DNA is a nucleic acid that contains the genetic instructions for the
development and function of living organisms. All living things
contain DNA, although DNA viruses are usually considered non-living.
The main role of DNA in the cell is the long term storage of
information. It is often compared to a blueprint, since it contains
the instructions to construct other components of the cell, such as
proteins and RNA molecules. The DNA segments that carry genetic
information are called genes, but other DNA sequences have structural
purposes, or are involved in regulating the expression of genetic
information. In eukaryotes such as animals and plants, DNA is stored
inside the cell nucleus, while in prokaryotes such as bacteria, the
DNA is in the cell's cytoplasm. The major function of DNA is to encode
the sequence of amino acid residues in proteins, using the genetic
code. To read the genetic code, cells make a copy of a stretch of DNA
in the nucleic acid RNA. These RNA copies can then be used to direct
protein biosynthesis, but they can also be used directly as parts of
ribosomes or spliceosomes.
Read the rest of this article:
http://en.wikipedia.org/wiki/DNA
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Today's selected anniversaries:
1689:
Glorious Revolution: Instead of James Francis Edward Stuart the Prince
of Wales acceding to the throne, his sister Mary and her husband
William were proclaimed co-rulers of England.
(
http://en.wikipedia.org/wiki/Mary_II_of_England)
(
http://en.wikipedia.org/wiki/William_III_of_England)
1880:
Thomas Edison observed the Edison Effect, which later formed the basis
of John Ambrose Fleming's vacuum tube diodes.
(
http://en.wikipedia.org/wiki/Thermionic_emission)
1945:
The RAF Bomber Command began the strategic bombing of Dresden in
Saxony, Germany, resulting in a lethal firestorm which killed tens of
thousands of civilians.
(
http://en.wikipedia.org/wiki/Bombing_of_Dresden_in_World_War_II)
1984:
Konstantin Chernenko succeeded the late Yuri Andropov as General
Secretary of the Communist Party of the Soviet Union.
(
http://en.wikipedia.org/wiki/Konstantin_Chernenko)
2004:
Researchers at Harvard University discovered BPM 37093, the universe's
largest known diamond, white dwarf star.
(
http://en.wikipedia.org/wiki/BPM_37093)
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Wikiquote of the day:
Every man's life (and ... every woman's life), awaits the hour of
blossoming that makes it immortal ... love is a divinity above all
accidents, and guards his own with extraordinary obstinacy. -- Eleanor
Farjeon
(
http://en.wikiquote.org/wiki/Eleanor_Farjeon)