Gene
Mutation
Gene
Mutation -
In
most
organisms
genes
are
segments
of
DNA
molecules.
In
the
broad
sense
the
term
'mutation'
refers
to
all
the
heritable
changes
in
the
genome,
excluding
those
resulting
from
incorporation
of
genetic
material
from
other
organisms.
A
mutation
is
an
abrupt
qualitative
or
quantitative
change
in
the
genetic
material
of
an
organism.
Mutations
may
be
intragenic
or
intergenic.
Intragenic
mutations
or
point
mutations
include
alterations
in
the
structure
of
the
DNA
molecule
within
a
gene.
In
a
point
mutation
there
is
a
change
in
the
normal
base
sequence
of
the
DNA
molecule.
This
change
results
in
a
modification
of
the
structural
characteristics
or
enzymatic
capacities
of
the
individual.
The
unit
of
gene
mutation
is
the
muton.
This
may
consist
of
one
or
many
nucleotide
pairs
Intergenic
mutations,
of
which
chromosomal
changes
in
structure
are
examples,
involve
long
regions
of
DNA,
i.e.
many
genes
These
include
deletion
or
addition
of
segments
of
chromosomes,
resulting
in
deficiency
and
duplication,
respectively.
In
large
deletions
a
base
sequence
corresponding
to
an
entire
polypeptide
chain
is
sometimes
lost.
Such
mutations
are
very
useful
in
genetic
mapping.
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