By Carolyn L. Driedger and William E. Scott, USGS -- Republished from USGS fact sheet 2008-3062. 1  Mount Rainier: The flat floor of the Puyallup River valley near Orting, Washington, is formed by deposits of the 500-year-old Electron lahar, which surged down from Mount Rainier (in background).
Substitution mutation. Definition. A type of point mutation in which a single nucleotide is substituted with (or exchanged for) a different nucleotide that may result in an altered sequence of amino acid during translation, which may render the newly synthesized protein ineffective.Supplement.n transversion, purine is substituted with pyrimidine or a pyrimidine with a purine. See also: point mutation. Please contribute to this project, if you have more information about this term feel free to edit this page. This page was last modified on 16 October 2008, at 00:53.This page has been accessed 109,894 times.
Nonsense mutations. With a nonsense mutation, the new nucleotide changes a codon that specified an amino acid to one of the STOP codons (TAA, TAG, or TGA). Therefore, translation of the messenger RNA transcribed from this mutant gene will stop prematurely.ingle base substitutions are also called point mutations. (If one purine [A or G] or pyrimidine [C or T] is replaced by the other, the substitution is called a transition. If a purine is replaced by a pyrimidine or vice-versa, the substitution is called a transversion .).