ICY SCIENCE: SCIENCE SPACE ASTRONOMY Spring 2014 | Page 65

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The sequence of these bases in a
DNA strand represent instructions
about an organism, for example a
particular sequence of three bases
may be an instruction for making a
specific kind of amino acid.
DNA replication happens with
remarkable accuracy. One human
cell takes only a few hours to copy
the entire 3 billion base sequence
in a human DNA. However, sometimes errors do occur; less than 1
error per billion bases. The wrong
base pair can get attached, or an
extra base pair may be added or
deleted.
It is these errors which form the
basis of evolution.

Source: http://evolution.berkeley.edu/evolibrary/article/evo_14

ICY SCIENCE | QTR 2 SPRING 2014