanning election microscopy
-specimen is coated with a thing film of heavy metal (like gold)
-an electron gun produces a beam of electrons that scans the surface of a whole specimen
,-secondary electrons emitted from the specimen produce the image
-only the surface of an object is visualized
-resolution 20nm
fixing cells attaches the microbes to the surface of the slide and kills them
acidic dye chromophore is an anion (negatively charged)
basic dye chromophore is a cation (positively charged)
negative stain the process of staining the glass slide instead of the cell
gram stain -classifies bacteria into gram positive or gram negative
-gram positive bacteria tend to be killed by penicillin and detergents
-gram negative bacteria are more resistant to antibiotics
capsule -layer outside of the cell wall that neatly organized and attached firmly to the
wall
, -prevents phagocytosis
endospore -non-reproductive
-protects against temperature (heat), pH, harsh chemicals, radiation, aging, etc
-occurs in hours when growth ceases due to lack of nutrients
-sporulation cycle consists of a dormant vs. vegetative phase
-ideal for dispersal via wind, water, or animal gut
morphology -cell shape
-major morphologies: coccus, bacillus, spirillum
coccus spherical or ovoid
bacillus rod shape
spirillum spiral shape
cell arrangements -diplococci
with Correct Answers
confocal scanning laser microscopy -uses a computerized microscope coupled with a
laser source to generate a 3D image
-computer can focus the laser on single layers of the specimen
-different layers can then be compiled for a 3D image
TEM -transmission electron microscopy
-uses ultra-thin sections of specimens
-light passes through specimen, then an electromagnetic lens, to a screen or film
-enables visualization of structures at the molecular level
-specimen must be very thin (20-60nm) and be stained with heavy-metal salts
-resolution 0.2nm
SEM -scanning election microscopy
-specimen is coated with a thing film of heavy metal (like gold)
-an electron gun produces a beam of electrons that scans the surface of a whole specimen
,-secondary electrons emitted from the specimen produce the image
-only the surface of an object is visualized
-resolution 20nm
fixing cells attaches the microbes to the surface of the slide and kills them
acidic dye chromophore is an anion (negatively charged)
basic dye chromophore is a cation (positively charged)
negative stain the process of staining the glass slide instead of the cell
gram stain -classifies bacteria into gram positive or gram negative
-gram positive bacteria tend to be killed by penicillin and detergents
-gram negative bacteria are more resistant to antibiotics
capsule -layer outside of the cell wall that neatly organized and attached firmly to the
wall
, -prevents phagocytosis
endospore -non-reproductive
-protects against temperature (heat), pH, harsh chemicals, radiation, aging, etc
-occurs in hours when growth ceases due to lack of nutrients
-sporulation cycle consists of a dormant vs. vegetative phase
-ideal for dispersal via wind, water, or animal gut
morphology -cell shape
-major morphologies: coccus, bacillus, spirillum
coccus spherical or ovoid
bacillus rod shape
spirillum spiral shape
cell arrangements -diplococci
