Chapter 13.3 Cell Transformation

Why would we modify DNA if we couldn’t put it back into an organism? During transformation, a cell can take DNA from outside the cell. This DNA becomes part of the cell’s DNA.

Transforming Bacteria Bacteria can be transformed with recombinant DNA (DNA with parts from other organisms). Bacteria have plasmids – these are small circular pieces of DNA. Plasmids have a DNA sequence that helps promote replication – this makes sure that any foreign DNA in a plasmid will replicate. Plasmids also have a genetic marker – a gene that makes it possible to separate bacteria that have the plasmid vs. those that do not.

Transforming Plant Cells Plants can be transformed using bacterial plasmids. They have a bacteria that produces a plasmid that makes tumors in plants. Scientists can inactivate the tumor gene and be able to insert foreign DNA into this plasmid. Sometimes, when cell walls are removed, plant cells can directly take up DNA. The only way transformation is successful is if the recombinant DNA is incorporated into the chromosomes of the plant.

Transforming Animal Cells Animal cells can in some ways be transformed the same as plant cells. For a gene to be inserted it usually needs to be inserted in an egg cell. .