Ch. 27 Warm-Up1. What was Frederick Griffith’s

contribution to our understanding of DNA? (Refer back to Ch. 16)

2. How do bacteria replicate?

Lab 6A Warm-Up1. What are plasmids?

2. What gene(s) are on the plasmid being used in this lab?

3. How can we know if cells have been successfully transformed in this lab?

BacteriaChapter 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:1.Rapid reproduction (binary fission)2.Mutations – errors in replication3.Genetic recombination

Genetic Recombination in Bacteria

1. Transformation: uptake of foreign DNA from surroundings

2. Transduction: viruses transfer genes between prokaryotes

3. Conjugation: DNA transferred from one to another

TransformationUptake of foreign DNA from surroundingsObserved by Griffith (bacteria & mice)

PlasmidsSmall ring of DNA that carries a few genesReplicates separately from bacterial

chromosomeCan carry genes for antibiotic resistanceUsed frequently in genetic engineering for

gene cloninggene cloning

AP Bio Lab 6A - Transformation

Using plasmids and bacteria in Using plasmids and bacteria in genetic engineeringgenetic engineering

Gene CloningGene Cloning

TransductionViruses

(bacteriophages) carry bacterial genes from one host cell to another

Recombine DNA of donor and recipient cell

ConjugationOne cell donates DNA to anotherDonors cell extends a sex pilus (“mating

bridge”) through which DNA is transferredRequires the presence of a piece of DNA

called the F factor to produce the pilus