Grade 10 The Cell : Basic Units of Life
Life Sciences
History of Microscopy
YEAR Name Country of origin Inventions / contributions
First simple microscope –
1590 Zacharias + Hans Jansen Netherlands tube with lenses that
magnified objects up to 10x
Microscope with focusing
1609 Galileo Galilei Italy
device
Studied cork under
1665 Robert Hooke England microscope – observed
‘cells’
Father of microscopy –
developed microscopes
1674 Antonie van Leeuwenhoek Netherlands with lenses that magnify up
to 270x + first person to
describe bacteria
Page | 1
,Grade 10 The Cell : Basic Units of Life
Theodor Schwann, Matthias
1839 Germany Formulated the cell theory
Schleiden + Rudolf Virchow
1931 Max Knott + Ernst Ruska Germany Electron Microscope
Microscope Characteristic + Function
Parts
eyepiece ( ocular consists of the set of lenses closest to the eye for magnification
)
coarse moves the microscope tube / stage using large movements to bring the specimen
adjustment knob clearly into focus
fine adjustment moves the microscope tube / stage for a precise + final adjustment or focus
knob
arm handle used to carry the microscope + to which the microscope tube, adjustment
knobs and stage are attached
hinge enables the arm to be moved to different angles
base bottom of the microscope + keeps it stable
light source attached to the base + provides light that sines through the opening in the stage, as
well as through the mounted specimen, up to the eye
iris diaphragm opening in the condenser – a small lever is used to regulate the amount of light that
shines on the specimen
condenser concentrates light rays from the light source onto the specimen
stage flat surface with an opening through which light shines + on which the specimen
slide is placed for study
clips / clamps hold the specimen slide in position on the stage
objectives usually three objectives with different magnifications that are attached to the
nosepiece, each having a set of lenses that magnifies the image ( 4x, 10x and 40x )
nosepiece holds the objectives + can be rotated to focus the different objectives on the
specimen
microscope tube holds the eyepiece in position + connects it to the objectives
Functions of the Parts of a
Light Microscope
Preparing a Wet Mount
Microscope Slide : rectangular glass plate on which the specimen is placed for study
Mounting Medium : the drop of water / other liquid that the specimen is placed in
* sometimes used to stain the cells
Cover Slip : thin, square glass plate that is placed on top of the specimen to
cover it
* prevents the objective lens from coming into contact with the mounting medium, keeps
the specimen in position + reduces light refraction
Page | 2
,Grade 10 The Cell : Basic Units of Life
place the cover slip @ an angle of 45⁰
keep in position with dissecting needle
no air bubbles
Calculating Total
Magnification
Total Magnification = mag. of eyepiece lens × mag. of objective lens
Actual Size = measured length of specimen ( mm) × length on scale ( μm ) /
measured length of scale ( mm)
Estimated Size ( FOV ) = how many specimens fit across diameter * diameter of FOV ( μm )
Page | 3
, Grade 10 The Cell : Basic Units of Life
Microscope
Structure of a light
10 x
40 x 4x
10 x
Microscope
There are two types of microscopes :
- light microscopes
- electron microscopes
Light Microscope
light penetrates from below
magnification up to 2000 x
glass lenses
relatively cheap as a scientific instrument
Page | 4
Life Sciences
History of Microscopy
YEAR Name Country of origin Inventions / contributions
First simple microscope –
1590 Zacharias + Hans Jansen Netherlands tube with lenses that
magnified objects up to 10x
Microscope with focusing
1609 Galileo Galilei Italy
device
Studied cork under
1665 Robert Hooke England microscope – observed
‘cells’
Father of microscopy –
developed microscopes
1674 Antonie van Leeuwenhoek Netherlands with lenses that magnify up
to 270x + first person to
describe bacteria
Page | 1
,Grade 10 The Cell : Basic Units of Life
Theodor Schwann, Matthias
1839 Germany Formulated the cell theory
Schleiden + Rudolf Virchow
1931 Max Knott + Ernst Ruska Germany Electron Microscope
Microscope Characteristic + Function
Parts
eyepiece ( ocular consists of the set of lenses closest to the eye for magnification
)
coarse moves the microscope tube / stage using large movements to bring the specimen
adjustment knob clearly into focus
fine adjustment moves the microscope tube / stage for a precise + final adjustment or focus
knob
arm handle used to carry the microscope + to which the microscope tube, adjustment
knobs and stage are attached
hinge enables the arm to be moved to different angles
base bottom of the microscope + keeps it stable
light source attached to the base + provides light that sines through the opening in the stage, as
well as through the mounted specimen, up to the eye
iris diaphragm opening in the condenser – a small lever is used to regulate the amount of light that
shines on the specimen
condenser concentrates light rays from the light source onto the specimen
stage flat surface with an opening through which light shines + on which the specimen
slide is placed for study
clips / clamps hold the specimen slide in position on the stage
objectives usually three objectives with different magnifications that are attached to the
nosepiece, each having a set of lenses that magnifies the image ( 4x, 10x and 40x )
nosepiece holds the objectives + can be rotated to focus the different objectives on the
specimen
microscope tube holds the eyepiece in position + connects it to the objectives
Functions of the Parts of a
Light Microscope
Preparing a Wet Mount
Microscope Slide : rectangular glass plate on which the specimen is placed for study
Mounting Medium : the drop of water / other liquid that the specimen is placed in
* sometimes used to stain the cells
Cover Slip : thin, square glass plate that is placed on top of the specimen to
cover it
* prevents the objective lens from coming into contact with the mounting medium, keeps
the specimen in position + reduces light refraction
Page | 2
,Grade 10 The Cell : Basic Units of Life
place the cover slip @ an angle of 45⁰
keep in position with dissecting needle
no air bubbles
Calculating Total
Magnification
Total Magnification = mag. of eyepiece lens × mag. of objective lens
Actual Size = measured length of specimen ( mm) × length on scale ( μm ) /
measured length of scale ( mm)
Estimated Size ( FOV ) = how many specimens fit across diameter * diameter of FOV ( μm )
Page | 3
, Grade 10 The Cell : Basic Units of Life
Microscope
Structure of a light
10 x
40 x 4x
10 x
Microscope
There are two types of microscopes :
- light microscopes
- electron microscopes
Light Microscope
light penetrates from below
magnification up to 2000 x
glass lenses
relatively cheap as a scientific instrument
Page | 4
