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Lecture AP Biology - Chapter 27: Bacteria

After studying this chapter you will be able to: Distinguish between the cell walls of gram-positive and gram-negative bacteria; state the function of the following features: capsule, fimbriae, sex pilus, nucleoid, plasmid, and endospore; explain how R plasmids confer antibiotic resistance on bacteria; explain the importance of/uses for prokaryotes | Ch. 27 Warm-Up What was Frederick Griffith’s contribution to our understanding of DNA? (Refer back to Ch. 16) How do bacteria replicate? Lab 6A Warm-Up What are plasmids? What gene(s) are on the plasmid being used in this lab? How can we know if cells have been successfully transformed in this lab? Bacteria Chapter 27.2 What you need to know: Mechanisms that contribute to genetic diversity in prokaryotes, including transformation, conjugation, transduction, and mutation. Genetic Diversity in Prokaryotes Factors: Rapid reproduction (binary fission) Mutations – errors in replication Genetic recombination Genetic Recombination in Bacteria Transformation: uptake of foreign DNA from surroundings Transduction: viruses transfer genes between prokaryotes Conjugation: DNA transferred from one to another Transformation Uptake of foreign DNA from surroundings Observed by Griffith (bacteria & mice) Plasmids Small ring of DNA that carries a few genes Replicates separately from bacterial chromosome Can carry genes for antibiotic resistance Used frequently in genetic engineering for gene cloning AP Bio Lab 6A - Transformation Using plasmids and bacteria in genetic engineering Gene Cloning Transduction Viruses (bacteriophages) carry bacterial genes from one host cell to another Recombine DNA of donor and recipient cell Conjugation One cell donates DNA to another Donors cell extends a sex pilus (“mating bridge”) through which DNA is transferred Requires the presence of a piece of DNA called the F factor to produce the . | Ch. 27 Warm-Up What was Frederick Griffith’s contribution to our understanding of DNA? (Refer back to Ch. 16) How do bacteria replicate? Lab 6A Warm-Up What are plasmids? What gene(s) are on the plasmid being used in this lab? How can we know if cells have been successfully transformed in this lab? Bacteria Chapter 27.2 What you need to know: Mechanisms that contribute to genetic diversity in prokaryotes, including transformation, conjugation, transduction, and mutation. Genetic Diversity in Prokaryotes Factors: Rapid reproduction (binary fission) Mutations – errors in replication Genetic recombination Genetic Recombination in Bacteria Transformation: uptake of foreign DNA from surroundings Transduction: viruses transfer genes between prokaryotes Conjugation: DNA transferred from one to another Transformation Uptake of foreign DNA from surroundings Observed by Griffith (bacteria & mice) Plasmids Small ring of DNA that carries a few genes Replicates separately from bacterial chromosome Can carry genes for antibiotic resistance Used frequently in genetic engineering for gene cloning AP Bio Lab 6A - Transformation Using plasmids and bacteria in genetic engineering Gene Cloning Transduction Viruses (bacteriophages) carry bacterial genes from one host cell to another Recombine DNA of donor and recipient cell Conjugation One cell donates DNA to another Donors cell extends a sex pilus (“mating bridge”) through which DNA is transferred Requires the presence of a piece of DNA called the F factor to produce the pilus