Bacteria are unicellular microorganisms. They are typically a few
micrometres long and have many different shapes including spheres,
rods and spirals. The study of bacteria is bacteriology, a branch of
microbiology. Bacteria are ubiquitous, living in every possible
habitat on the planet including soil, underwater, deep in the earth's
crust and even such environments as acidic hot springs and radioactive
waste. In all, there are around five nonillion (5 × 10<sup>30</sup>)
bacteria in the world. There are 10 times more bacterial cells than
human cells in the human body, with large numbers of bacteria on the
skin and in the digestive tract. Although the vast majority of these
bacteria are harmless or beneficial, a few pathogenic bacteria cause
infectious diseases, including cholera, syphilis, anthrax, leprosy and
bubonic plague. The most common bacterial disease is tuberculosis,
which kills about 2 million people a year, mostly in sub-Saharan
Africa. Bacteria are prokaryotes and, unlike animals and other
eukaryotes, bacterial cells do not contain a nucleus or other
membrane-bound organelles. Although the term bacteria has
traditionally been generally applied to all prokaryotes, the
scientific nomenclature changed after the discovery that prokaryotic
life consists of two very different groups of organisms that evolved
independently from an ancient common ancestor.
Read the rest of this article:
http://en.wikipedia.org/wiki/Bacteria
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Today's selected anniversaries:
1265:
Summoned by Simon de Montfort, the first English parliament held its
first meeting in the Palace of Westminster.
(
http://en.wikipedia.org/wiki/Palace_of_Westminster)
1320:
After reuniting Poland, Władysław the Short was crowned king in
Kraków.
(
http://en.wikipedia.org/wiki/Piast_Poland)
1885:
LaMarcus Adna Thompson patented the roller coaster.
(
http://en.wikipedia.org/wiki/roller_coaster)
1892:
The first official basketball game was played at the YMCA in
Springfield, Massachusetts.
(
http://en.wikipedia.org/wiki/basketball)
1942:
Nazis at the Wannsee conference in Berlin decided the "final solution
to the Jewish question", leading eventually to the Holocaust.
(
http://en.wikipedia.org/wiki/Wannsee_conference)
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Wikiquote of the day:
What is an artist? A provincial who finds himself somewhere between a
physical reality and a metaphysical one.... It’s this in-between that
I’m calling a province, this frontier country between the tangible
world and the intangible one — which is really the realm of the
artist. -- Federico Fellini
(
http://en.wikiquote.org/wiki/Federico_Fellini)