MCB 2004 FINAL EXAM QUESTIONS WITH VERIFIED
ANSWERS
What is the decolorizer in a Gram stain? - Answers - alcohol (ethanol)
What color are gram-positive cells after staining - Answers - purple
Adding iodine during a Gram stain stains gram-negative cells pink - Answers - False
Fungi can be stained and viewed under a microscope - Answers - True
Name one species of gram-positive bacteria - Answers - Staphylococcus aureus
Streptococcus pyogenes
Streptococcus epidermidis
Molds and yeast are both types of fungi - Answers - True
Fungi reproduce using spores - Answers - True
Fungi are prokaryotes - Answers - False
Why do cells have to be stained before viewing under a microscope? - Answers - They
are naturally colorless, so they need to be stained to be visualized against the
background.
Hydrogen peroxide will be added to two samples in lab to see if bubbles form this test
will check for the presence of what enzyme - Answers - Catalase
Name one species of Gram negative bacteria - Answers - E. Coli
Growing bacteria on sheep blood agar test the species ability to do what - Answers -
Produce toxins that digest (hemolyze) red blood cells
Which type of bacteria are we trying to differentiate/identify using sheep blood agar and
mannitol salt agar - Answers - Gram positive
When we inoculate bacteria on a starch plate, we are testing it's ability to metabolize
what substance - Answers - Starch
Growing bacteria on sheep blood agar test the species ability to do what - Answers -
Hemolyze red blood cells (digest them)
ANSWERS
What is the decolorizer in a Gram stain? - Answers - alcohol (ethanol)
What color are gram-positive cells after staining - Answers - purple
Adding iodine during a Gram stain stains gram-negative cells pink - Answers - False
Fungi can be stained and viewed under a microscope - Answers - True
Name one species of gram-positive bacteria - Answers - Staphylococcus aureus
Streptococcus pyogenes
Streptococcus epidermidis
Molds and yeast are both types of fungi - Answers - True
Fungi reproduce using spores - Answers - True
Fungi are prokaryotes - Answers - False
Why do cells have to be stained before viewing under a microscope? - Answers - They
are naturally colorless, so they need to be stained to be visualized against the
background.
Hydrogen peroxide will be added to two samples in lab to see if bubbles form this test
will check for the presence of what enzyme - Answers - Catalase
Name one species of Gram negative bacteria - Answers - E. Coli
Growing bacteria on sheep blood agar test the species ability to do what - Answers -
Produce toxins that digest (hemolyze) red blood cells
Which type of bacteria are we trying to differentiate/identify using sheep blood agar and
mannitol salt agar - Answers - Gram positive
When we inoculate bacteria on a starch plate, we are testing it's ability to metabolize
what substance - Answers - Starch
Growing bacteria on sheep blood agar test the species ability to do what - Answers -
Hemolyze red blood cells (digest them)
