somatic mutations
Once again, a mutation is the change in the DNA or RNA sequence. In multicellular organisms, mutations can be subdivided into germline mutations and somatic mutations. Germline mutations occur in the DNA of sex cells, or gametes, and are therefore potentially very serious. These mutations can be passed to the next generation. If the zygote contains the mutation, every cell in the resulting organism will have that mutation. If the mutation results in a disease phenotype, the mutation causes what is called a hereditary disease. Somatic mutations , which occur in somatic, or body, cells, cannot be passed to the next generation offspring . Mutations present in a somatic cell of an organism will be present by DNA replication and mitosis in all descendants of that cell. If the mutation is present in a gene that is not used in that cell type, the mutation may have no effect. On the other hand, the mutation may lead to a serious medical condition such as cancer.