Advances in Genetics For thousands of years people have tried to develop plants and animals with desirable traits

Developing Desirable Traits Selective Breeding Cloning Genetic Engineering

Selective Breeding Selecting a few organisms with desired traits to serve as parents for the next generation Usually focus on the value of the plant or animal: cows that produce more milk or disease resistant plants One technique is inbreeding, which is crossing individuals with identical or similar genes with the intent of producing offspring with desired traits –Thoroughbred horses are bred for speed –Inbreeding increases the probability of inheriting disorders as well Hybridization: crossing two different individuals hoping to inherit the best traits from both parents

Cloning A clone is an organism that is genetically identical to the organism from which it was produced Plants can be cloned by using cuttings Dolly the sheep was the first clone of an adult mammal. The nucleus of a sheep’s egg cell was replaced by the nucleus of a cell from a six year old sheep Clones of pigs and calves have now also been created

Genetic Engineering Genes from one organism are transferred into the DNA of another Often called “gene splicing” Early successes involved Bacteria Today many proteins are produced in genetically engineered bacteria Many crops have been engineered to be more resistant Genes have been inserted into animals to develop medicines for humans

Gene Therapy A type of genetic engineering where working copies of a gene are inserted into the cells of someone with a genetic disorder Still in experimental stages For Cystic Fibrosis patients working genes for production of a protein for proper lung function are inserted into harmless viruses and introduced to the body

DNA Fingerprinting DNA Fingerprinting is now being used to solve crimes DNA samples are obtained (hair, skin and blood are common) and used to identify people. Only identical twins can have the same DNA DNA is cut into fragments and patterns are compared to DNA from suspects

Human Genome Project A genome is all the DNA in one cell in an organism The objective of the Human Genome Project is to identify the DNA sequence of every gene in the human genome This will give us the amino acid sequence for every protein This would help us understand how the body works and develops and what causes things to go wrong. This might provide strategies for treatment and prevention of disorders.