BIOS 242 Lab Practical Questions and answers 2024
S. marcescens - (answers)can grow aerobically and anaerobically
To prevent contamination from outside sources - (answers)why is proper aseptic
technique important?
heats it up to the point that if there was any bacteria it would be killed -
(answers)whats the point of flaming the inoculating loop?
it might kill the bacteria you are trying to retrieve - (answers)what happens if you
put the hot loop into the tube too soon?
to penetrate the agar to allow for bacteria to grow anaerobically - (answers)why do
you stab the agar?
breakout of a disease - (answers)what happens if there is a breakdown in aseptic
technique?
circular - (answers)shape of s. marcescens
circular - (answers)shape of e. coli
umbonate - (answers)elevation of s. marcescens
, limit the number of bacteria in each quadrant (isolate colonies) - (answers)why do
you streak the four quadrants?
total magnification - (answers)magnification of objective lens x magnification of
ocular lens
200x - (answers)20x objective and 10x eyepiece
750x - (answers)50x objective x 15x eyepiece
carbolfuchsin - (answers)acid fast primary stain
acid fast stain - (answers)used for organisms that don't stain well with gram due to
the waxy outer layer
increased magnification decreases field of vision - (answers)what does increasing
magnification do to field of vision?
more light is going through your slide thus making it a clearer image -
(answers)why is oil immersion necessary at 100x?
100x - (answers)when do you use oil immersion?
parfocal - (answers)means that you can change the focus (objective lens) of a
microscope without having to focus it every time
S. marcescens - (answers)can grow aerobically and anaerobically
To prevent contamination from outside sources - (answers)why is proper aseptic
technique important?
heats it up to the point that if there was any bacteria it would be killed -
(answers)whats the point of flaming the inoculating loop?
it might kill the bacteria you are trying to retrieve - (answers)what happens if you
put the hot loop into the tube too soon?
to penetrate the agar to allow for bacteria to grow anaerobically - (answers)why do
you stab the agar?
breakout of a disease - (answers)what happens if there is a breakdown in aseptic
technique?
circular - (answers)shape of s. marcescens
circular - (answers)shape of e. coli
umbonate - (answers)elevation of s. marcescens
, limit the number of bacteria in each quadrant (isolate colonies) - (answers)why do
you streak the four quadrants?
total magnification - (answers)magnification of objective lens x magnification of
ocular lens
200x - (answers)20x objective and 10x eyepiece
750x - (answers)50x objective x 15x eyepiece
carbolfuchsin - (answers)acid fast primary stain
acid fast stain - (answers)used for organisms that don't stain well with gram due to
the waxy outer layer
increased magnification decreases field of vision - (answers)what does increasing
magnification do to field of vision?
more light is going through your slide thus making it a clearer image -
(answers)why is oil immersion necessary at 100x?
100x - (answers)when do you use oil immersion?
parfocal - (answers)means that you can change the focus (objective lens) of a
microscope without having to focus it every time
