BIOL 1107 Chapter Notes - Chapter 16: Neurospora Crassa, Edward Tatum, George Beadle
Document Summary
Dna is transcribed to messenger rna by rna polymerase. Mrna is translated to proteins by ribosomes genetic info is converted from dna rna proteins each amino acid in a protein is specified by a group of 3 bases in messenger rna. Mutations are random changes in dna: ranging in extent from single bases to large chromosome regions, may or may not produce changes in phenotype. Early advances showed that genes carry the instructions for making & maintaining an individual. In order to infer what a particular gene does, george beadle & edward tatum proposed damaging a gene, creating a mutant, & then observing the resulting effect on the mutant"s phenotype. Nonfunctioning alleles are now called, knock-out, null, loss-of-function alleles. To test hypothesis, beadle & tatum damaged genes in the bread mold neurospora crassa, & observed that defects in particular genes resulted in the mold"s inability to produce specific proteins.