|
WORKSHEET
: MICROBIOLOGY LAB PROCEDURE
1. Which type of microscope is designed to use specimens that:
a) use a radioactive dye
b) specimen must be thinly sliced and dehydrated
c) uses differences in diffraction to make
cell structures more visible
d) can create a 3D image
2. What is the name of the microscope part that:
a) controls the amount of light coming through
the stage?
b) can magnify the image 4X, 10X, 40X, or
100X?
c) moves the body tube slightly to bring
the image into sharper focus?
d) holds the objectives and can be turned
to change from one magnification to the other?
3. When comparing the sizes of microscopic objects:
a) Which of the following objects is approximately
1 micron in size?
generalized
cell // bacterium // virus // molecule
b) Which of the following objects can be
seen through a light microscope?
atom
// albumen // bacteria // virus
4. The distance between the graduations of a(n) …………………………………
micrometer
never change.
5. List two advantages a hanging-drop slide has over a typical wet mount.
6. Before staining a bacteria it must be prepared on the slide. Describe
what the following two
processes do to the bacteria on the slide.
a) smear b)
heat fixation
7. Differential stains can tell a scientist more about a bacteria than
simple or negative stains can.
a) List 2 pieces of information a scientist
can learn about bacteria by simple or negative staining.
b) List 1 additional piece of information
a scientist can learn about bacteria by differential staining.
c) The most widely used differential staining
technique is gram staining. What two groups are
formed
by gram staining?
d) What makes a negative stain different
than any other differential stain?
8. a) What is agar made of?
b) What form of agar would I use if I want to:
1)
subculture some colonies of bacteria on a surface?
2)
grow a bacteria that doesn’t like O2?
3)
grow bacteria over a large surface area?
c) Why are agar plates not used for long-term
storage of bacteria cultures?
9. a) Hospital labs use a lot of agar enriched with blood. Why is blood
agar so common in hospitals?
b) Is nutrient agar (which is the type we use
a lot at UT) an example of a(n):
enriched,
differential, or selective agar? EXPLAIN.
c) In genetic engineering it is common to add an antibiotic such as ampicillin
to agar. Is ampicillin
agar
an example of a(n): enriched, differential, or selective agar? EXPLAIN.
10. When growing cultures, scientists sometimes need to measure that growth.
a) What instrument could be used to count
the number of colonies on an agar plate?
b) How does a spectrophotometer measure
the growth of the culture?
11. a) Which type of heat would be best for sterilizing:
1)
agar 2)
a glass beaker
3)
a metal loop 4)
a tube of broth
b) Which one of the following materials
could be sterilized using both filtration and radiation?
1)
a can of vegetable soup 2)
bottle of apple juice 3)
bag of potato chips
12. a) I am a scientist trying to study a bacteria by growing several
individual colonies,
and
then making stained slides from those colonies. To do this I would pour
my
agar
into a (Petri dish / culture tube). Next I would transfer some bacterial
culture
onto my agar using a (wire loop / pipet) creating a (pour-plate / streak
plate).
Finally
I would place my prepared media into a (incubator / refrigerator).
b) I can continue my studies by using a
……………………….……
to manually count the
individual
bacteria. Sometimes the bacteria may be too numerous and I may need to
reduce
their concentration by doing a ………………………………………
before I
can
count them. If I need to keep the bacteria growing longer I can ……………………
them
by placing them into another test tube with fresh agar. Whenever I'm done
studying
the
bacteria, or using my lab equipment I should ………………………………
them
before
disposal.
13. Match the following sterilizing chemicals with their descriptions.
a) disinfectant 1)
penicillin
b) antibiotic 2)
for living surfaces
c) antiseptic 3)
bleach, ammonia
14. Which microbiology tool would I use to transfer:
a) a single colony of bacteria from a streak
plate and place that colony into an agar slant?
b) 1 ml. of bacteria from a broth to an
agar plate?
**********************************************************************************
15. Which type of electron microscope:
a) can magnify more b)
allows you to see external features such as eyes
c) glow bright colors d)
is smaller in overall size
16. a) Why do all culture vessels, whether they're bacterial tubes or
Petri dishes, have lids on them?
b) (TRUE/FALSE) Agar will hold many
different shapes once it cools inside a container
17. How often should you flame a wire loop as you are:
a) subculturing a culture from one culture
tube to another?
b) streaking bacteria across an agar plate
during a Quadrant streak?
18. a) A simple stain sticks to the bacteria, while a negative stain
sticks to the background. This
suggests that the outer cell wall of a bacteria has what charge?
b) What does the ethyl alcohol do to a Gram
negative bacteria?
c) What dye gives a Gram negative bacteria
its final color?
d) Which of the following parts of a bacteria
do you think determines whether it will be
Gram
positive or Gram negative?
CIRCLE
ONE--> (Nucleus / Cytoplasm / Cell wall / Golgi bodies / Vacuoles)
19. Do all bacteria look the same when they are growing in or on agar?
Explain.
|