The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
A point mutation is a change in a single base in the coding part of the deoxyribonucleic acid (DNA). Point mutations are changes in one base pair of the DNA and they can vary in their effects. They can range from being unobservable to being fatal to the organism.
Due to the inbuilt redundancy of the code of DNA (whereby several different triplet codons can code for the same amino acid) some point mutations are neutral, that is they have no observable effect, the same amino acid is still produced in the same location. Other point mutations can substitute the amino acid produced in the polypeptide chain. This can produce a non-functioning protein, which can then affect the whole organism even leading to death. In some cases the protein produced under the action of the point mutation can actually perform better than the original form. Where this beneficial effect occurs it may lead to a greater ability to survive in the given environment, thus leading to a greater number of offspring potentially being produced with the concomitant chance of a wider spread over the whole population for this new form of the gene. Some point mutations change the section of DNA affected from sense to nonsense. When nonsense DNA is found it is a signal for the cell to stop making the polypeptide chain. This is the production of a stop codon.