What is DNA? DNA stands for deoxyribonucleic Acid.
It is hereditary material in human beings and almost all other organisms.
Nearly every cell in human body has the same DNA. Most DNA is located in the
cell nucleus. The information in DNA is stored as a code made up of four
bases: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T). Human DNA consists of about 3 Billion bases, and
more than 99% of those bases are the same in all human beings. The order or
sequence of these bases determines the information available for building and
maintaining an organism, similar to the letters of the alphabets appear in
certain order to form words and sentences.
DNA bases pair up
with each other, A with T and C with G to form units called base pairs. Each
pair is attached to a sugar molecule and phosphate molecule. Together, a base,
sugar and phosphate are called nucleotide. Nucleotides are arranged in two long
strands that form a spiral called a double helix. The structure of the double
helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs
and the sugar and phosphate molecules forming the vertical sidepieces of the
ladder.
An important property
of the DNA is that it can replicate, or make copies of itself. Each strand
of the DNA in the double helix can serve as a pattern for duplicating the
sequence of the bases. This is critical when cells divide because each new cell
needs to have an exact copy of the DNA present in the old cell.
Carl Sagon says in
his book: “Cosmos” “And at the very heart of life on earth, the proteins that
control cell chemistry, and the nucleic acid (DNA) that carry hereditary instructions,
we find these molecules to be identical in all the plants and animals. An oak
tree and I (Carl Sagon) are made of the same stuff. If you go back far enough,
we have common ancestor.”
This is an extract
taken from the best selling science book “Cosmos” a scientist and atheist: Carl
Sagon, director of Viking Mission to Mars, at NASA.
The important to note
is that all living things are the same with respect to their fundamental
ingredients. All living things have chromosomes for storing genetic information.
The chromosomes are made of DNA like a shirt is made of threads.
If we go back
fourteen centuries back, the Gateway of Knowledge of the city (Noble Prophet
s.a.w.s.), Imam Ali (a.s.) says in Nahjul Balaghah, Sermon 183 page 305 line
13: “If you tread in the paths of your imagination and reach extremity it won’t
lead you anywhere except that the Creator of the ant is the same who is the Creator
of the date palm because everything has (the same) delicacy and detail and
every living being has little difference.”
It appears that Imam Ali (a.s.) and Carl Sagon are
contemporaries, but everyone knows that there is a time difference of fourteen centuries
between them.
DNA was discovered in 1950 and it was established that all
living things from bacteria to virus plants to human beings are made of DNA and
that there is little difference between them.
Can we name Imam Ali
(a.s.) as the First Molecular Biologist!
Sources used:
Nahjul Balagha A
Literary Master Piece of Sermons, letters and sayings of Imam Ali (a.s.)
Cosmos By
Carl Sagon
What is DNA? Your guide
to genetics Home Reference
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