Genetic Technology Chapter 13

Selective Breeding Certain plants or animals are mated together over a period of several generations in order to produce offspring with desired traits. –domesticating animals and crops

Inbreeding Inbreeding is the mating of closely related individuals that results in purebred (homozygous) individuals Good for ensuring certain organisms have certain traits What is the problem with inbreeding? –Magnify undesirable traits like deafness in dalmation dogs

Hybrids The heterozygous individual Produced by crossing two purebred individuals HH x hh = Hh

Test Cross Used to figure out if an organism is purebred or a hybrid The crossing of an organism with an dominant phenotype and an unknown genotype to a homozygous recessive organism (tester).

Test Cross Example - on the board

Transgenic Organism Organism produced when DNA from one species is inserted into a completely different species. –Transgenic organism - contains foreign DNA

Genetic Engineering When a fragment of DNA from one organism is added to the DNA of another organism. –Called Recombinant DNA Technology –An example is the making of human insulin in bacteria

How We Use Genetic Engineering

1. Industry –Bacteria engineered to break down pollutants like oil –Making indigo dye

2. Medicine –Bacteria engineered to produce mass quantities of: human growth hormone, insulin, artificial sweeteners

3. Agriculture –Plants that are resistant to fungus, pesticides, and frost bite.

4. Forensic Science –Identify remains, victims, and perpetrators through DNA fingerprinting

Making Recombinant Bacteria through genetic engineering

1. The desired gene fragment is cut out of the genome using a restriction enzyme. –A restriction enzyme recognizes a specific sequence of DNA and always cuts DNA at that sequence. –Restriction enzymes often come from bacteria

Common restriction enzymes and where they cut

2.The cut DNA fragment is attached to a vector that will carry the fragment to a new organism’s cells. The vehicle is called a vector. –Biological vectors are plasmids (circular DNA found in bacteria) or viruses.

3.The vector with the DNA is transferred to a host cell usually a bacteria. A second enzyme helps the DNA fragment join with host DNA. The process is called gene splicing. 4.The host cell then divides and copies the recombinant DNA. A host cell (bacteria) will mass produce the protein coded for by the inserted DNA. –This is considered a form of cloning.

DNA Fingerprinting - CSI stuff Used to solve crimes, confirm paternity, identify remains, confirm identity. Process –Collect DNA samples (blood, semen, skin, hair root) –Magnify the DNA using polymerase chain reaction –Then cut the DNA with restriction enzymes & use Gel Electrophoresis to separate the fragments on a gel.

DNA Fingerprinting

The Human Genome Project - mapping the human genome There are approx 20, ,000 genes on 46 chromosomes. Around 3 billion nucleotide bases total. Completed in 2003 –Diagnosis genetic disorders –Gene therapy (correct genetic disorders)

DNA sequencing technology was used for the Human Genome Project It is a way to determine the sequence of nucleotide bases of DNA. 900 bases at a time With 3 billion bases, it took a long time!