Part 1: Germinal vs. Somatic mutations

Examples of somatic mutation

A. a gray stripe of hair on a dark-headed person is likely a somatic cell mutation specific to the skin cells on only that part of the head (occurred later in development) 2. a mutation in a precursor cell for a specific organ or tissue type 3. Cancer cell development (can be germinal)

Germ-line mutation/germinal mutation

a mutation that exists or has occurred in the sperm or egg and is passed to the progeny

somatic mutation

a mutation that is not present in the germ-line of the organism. This mutation will change the phenotype of the individual containing it, but it will not be passed to the progeny

The Germ-line mutation would be present in

almost all of the resulting organism's cells- if these cells include the future germ-line cells, then this mutation will be inherited by the offspring and considered a germ-line mutation.

Germ-line mutations can also occur

during early embryonic development when the embryo is made up of only a few cells

examples of germ-line mutations

inherited genetic disorders such as cystic fibrosis, Huntington, etc. Albinism

In general, if a somatic mutation occurs early during organismal development, it will However, if the mutation occurs later during organismal development, the mutation may

likely be in many cells and may seem like the mutation exists in the entire organism. only be in a few cells within the organism.