easiest way to understand topic

2. Presented by
Hafsa Jamil

3. MICROSCOPE:
Microscope is an instrument used to observe very small objects that cannot be seen
with naked eye.
Types:
Basic types of microscope are
Compound StereomicroscopeConfocal TEM SEM

4. compound confocal stereoscopic TEM SEM
description Light illuminated, 2D
image obtained, high
magnification but low
resolution
uses laser light
that scans across
the specimen with
the aid of scanning
lenses
Light illuminated, 3D
image, used for
dissection, low
magnification
e-illuminated, 2D
view, high
magnification, high
resolution
3D image, high
magnification, high
resolution
Source of radiation Visible light Laser light Visible light electrons electrons
Nature of lenses glass Glass lenses with
dichromatic
mirrors
glass One electrostatic
lens with few
electromagnetic
lenses
One electrostatic lens
with few electromagnetic
lenses
focusing mechanical digital mechanical electrical electrical

5. History of microscope:
• Spectacles were first made in Italy in 13th century
• 1590 Hans & Zacharias created the first microscope
• 1665 Robert Hooke named word “cell” for structures he
observed in cork bar
• 1674 Leeuwenhoek improved simple microscope for
viewing biological specimens
• 1830 Joseph Jackson Lister discovered achromatic lens, which
compensated for chromatic aberration

6. • 1931 Ernst Ruska invented electron microscope(TEM)
• 1932 Frits Xernike invented phase contrast microscope for the
study of transparent biological material
• 1981 Binning & Rohrer invented scanning tunneling
microscope, 3D images were possible
• 1903 Richard Zsigmondy, ultramicroscope which allowed
observation of specimens below wavelength of light
• 1860 Ernst Abbe gave mathematical theory, Abbe’s apparatus

7. Cell:
 “a unit of biological activity delimited by a semipermeable membrane and capable
of self-reproduction in a medium free of other living systems.”
 Cell is the basic structural and functional unit of life

8. Cell organelles:
Microscopic views of different organelles are as follows:
Cell membrane Nucleus Vacuole Chloroplast Endoplasmic
reticulum
Golgi apparatus Ribosomes Lysosomes Centrioles Mitochondria

9. Conclusion:
Cells are tiny but complex bodies. It is difficult to see their
structure; more difficult to understand their molecular
composition and most difficult to find out the function of
their various components. Thus, to gain divergent types of
information regarding cell’s structure, molecular organization
and function, microscopes are used.