Page 18 - The Secrets of the DNA

on top of each other to form the genes. Each
gene, which comprises one portion of DNA
molecule, determines a particular feature of
the human body. Countless properties like height,
eye colour, the material and the shape of the nose,
ear, and skull are formed by the command of the
related genes. We can compare every one of these
genes to the pages of a book. On the pages there are
scripts made up of the letters A – T – G – C.
There are approximately 200,000 genes in the
DNAof a human cell. Every gene is composed of a
special sequence of nucleotides, the number of
which ranges between 1000 and 186,000 according
to the type of the protein it correlates. These genes hold
the codes of nearly 200,000 proteins that function in the
human body and control the production of these pro-
teins.
The information stored in these 200,000 genes con-
stitute only 3 % of the total information in DNA. The
remaining 97 % still maintains its mystery today. The
recent studies showed that this 97 % unknown part
includes vital information about the survival of the cell
and the mechanisms that control the highly complex activ-
ities within the body. Yet there is still a great distance to go.
The genes are located in the chromosomes. There are 46
chromosomes in the nucleus of every human cell (except
for the reproduction cells). If we compare every one of the
chromosomes to a book volume made up of gene pages, we
may say that in the cell lies a 46-volume "cell encyclopedia"
which covers all the characteristics of a human being.
Remembering the previous encyclopedia example, this cell
encyclopedia is equivalent to the knowledge contained in a

THE SECRETS OF DNA
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