AP bio: Bacterial Transformation and Transduction

The different strains of foreign DNA expressed in E. coli in Cohen and Boyer's experiment. 

Putting the bacteria into heat shock to induce them to take in foreign DNA.

One of the foreign DNA from the plasmid that is expressed in the transformed E. coli bacteria that grew on the bacteria culture plate.

Transformation: In this process, bacteria take in DNA molecules.  When they reproduce, the DNA molecule will also replicate with their own DNA.  The bacteria can be induced to take in certain DNA molecules, such as in Stanley Cohen and Herbert Boyer's experiment.  Cohen and Boyer inserted recombinant DNA into E. coli bacteria via a plasmid.  They created a heat shock by lowering and raising the temperature to make the bacteria take in the plasmid, then put the transformed bacteria into a culture plate.  The result is that the transformed bacteria would express the foreign DNA.

The process of bacterial transduction.

Transduction: In this process, bacteria transfer foreign DNA to each other via a virus.  When bactiophages infect a bacterium, the viral DNA can be included in the bacterial genome.  This way, when the bacteria reproduces that viral DNA is also reproduced along with the bacteria's own original DNA.


Sources:
The pictures and information for transformation are taken from this site: http://www.dnalc.org/view/15916-DNA-transformation.html.
The information for the transduction is from Campbell and Reece's Biology, Sixth Edition.  The picture for transduction is from: http://bacteriakingdoms.com/transduction-bacteria/.