MBG 2040 Chapter Notes - Chapter 8: Phenylalanine, Joshua Lederberg, Maclyn Mccarty

• School: University of Guelph
• Department: Molecular Biology and Genetics
• Course: MBG 2040
• Professor: James Uniacke

Document Summary

If we examine bacteria or viruses, we almost always find that they manifest different phenotypes and that these differences are heritable. Key points: their small size, short generation time, and simple structures have made bacteria and viruses valuable model systems for genetic studies, many basic concepts of genetics were first deducted from studies of bacteria and viruses. Bacteriophage lambda: contains about 50 genes in a double-stranded dna molecule 48,502 base pairs long, packaged in the lambda head. It enters a cell and is converted to a circular form. In its integrated state, the lambda chromosome is called a prophage, and its lytic genes are kept turned off. Is the process sensitive to dnase, an enzyme that degrades dna: all three parasexual processes do not occur in all bacterial species; in fact, transduction probably is the only process that occur in all bacteria. Key points: three parasexual processes transformation, conjugation, and transduction occur in bacteria.