- Microscopy allows observation of objects less than 100 micrometers, opening up the microscopic world. The invention of the light microscope in the 16th century was pivotal. - Microscopes are classified as light or electron microscopes. Light microscopes use visible light and have limitations based on wavelength, while electron microscopes have much higher resolving power. - Various specialized microscopy techniques exist like fluorescence microscopy, which uses ultraviolet light and optical filters to observe fluorescent materials in cells and tissues.

2. Microscopy
• ‘Human eye is not capable to observe the objects that
are less than 100µ.
• Microscope is important tool for a cell biologist.
• Invention of light microscope in 16th century is the
most important single contribution.
• Microscope opened the universe of microorganisms.
• It also enabled us to study structure cells and tissues in
ultra details.
• Fields of biology viz. embryology, histology, mycology,
bacteriology, etc. owe their existence due to
microscope.
• Based on source of microscopes are classified Light
Microscope and Electron Microscope

9. Resolving power
Numerical aperture(NA)
determines the resolving
power of an objective
Total resolution of entire
microscope is also dependent
upon NA of the substage
condenser.
Higher NA of the total
system, the better the
resolution.
Resolution (r) =
1.22λ/(NA(obj) + NA(cond)

12. Simple microscope

27. • Fluorescence is a characteristic property of certain cell materials and
some organic dyes.
• Phenomenon of fluorescence occurs in certain kinds of small
organic molecules that can electronically excite.
• Fluorescence takes place when ultraviolet (invisible) light gets
converted into visible light of different wavelengths.
• Depending on wavelength emitted the detection of materials is
carried out.
• This microscope is similar to light microscope in construction.
However, it uses ultraviolet as a source of illumination and it is fitted
with a pair of adaptors called complimentary filters.
• This microscopy is used for observing fluorescence in cell and
tissues.

35. Typical Electron Microscope

36. Transmission electron microscope
(TEM)
Scanning electron microscope
(SEM)
Scanning transmission electron
microscope (STEM)

44. For SEM: a fine probe (beam spot) is formed by condenser lens
and its size determines the resolution (this differs from the TEM
which is diffraction limited)

53. 1

54. Pollen
characteristics
B. diffusa B. erecta B. repanda T.portulacastrum
Shape Spheroidal Spheroidal Spheroidal Triangular
Porate/colpate Panporate Panporate Panporate Colpate
Diameter (µ) 76.11
(55.0-92.0)
72.29
(52.0-90.0)
112.77
(101-135.0)
55.10
(45.0-90.0)
Wall thickness (µ) 4.80
(2.5-9.0)
4.40
(2.25-6.0)
7.51
(6.0-10.7)
1.92
(1.0-3.0)
Interporal distance
(µ)
13.2
(8.5-14.5)
16.77
(15.1-25.0)
23.85
(20.0-30.0)
-
Pore/colpus diameter
(µ)
6.42
(3.5-10.0)
4.27
(3.0-6.0)
8.88
(5.7-12.0)
52.5 (41.0-84.5)
X 10.5 (8.0-12.2)
Ectine Spinulate Spinulate Spinulate Granulate
Ornamentation Foveolate Foveolate Foveolate Punctate

55. Identification keys are
prepared on the basis of
pollen size.

56. Identification keys
are prepared on the
basis of trichome
types and sizes of
trichomes.

59. Stem Stomata
Crystals

60. • Cytological evidences is used for
distinguishing taxa; to determine the
origin of groups and to understand the
evolutionary history of related taxa.
• Chromosome homology studies are
used in knowing the degree of genetic
relationship.
• It is also used for studying
nanoparticles related cytotoxicity.
Some evidential characteristics are:
(i) Chromosome number, structure, type,
(ii) Chromosome meiotic behaviour,
(iii) Ploidy level and type, and
(iv) Chromosome aberration.

61. • Proper microscope use is one of the
most important skills for pathologist.
• Microscopes are important in
identifying causal organisms in
diseases.
• Although microscopes often are
introduced to students however they
are not knowing much details about
microscopy.