GBBE MICROBIOLOGY CH. 3 & 4
QUESTIONS WITH 100% CORRECT
ANSWERS { GRADED A+}
Fixed - ✔✔Fixation is process by which the internal & external structures of cells
& microorganisms are preserved & fixed.
Basic Dye - ✔✔a salt in which the color is in the positive ion; used for bacterial
stains
Acidic Dye - ✔✔a salt in which the color is in the negative ion; used for negative
staining
Staining - ✔✔treating (specimens for the microscope) with a reagent or dye that
makes certain structures visible without affecting others.
Negative Stain - ✔✔a simple stain that stains the background but leaves the
bacteria unstained
, Simple Stain - ✔✔a method of staining microorganisms with a single basic dye
Mordant - ✔✔A mordant is classically defined as an ion that binds a chemical dye
and holds it down, such that the dye remains stuck on the organism. However, any
chemical that keeps a dye in place can also be considered as a mordant.
Gram Stain - ✔✔A method for the differential staining of bacteria that involves
fixing the bacterial cells to a slide and staining with crystal violet and iodine, then
washing with alcohol, and counterstaining with safranin. Results in gram-positive
bacteria retaining the purple dye and gram-negative organisms having it
decolorized so that the red counterstain shows up.
Primary Stain - ✔✔First stain applied during a differential stain procedure
Decolorizing Agent - ✔✔a solution used in the process of removing a stain
Differential Stains - ✔✔Used to distinguish between bacteria
Gram stain
Acid-fast stain
Gram-Positive - ✔✔Describing the group of bacteria that have a cell wall that is
structurally less complex and contains more peptidoglycan than the cell wall of
QUESTIONS WITH 100% CORRECT
ANSWERS { GRADED A+}
Fixed - ✔✔Fixation is process by which the internal & external structures of cells
& microorganisms are preserved & fixed.
Basic Dye - ✔✔a salt in which the color is in the positive ion; used for bacterial
stains
Acidic Dye - ✔✔a salt in which the color is in the negative ion; used for negative
staining
Staining - ✔✔treating (specimens for the microscope) with a reagent or dye that
makes certain structures visible without affecting others.
Negative Stain - ✔✔a simple stain that stains the background but leaves the
bacteria unstained
, Simple Stain - ✔✔a method of staining microorganisms with a single basic dye
Mordant - ✔✔A mordant is classically defined as an ion that binds a chemical dye
and holds it down, such that the dye remains stuck on the organism. However, any
chemical that keeps a dye in place can also be considered as a mordant.
Gram Stain - ✔✔A method for the differential staining of bacteria that involves
fixing the bacterial cells to a slide and staining with crystal violet and iodine, then
washing with alcohol, and counterstaining with safranin. Results in gram-positive
bacteria retaining the purple dye and gram-negative organisms having it
decolorized so that the red counterstain shows up.
Primary Stain - ✔✔First stain applied during a differential stain procedure
Decolorizing Agent - ✔✔a solution used in the process of removing a stain
Differential Stains - ✔✔Used to distinguish between bacteria
Gram stain
Acid-fast stain
Gram-Positive - ✔✔Describing the group of bacteria that have a cell wall that is
structurally less complex and contains more peptidoglycan than the cell wall of
