Chapter 12

Genetic Engineering

  Chimera fragments of DNA from two organisms that have been joined to make a single DNA molecule

I. Modifying the Living World

A.     Strategies for breeding  organisms

1.      Selective Breeding- choosing the parents based upon their traits for the next generation of offspring.

2.      Inbreeding- maintaining the desired traits by crossing individuals closely related.

a.      Purebred pets are maintained this way.

3.      Hybridization- crossing individuals of different species but closely related.

a.      For plants, hardier crops species generally produced

4.      Mutagens- substances that cause mutations in organisms

a.      Ex: seedless watermelons, hairless mice

II. Genetic Engineering

A.     Techniques

1.      DNA sequencing reading one strand of DNA

a.      the process of electrophoresis is used to identify the bases and the order in which they are attached to the strand.

2.      Transgenics-  Organisms that have foreign DNA inserted into their cells.

a.      Bacteria are used to make human growth hormones and insulin.

b.      Plants can express new phenotypes or produce their own nitrogen compounds.

c.       Carp made bigger and faster from trout hormone.

3.      Cloning- Creation of an organism that is genetically identical to the parent

a.      Dolly was not the first..

b.      Electrical shock and hormones are used to jump-start the egg to start dividing.

c.       A surrogate mother is needed to grow the egg

III. New Human Genetics

A.     Human Genome project The entire DNA code for one human being has been decoded

B.     DNA fingerprinting- tool used in criminal investigations identify those who may have committed a crime by matching DNA from the scene to the individual.

a.      Electrophoresis is used to identify the pattern of repeated DNA fragments.

b.      Every person has a unique pattern of repeats

C. Gene Therapy- inserting new gene to treat diseases