Bio1AL_Fa09_lab2_prelab -...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Micropipetter,
Microscope
and
Cells
Pre‐lab.

Due
at
the
start
of
lab.


 (Pages
11­44
in
the
lab
manual)
 
 Name

 
 
 
 
 

GSI
&
Sect
#

 
 
 
 
 
Station
#
 
 
 1)

What
should
you
do
if
the
fire
alarm
sounds
while
you
are
in
a
biology
lab?
 
 
 
 2)

What
is
the
predicted
weight
of
100
microliters
of
de‐ionized
water?


 
 
(include
units) 
 
 3)

A
student
weighs
10
different
samples
with
their
P‐200
micropippetter
set
to
100
microliters.

The
values
are:
 0.105
g,
0.104
g,
0.104
g,
0.102
g,
0.101
g,

0.101
g
,
0.100
g,
0.099
g,
0.099
g,
and
0.098
g.
 

 mean
=
______________
g
(Note
the
use
of
units!)
 
 
 4)

Calculate
the
number
of
water
molecules
represented
by
the
mean
value
in
number
3.

Show
your
work.
 
 
 #
of
water
molecules
=
______________
 
 
 5)

Diagram
the
window
for
withdrawing
15
µl
of
a
solution
with
the
P20
micropipettor.
 
 
 
 6)

Where
do
you
dispose
of
used
pipette
tips?
 
 
 
 7)

Why
do
you
want
to
set
critical
illumination
for
each
specimen
examined?
 
 
 
 8)

To
the
right
make
a
small
sketch
of
a
 compound
microscope
like
the
one
shown
on
 page
20
(Fig.
4).

Label:
on/off
switch,
 objective

 lenses,
stage,
focus
knobs
and
the
condenser.
 
 
 
 9)

Outline
the
correct
use
of
the
microscope,
from
specimen
until
critical
illumination
has
been
achieved
in
detail
 (especially
the
steps
that
involve
the
field
and
aperture
diaphragms).

The
first
few
steps
are
provided
(Hint:
this
 question
could
be
a
quiz
question!).

Don’t
just
copy
the
lab
manual
but
instead
think
about
the
steps!!
 
 For
example
the
reason
you
do
not
use
the
coarse
focus
knob
with
medium
to
high
power
objectives
is
because
of
 the
limited
working
distance
(the
distance
between
the
objective
lens
and
the
slide).
 a)
 Turn
the
switch
off,
set
the
lamp
intensity
to
the
lowest
setting
(1),
and
plug
in
the
microscope.
 b)
 Using
the
condenser
adjustment
knobs,
raise
the
condenser
to
its
uppermost
position.
 c)
 Use
the
coarse
focus
knob
to
lower
the
stage
to
its
lowest
point.
 d)
 Using
lens
paper,
clean
the
objective
and
ocular
lenses.
 
 
 
 
 
 Continued
on
the
Backside
 A11
–
Fall
2009
 10)

What
solution
do
you
add
to
your
slides
to
slow
down
protists?
 
 
 11)

How
do
you
make
a
wet
mount
of
Volvox?

You
want
to
avoid
bubbles.
 
 
 12)

In
the
space
to
the
right,
make
a
drawing
of
 any
common
object
that
is
greater
than
15
cm
in
 size.

Include
a
title,
appropriate
labels,
details
 and
a
scale
bar
(use
convenient,
round
 numbers).
Drawing
guidelines
are
on
page
19.

 Note
that
you
cannot
draw
this
large
object
to
 actual
dimensions
and
must
shrink
the
object.

 Thus
the
scale
bar
is
required.

This
is
true
for
 your
microscope
drawings,
but
in
reverse,
you
 will
make
drawings
much
large
than
actual
size.

 
 13)

Answer
the
following
questions
for
each
figure.

The
lines
are
100
micrometers
apart.

The
measuring
device
 is
called
a
micrometer
but
a
"ruler"
may
be
a
more
useful
term.

This
avoids
the
distinction
between
distances
 measured
in
micrometers,
versus
the
measuring
device
known
as
a
micrometer.
 For
each
figure
(include
units):
 
 a)

How
wide
is
the
field
of
view?
 
 b)

How
many
divisions,
on
the
“ruler”,
fit
into
100
micrometers?
 
 c)

What
is
the
distance
that
each
“ruler”
division
represents?
 
 14)

The
image
of
Trichonympha
(from
figure
20a
on
page
40)
is
shown
below
but
this
represents
only
one
 viewing
angle.

When
you
examine
your
slide
it
could
potentially
be
in
any
angle
(and
moving).

Try
to
predict
 what
it
would
look
like
from
a
different
viewpoint.

In
this
case,
imagine
you
are
at
the
lower
right
edge
looking
 directly
onto
the
organism
(about
a
45°angle,
as
shown
by
the
arrow).

Make
a
drawing
of
how
you
think
it
would
 look
from
this
perspective.

The
purpose
of
this
exercise
is
to
have
you
realize
that
specimens
can
be
in
any
 particular
orientation,
not
just
the
one
that
is
drawn
in
the
lab
manual.

Check
out
your
prediction
in
lab!
 
 
 
 
 
 
 
 
 Your
Drawing:
 A12
–
Fall
2009
 ...
View Full Document

Ask a homework question - tutors are online