2. Microorganism-
Introduction
A microorganism or microbe is a microscopic
organism, which may be a single cell or multi
cellular organism. The study of microorganisms is
called microbiology,
a subject that began with Anton van Leeuwenhoek's
discovery of microorganisms in 1675, using a
microscope of his own design.
6. Bacteria
• Bacteria are among the simplest and very
small living thing.
• They are single celled organisms and they
range from 0.2µm to 10µm
• They are found everywhere.
The types of bacteria are -
Bacteria
Bacillus Cocci Spirilla
9. Bacillus or rod-shaped bacteria
Bacillus, or rod shaped bacteria, are
one of the main forms of bacteria.
They are typically 0.5 micrometers to
1.0 micrometer in width, and from 1.0
micrometer to 4.0 micrometers in
length.
Example of bacillus include Bacillus
anthracis, the bacterium that causes
anthrax.
10. Cocci or spherical bacteria
• Coccus are spherically
shaped bacteria that
organize in several
distinct arrangements
when in groups
• They occur in
diplococcus, tetrad,
sarcina, and
staphylococcus
arrangements.
11. Spirilla or spiral bacteria
The last recognized
form of bacteria is
known as the spiral.
It occurs in three
different forms :-
Vibrio
Spirillium
Spirochete
16. 5/21/2014 1.1_Classificationofmicros
Size of Algae
• 1. Can be unicellular
(chlamydomonas) /
multicellular
(seaweeds) plants.
• 2. have / no
chlorophyll.
• 3. Size: 1 µm – 10 000
µm.
• 4. Have various
17. Algae
• They are simple plant like organisms which
contain chlorophyll.
• They can be unicellular or multicellular.
• They exist in many shapes and colors.
• They vary from 1µm to 10,000µm.
20. Protozoa
• They are animal-like, unicellular organisms.
• They can be of 5µm to 250µm.
• They are of three shapes – Round, Spherical
and Spindle shaped.
22. 5/21/2014 1.1_Classificationofmicros
Size of Viruses
• 1. Smallest microorganisms.
• 2. Visible under electron
microscope.
• 3. Different types of viruses
have different shapes.
• 4. Size: 0.0006 µm – 0.4 µm /
(6 – 400 nm)
23. Viruses
• They are the smallest of microorganisms.
• They are visible only under an electron
microscope.
• They are of 6 nm to 400 nm.
• They have no definite shape.
24. Microbes live in the water we drink, the food we eat, and the air we breathe. Right now, billions
of microbes are swimming in our digestive
systems and crawling on our skin! But don't worry, over 95% of microbes are harmless. Microbes
are single-cell organisms invisible to the eye that come in different
shapes seen only with microscopes.
25. Microbes : Habitat
• Microbes live in almost every nook and cranny
you can think of, from 20 miles beneath the
Earth's surface to 20 miles overhead.
• They make a cyst around themselves when
the conditions are unfavorable. This way they
can even survive in outer space.
