BIOS 242 Lab Practical New Exam 100% Verified
S. marcescens - ANSWER can grow aerobically and anaerobically
To prevent contamination from outside sources - ANSWER why is proper aseptic
technique important?
heats it up to the point that if there was any bacteria it would be killed - ANSWER whats
the point of flaming the inoculating loop?
it may kill the bacteria you are trying to retrieve - ANSWER what happens if you put the
hot loop into the tube too soon?
to penetrate the agar to allow for bacteria to grow anaerobically - ANSWER why do you
stab the agar?
breakout of a disease - ANSWER what happens if there is a breakdown in aseptic
technique?
circular - ANSWER shape of s. marcescens
circular - ANSWER shape of e. coli
umbonate - ANSWER elevation of s. marcescens
to limit the number of bacteria in each quadrant (to isolate colonies) - ANSWER why do
you streak the four quadrants?
, total magnification - ANSWER magnification of objective lens x magnification of ocular
lens
200x - ANSWER 20x objective and 10x eyepiece
750x - ANSWER 50x objective x 15x eyepiece
carbolfuchsin - ANSWER acid fast primary stain
acid fast stain - ANSWER used for organisms that don't stain well with gram due to the
waxy outer layer
increased magnification decreases field of vision - ANSWER what does increasing
magnification do to field of vision?
more light is going through your slide thus making it a clearer image - ANSWER why is
oil immersion necessary at 100x?
100x - ANSWER when do you use oil immersion?
parfocal - ANSWER refers to being able to change the focus (objective lens) of a
microscope without having to focus it every time
light under the stage or the iris diaphragm - ANSWER how do you change the light
reaching the ocular lens?
iris diaphragm - ANSWER controls the amount of light that is passing through (the larger
the hole the more light)
protozoa - ANSWER single celled
S. marcescens - ANSWER can grow aerobically and anaerobically
To prevent contamination from outside sources - ANSWER why is proper aseptic
technique important?
heats it up to the point that if there was any bacteria it would be killed - ANSWER whats
the point of flaming the inoculating loop?
it may kill the bacteria you are trying to retrieve - ANSWER what happens if you put the
hot loop into the tube too soon?
to penetrate the agar to allow for bacteria to grow anaerobically - ANSWER why do you
stab the agar?
breakout of a disease - ANSWER what happens if there is a breakdown in aseptic
technique?
circular - ANSWER shape of s. marcescens
circular - ANSWER shape of e. coli
umbonate - ANSWER elevation of s. marcescens
to limit the number of bacteria in each quadrant (to isolate colonies) - ANSWER why do
you streak the four quadrants?
, total magnification - ANSWER magnification of objective lens x magnification of ocular
lens
200x - ANSWER 20x objective and 10x eyepiece
750x - ANSWER 50x objective x 15x eyepiece
carbolfuchsin - ANSWER acid fast primary stain
acid fast stain - ANSWER used for organisms that don't stain well with gram due to the
waxy outer layer
increased magnification decreases field of vision - ANSWER what does increasing
magnification do to field of vision?
more light is going through your slide thus making it a clearer image - ANSWER why is
oil immersion necessary at 100x?
100x - ANSWER when do you use oil immersion?
parfocal - ANSWER refers to being able to change the focus (objective lens) of a
microscope without having to focus it every time
light under the stage or the iris diaphragm - ANSWER how do you change the light
reaching the ocular lens?
iris diaphragm - ANSWER controls the amount of light that is passing through (the larger
the hole the more light)
protozoa - ANSWER single celled
