Page 126 - The Microworld Miracle

of the word, yet it does however display an unbelievable variety. A
virus possesses a genome of a rather large number of "letters."
Another more interesting feature is that the genome of every virus
in a matchless one-off.
Viruses possess various sequences of letters depending on
their length. The hepatitis B virus, for example, consists of 3,200 nu-
cleotides, or letters. The HIV virus has 10,000 nucleotides. Larger

viruses such as the herpes viruses that cause cold sores, have
around 100,000 nucleotides. Thanks to the information concealed in
their DNA, the only organs these organ-
isms possess, they can reproduce
and survive by entering other
cells. All these properties
have been squeezed into

their DNA.
Thanks to their supe-
rior abilities, viruses can al-
so change their genetic qual-
ities in a very short time. The
very same disease can exhibit dif-
Hepatitis
B virus ferent symptoms and varying de-
grees of virulence, thanks to virus-
THE MICROWORLD MIRACLE ges. The virus can enter a cell in its
es' ability to change their genetic
makeup. No vaccinations can be
effective against such diseases
because of these sudden chan-

virus

124 Herpes