Selective Breeding Definition: breeding or crossing of organisms with favorable traits –Allows the favorable allele to remain in the population Cats Domestic Crops –(Corn, Wheat, Fruit) Cows

Inbreeding Definition: mating of closely related organisms –Ensures that offspring are homozygous for favored traits –Greater chance of harmful recessive traits to appear

Hybrid Definition: the offspring of parents that have different forms of a trait –Closely related species are crossed Most Frequent in Plants (eg. Crops) Lion + Tiger = LIGER!!!

How can a breeder determine which organism (genotype) should be used for breeding? By crossing an organism with a homozygous recessive organism we can determine the genotype of our dominant individual by examining their offspring!

Test Cross Definition: a cross of an individual of unknown genotype with an individual of a known genotype –The known genotype is usually homozygous recessive In German Shepherds… DD or Dd = Normal Height Dog dd = Dwarf Dog

If known parent is homozygous recessive (dd) and the unknown is homozygous dominant (DD) DD d d All offspring are Dd and show dominant trait: Normal Height Dd

If known parent is homozygous recessive (dd) and the unknown is heterozygous (Dd) D d d d 50% of the offspring will be heterozygous and show dominant trait and 50% will show the recessive trait Dddd Dddd

Genetic Engineering Much faster and more valuable method for increasing allele frequency (favorable traits) in a population. Must cut or cleave the DNA and insert it into host organism. Also called Recombinant DNA Technology

Recombinant DNA Technology Made by connecting or recombining fragments of DNA from different sources Transgenic organism: organism that contains foreign DNA In order to do this you must isolate a fragment or small part of the DNA using restriction enzymes

Restriction Enzymes Definition: bacterial proteins that have the ability to cut both strands of the DNA molecule at specific nucleotide sequences There are hundreds of restrictions enzymes, each different in length and specification Gene Splicing – the rejoining of DNA fragments join “sticky ends” of fragmented DNA

Vector Definition: a means by which DNA from another species can be carried into the host cell Can be mechanical or biological

Types of Vectors Biological: –Viruses –Plasmid – small circular bacterial DNA Mechanical: –Micropipette – inserts DNA into host cell –Bullet – coated with DNA and shot into nucleus with “gene gun”

Stem Cells Stem cell: a cell that can continuously divide and differentiate into various tissues Adult humans have stem cells in bone marrow, these cells can be collected and used for medical treatments Stem cells from embryos have much more potential to develop into new tissues and have more potential uses

Stem Cells: Is it ethical? Leftover embryos from fertility clinics was main source for stem cells Now, stem cells can be cloned Which method is more acceptable?

Cloning Clone: organism or piece of genetic material that is genetically identical to one that was previously existing

Cloning: Is it ethical?

Applications of DNA Technology Animals: Used to investigate human diseases 1.Mice 2.Roundworms 3.Fruit fly Agriculture: 1.Strawberries – built-in frost protection 2.Resistance to herbicides, produce internal pesticides, and increase protein production

Applications of DNA Technology Industry: 1. Bacteria engineered to degrade oil 2. Bacteria engineered to extract minerals from ore Medicine: Bacteria engineered to… 1.Produce of growth hormone to treat dwarfism 2.Produce insulin for people w/ diabetes 3.Making of Aspartame – artificial sweetener

Gene Therapy: insertion of normal genes into human cells to correct genetic disorders DNA Fingerprinting: –Used by law enforcement to determine if suspect was at the crime scene –Uses PCR technique –Especially helpful because no two people are genetically identical

The Human Genome Project Organized in 1990, projected to be a 30 year project, rough completion in 2001 International effort Wanted to map and sequence the HUMAN GENOME – 80,000 genes on our 46 chromosomes

The Human Genome Project Made possible by the use of linkage maps Linkage maps: genetic map that shows the location of genes on a chromosome –Helps to also evaluate the rate of crossing-over

Why the Human Genome Project? Better understanding of the human body and condition Diagnosis of genetic disorders Identification of suspects in a criminal case