15.1 Selective Breeding and 15.2 Recombinant DNA Lesson Overview 15.1 Selective Breeding and 15.2 Recombinant DNA

Selective Breeding Humans use selective breeding to produce animals and plants with certain desired traits. Only those organisms with wanted characteristics produce the next generation. Ex. - Different breeds of dogs Different types of plants (corn, bananas)

Recombinant DNA Recombinant DNA = DNA from two or more sources. A gene from one organism can be attached to the DNA of another organism. restriction enzymes = “DNA scissors”, they cut DNA at specific spots.

Combining DNA Fragments Restriction enzymes cut DNA at specific sequences, making “sticky ends,” which are overhangs of DNA.

Combining DNA Fragments If two DNA molecules are cut with the same restriction enzyme, their sticky ends will bond together. The resulting molecules are called recombinant DNA.

Plasmids and Genetic Markers In addition to their own large chromosomes, some bacteria have small circular DNA molecules known as plasmids.

Plasmid DNA Transformation Using Human Growth Hormone

Cloning A clone is a member of a population of genetically identical cells produced from a single cell In 1997, Scottish scientist Ian Wilmut announced that he had produced a sheep, called Dolly, by cloning.

Cloning Animal cloning uses a procedure called nuclear transplantation. 1) take an unfertilized egg cell. 2) remove the nucleus. 3) add a nucleus from an adult cell. 4) the new cell develops into an embryo 5) implant the embryo in a “foster mom” where it develops until birth. Cloned cows, pigs, mice, and even cats have since been produced using similar techniques.

Cloning Animals—Nuclear Transplantation