BIOL 105 Lecture Notes - Lecture 7: Noncoding Dna, Alternative Splicing, Intron
Document Summary
Outline: review of genetics, types of mutations, rates of mutations, mutational effects, mutations are random, not directed, test your knowledge! Review of genetics: what is the source of genetically based individual variation that allows natural selection and the evolutionary response to selection to occur, theory of particulate inheritance by gregor mendel. Eukaryotes: only a small portion of dna encodes phenotypes (mutations in the rest of the genome do not matter to phenotypic evolution), much of the structure of eukaryotic genomes is not made of genes. Instead, much of the gene material is noncoding dna: most of the noncoding dna was originally called junk , but now we realize that non- coding dna can have critical regulatory functions. Noncoding dna has highly repetitive stop codons. Transposable elements and other selfish dnas are a major source of noncoding. Dna: alternative splicing can produce multiple mrna variants, only a portion of each gene is actually transcribed.
