BIOL 123 Lecture Notes - Lecture 2: Rna Splicing, Microrna, Mobile Genetic Elements
Document Summary
Adaptations: traits that have evolved by natural selection. Mutations: any change to the genomic sequence of an organism. Gene expression can be regulated in a number of ways. Regulation of gene expression in eukaryotes is extremely flexible. One group of rnas that act as posttranscriptional regulators of gene expression. They bind to complementary sequences on specific mrnas and can enhance or silence the translation of genes. The human genome encodes more than 1000 of these tiny rnas. They bind to mrna molecules that would otherwise be translated into protein and act like switches, turning genes on and off in response to changes to the environment. Rna splicing can create multiple proteins from a single gene. It is the process of modifying rna after transcription but before translation, during which introns are removed and exons are joined together into a contiguous strand. The resulting strand of mrna contains only information from a gene"s exons.
