Replication
of
DNA
Replication
of
DNA -
One
of
the
most
important
properties
of
DNA
is
that
it
can
make
exact
copies
of
itself.
This
process
is
called
replication,
and
is
the
very
basis
of
life.
The
two
strands
of
a
DNA
double
helix
are
united
by
hydrogen
bonds
between
the
purine
and
pyrimidine
base
pairs.
When
the
hydrogen
bonds
break
the
two
strands
separate
and
unwind.
The
nucleus
contains
free
nucleotides
which
form
the
nucleotide
pool.
The
nucleotides
include
those
containing
adenine,
guanine,
cytosine
and
thymine
nitrogenous
bases.
These
free
nucleotides
pair
with
the
nucleotides
of
the
two
separated
strands
by
means
of
hydrogen
bonds.
Free
adenine
nucleotide
pairs
with
the
thymine
nucleotide
of
the
strand,
and
free
guanine
nucleotide
with
the
cytosine
nucleotide
of
the
strand,
etc.
(A-T
and
G-C
pairing).
In
this
way
a
new
strand
is
formed
around
each
old
strand.
The
result
of
replication
is
the
formation
of
two
double
helices,
each
identical
to
the
original
double
helix.
DNA
is
found
mostly
in
the
chromosomes.
When
the
chromosome
divides
into
two
during
mitosis
the
two
daughter
chromosomes
have
identical
DNA
double
helices.
Now,
all
the
cell,
in
the
body
are
ultimately
derived
from
the
zygote
by
repeated
division.
It
thus
follows
that
they
all
have
exactly
similar
DNA.
Replication
ensures
that
the
genes,
which
are
segments
of
the
DNA
molecule,
are
present
in
identical
sets
in
all
cells
of
the
body
of
an
individual.
DNA
fulfils
the
requirement
of
a
genetical
materials
the
ability
to
replicate.
|