MICROORGANISMS ARE CELLS & ORGANISMS
1. rRNA based Phylogeny: The Universal Tree of life/B>
2. Microbiology is the study of microbes. Microbes are:
- Phylogeny places all cells in 3 domains (the highest level order or
superkingdoms): Bacteria, Archaea and Eucarya
- Members of domain Bacteria and Archaea are procaryotic in nature and fungi,
algae, protozoa, animal and plant cells (domain Eucarya) are Eucaryotic
- Members of domain Bacteria, Archaea and some members of domain Eucarya
(fungi, algae, protozoa) are called microorganisms
3. Microorganisms have hall marks of a cell ie they are single celled
a large & diverse group of organisms
exist as single cells or cell clusters
microscopic or macroscopic (mushrooms, algae)
Self feeding or nutrition
Self replicating or growth
4. Microorganisms are given names
Binomial system of nomenclature used by Linnaeus for plants & animals.
Genus & species are underlined.
5. Microorganisms are ubiquitous in nature
ubiquitous in nature (air water, GI tract, high temps (thermophiles), low
temperatures (psychrophiles), saline (halophiles), acidic pH (acidophiles),
alkaline pH (alkalophiles).
6. Viruses are the living dead?
Author and HTML'd by: Dr Bharat Patel <B.Patel@griffith.edu.au>
[Created 18 Sept 1995]
Extremely small measured in nanometers and observed with an electron microscope.
Unable to live & multiply independently, has genetic material (either
DNA or RNA) but no translationary machinary for protein synthesis.
Acquires features of a living system only when it associates itself with
a living host
Hosts include fungi, protozoa, bacteria, algae.
Infection may not always lead to a disease, delayed disease symptoms (eg
[Modified 24 July 1997]