Safety considerations
solutions are irritants.
spectacles (and gloves if available) as some staining
a scalpel and store it safely when not in use.
care when using
Wear safety
Wear safety specta«
.Take
.Report broken glass
to the teacher.
on the
to avoid breaking slides.
microscope
Take care with coarse adjustments when
hot
using a microscope.
lens becoming very
Beware ofthe
Recording data
draw
lens in the space below. You may choose to
what you observe through the microscope
of
Sketch diagram
should label your diagram
be many hundred cells in your field of view. You
one cell, as there may
than
more
skills learnt in Chapter 1 to guide you.
the
a
and use
drawing
Onion
Magnification: ...
Magnification:...
Handling data
2
that you drew
of eyepiece
what was the total magnification for the specimen
of objective lens x magnification
magnification
the equation: Total magnification =
E
lens
Total magnification =.
Analysls
3
observed through
Structures of the plant cell that you
.
your light microscope
disandt.
n
w
a
,
Cel
stund
ionkt
i3
nuclas
, Uhere
ColLs
Cautolc
Calthdia
VaCwolts.
*'***
State the structures of an onion cell that you cannot see using a light
....
microscope.
.
sc.As,.MAC.Q
chuardae
di
.
*****..
Evaluatlon
5
Why was it important to use only a, single layer of
thct he
onion cells for your specimen?
.
What was the
purpose of staining the plant cells?
(0 MoRe the
mor
VISI ble
skavduts
Date:
tcad
invesl
developed during Practical investigation 2.1 to prepare and observe human cheek ceils.
microscopeskills d e v e l o p e
okes them more difficult to see under a light microscope but you will see them at
cells r
cheek
in this investigation.
t u r eof
Merem
magihcationsin
wTN
ent
Disposable gloves
Microscope slide
Cover ship
Mounted needle
Staining solution
L i g h tm i c r o s c o p e
Cottonbud
(iodine or methylene blue)
Disinfectant solution
Soletyspectacles
cheek cells. You should use
Vtrteacher will demonstrate how to take a sample of human
and your knowledge from the previous investigation
the subtle differences in preparing
to plan a method in the space below. Take care to ob
this slide.
Sid
.
*****
****
bud
Uhe
slug
this demonstration
.
JA..L
entiggnd
Al..
IntnuXMA
olue.gAnA
****°''*
endYEX(2%
°**°°**°°*
***
*'******
*
an
Salety considerations
immediately after
disinfectant solution
ace cotton buds into the
Wear safety spectacles and gloves at all times
Report broken glass to the teacher immediately.
N E Care
when using a light
microscope as the
ate tve
be met
different criteria that should
dul4no
...O
very not.
lens can become
ecording data
when drawing
use.
a
biological spece
di
ine
hpkchy
d dw
nAineca ppe
.
31
Noke
don
Makor
nclude
Sketch a diagram of what you
observe through the microscope lens in the s n se
below, a t
on both doccasidifoeree
n
label your diagrams and state the magnification used
magnifications. You should
Magnification:..
Magnification
*'*'"'"****
alysis
Complete the following table by ticking the boxes to show which organelles are visible whenusing
light microscope.
Humancheekcell
organele
Function
nucleus
brin e
cell wall
cell membrane
cytoplasm
ribosomes
chloroplasts
Give the name of
the organelle that is the site of aerobic
MtooNdsi.
*****'***
respiration.
*
.
.
..
'
**'****
''"
Evaluation
How cOuld you view
parts of organelles that wEre nol
Visible using a lighl
*********'****'********"'** ****
7
Explain why the cotton buds were placed into disinfectant or
cell sample.
microscope?
. ....
*'*****'
sterilisina
******
'
fluid after
being used to collect the
******'********'********* n e l i o
32