Question

What is an example of a somatic mutation?

Answer 1

Hint: There are two primary cell types in eukaryotic organisms. Germ cells and somatic cells. Either cell can become mutated. If a gene of a germ cell is mutated, the mutation is termed as a germinal mutation. Germinal mutation can be inherited from one generation to the next. All non-germline tissues arise from somatic cells. Mutation in somatic cells is termed as somatic mutation. Because they do not occur in germinal cells, the mutation can not be passed from one generation to the next by sexual means.

Complete answer:
Somatic mutations are important in the diversity of the T cell receptors, B cell receptors, and antibodies. They are frequently caused by environmental factors and despite proficient DNA repair mechanisms they can accumulate in the DNA of any Organism. In healthy tissues, somatic mutations are present at a frequency of about 2-6 mutations per million bases, and about three somatic mutations per healthy human individual.
A unique class of somatic mutations are cancer tumors. Cancer is a disease characterized by breaking down of regulatory mechanisms of normal cells, uncontrolled division of cells, and the movement of proliferating cells to other parts of the body. Division and differentiation of new cells are highly regulated. Whenever there is breakdown of this regulatory mechanism, a cell develops the ability to undergo uncontrolled repeated division forming a clone of cells. There is no adherence. The cells slip past one another forming a mass of undifferentiated cells called tumor or neoplasm. Cells pass out from the tumor to new sites for forming secondary tumors. This spread of cancerous cells from one part to the other parts is called metastasis.
Causes of cancer: Carcinogens are agents which cause cancer. Carcinogens can be physical, chemical, and biological agents. Carcinogens are of three types: Oncogenic transformation: They change genetic material from non- oncogenic state to oncogenic state, e.g., radiation, chemicals. Tumor promoters: Promote tumor formation through proliferation of cells that have already undergone oncogenic transformation, e.g., growth factors, hormones. Tumor Viruses: They cause cancer through oncogenic transformation. E.g., DNA and RNA Viruses.

Note:
Somatic mutations can be any genomic variation; deletion, insertion, repeats, multiplication, loss of copy number. Chromosomal somatic mutations occur when somatic cells divide. Structural aberrations result from chromosome breakage and incorrect repairing or the unequal exchange of material during chromosome separation. Structural aberrations include duplication; when a portion of chromosome appears twice, deletion; when a part of chromosome is missing, inversion; when part of chromosome is in inverse orientation, translocation; when genetic material has been interchanged between non-homologous chromosome.