Cheek Cells! - esci390

twoeggfinnishΒιοτεχνολογία

14 Δεκ 2012 (πριν από 4 χρόνια και 11 μήνες)

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What is a cell?


At a microscopic level, we are all composed of cells. Look at
yourself in a mirror
--

what you see is about 10 trillion cells
divided into about 200 different types. Our muscles are
made of muscle cells, our livers of liver cells, and there are
even very specialized types of cells that make the enamel
for our teeth or the clear lenses in our eyes!


If you want to understand how your body works, you need
to understand cells. Everything from
reproduction

to
infections to repairing a broken bone happens down at the
cellular level. If you want to understand new frontiers like
biotechnology and genetic engineering, you need to
understand cells as well.


What is the Cell theory?


the theory that all organisms are composed by one or
more cells, all cells are made up of pre
-
existing cells
and that cells are the basic building blocks of life in all
things. (proposed in 1838 by Matthias
Schleiden

and
by Theodor Schwann)


http://www.youtube.com/watch?v=dscY_2QQbKU&fe
ature=related