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Announcements. Ch. 8 Part 2 Homework due today Ch. 8 Part 3 Homework due Friday Online quiz due at midnight TONIGHT Lab tomorrow at 8 AM Review Session: Tuesday March 4 th at 9 AM and 10 AM…Bring muddiest points. Bacterial Genetics Chapter 8 Part 3. Recap (2 Minutes).
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Announcements • Ch. 8 Part 2 Homework due today • Ch. 8 Part 3 Homework due Friday • Online quiz due at midnight TONIGHT • Lab tomorrow at 8 AM • Review Session: Tuesday March 4th at 9 AM and 10 AM…Bring muddiest points
Recap (2 Minutes) What are the mechanisms by which bacteria can acquire new genes? Answer: DNA-mediated transformation Transduction Conjugation
Revisiting Plasmids • Common to bacteria • Double stranded DNA • They have ori • Do not code information critical to a cell’s life • Do provide an advantage for certain environments • Vary in amount of genes they carry: few to many • Narrow host range • Transferred by conjugation • Resistance plasmid-encode resistance to many antibiotics
Horizontal Gene Transfer: Chromosome Transfer • Less common than plasmid transfer • Involves Hfr cells: High frequency recombination • The plasmid integrates into the chromosome • So, part of the chromosome ends up getting transferred to the F- cell
Horizontal Gene Transfer: Chromosome Transfer-Formation of Hfr Cell
Revisiting Transposons • They can disrupt genes • They can also transfer genes from one bacteria to another • 2 types: insertion sequence and composite sequence