Search results
Results from the WOW.Com Content Network
Silent mutations, also called synonymous or samesense mutations, are mutations in DNA that do not have an observable effect on the organism's phenotype. The phrase silent mutation is often used interchangeably with the phrase synonymous mutation ; however, synonymous mutations are not always silent, nor vice versa.
Point substitution mutations of a codon, classified by their impact on protein sequence. A synonymous substitution (often called a silent substitution though they are not always silent) is the evolutionary substitution of one base for another in an exon of a gene coding for a protein, such that the produced amino acid sequence is not modified.
A nonsynonymous substitution is a nucleotide mutation that alters the amino acid sequence of a protein.Nonsynonymous substitutions differ from synonymous substitutions, which do not alter amino acid sequences and are (sometimes) silent mutations.
Not all missense mutations lead to appreciable protein changes. An amino acid may be replaced by an amino acid of very similar chemical properties, in which case, the protein may still function normally; this is termed a neutral, "quiet", "silent" or conservative mutation.
Many mutations are silent mutations, causing no visible effects at all, either because they occur in non-coding or non-functional sequences, or they do not change the amino-acid sequence due to the redundancy of codons. [33] Some mutagens can cause aneuploidy and change the number of chromosomes in the cell. They are known as aneuploidogens. [34]
The genetic differences among divergent populations can involve silent mutations (that have no effect on the phenotype) or give rise to significant morphological and/or physiological changes. Genetic divergence will always accompany reproductive isolation, either due to novel adaptations via selection and/or due to genetic drift, and is the ...
The search engine that helps you find exactly what you're looking for. Find the most relevant information, video, images, and answers from all across the Web.
The neutrality index (NI) quantifies the direction and degree of departure from neutrality (where P n /P s and D n /D s ratios are equal). When assuming that silent mutations are neutral, a neutrality index greater than 1 (i.e. NI > 1) indicates negative selection is at work, resulting in an excess of amino acid polymorphism.