BIOL 222 Lecture Notes - Lecture 8: Pilus, Lysis, Plasmid
Document Summary
Biol 222 lecture 8 bacteria and viruses. Bacteria divide by binary fission: results in genetically identical cells. Do not have mitosis, meiosis, or a nucleus. E. coli : most fundamental discoveries were made using e. coli. Ex gene regulation, genetic code, dna replication, transcription, translation, metabolism, protein secretion, membrane biology. Plasmids small circular molecules of dna: replicate like a mini chromosome. Fertility (f) factor - a specialized e. coli plasmid that can transfer from one cell to another: f + - cells with an f factor, f - - cells without an f factor. Hfr strain can transfer chromosomal genes to an f- recipient. Dna fragment can recombine with the chromosome and generate recombinants (requires a double cross over) A single x-over between the linear dna fragment from the donor and the circular chromosome of the recipient results in a nonviable linear chromosome.
