Somatic mutation
This happens in a single
cell of a developing somatic tissue. This cell is the progenitor of a
population of identical mutant cells, all of which have descended from the cell
that mutated. Additionally, they do not occur in cells that give rise to gametes;
therefore, the mutation cannot be passed on to descendants by sexual means. Somatic
mutation are often called acquired mutation because the change in genetic structure
is not inherited from a parent for they do not affect the germline. Thus, to
maintain the mutation, the individual containing the mutation must be clone.
Example: In red delicious apple, the
mutant allele that determine the golden color of an apple arose in a flower’s
ovary wall, which eventually developed into a fleshy part of the apple. The seeds
are not mutant so it will still give rise to red apple tree. Therefore, the golden
delicious apple originally arose from a mutant branch of a red delicious apple
tree.
Germline mutation
If a gene is altered in a germ cell,
the mutation is called germinal mutation. Germline tissue is set aside in the
course of development to form sex cells. Germ cells gives rise to gametes, so if
a mutant sex cell participates in the fertilization, then the mutation will be
passed on to the next generation. Moreover, germinal mutations will not be
expressed in the individual containing the mutation.
<span>Example: A hereditary case of
albinism are often link to germline mutation where individual of this disorder
are more prone to many types of cancers and may have impaired visions.</span>
