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4-1 Biotechnology Biotechnology Alter normal genetic make-up of organisms, including viruses, bacteria, plants, animals Breeding dogs – Biotechnology through the ages Early 2000 B.C.E – related to food production Selective breeding of plants – pollination by hand, covering flowers so that no pollen could fertilize the plant Use of micro-organisms in processes such as fermentation (yogurt and cheese – help of bacteria and fungi) Bread and beer – Today – reproductive technology – Potential for increasing world’s food supply, producing new types of food, uncovering treatment for various diseases DNA For much of history – did not know what makes heredity work or how traits were passed on to next generation Now – 1800’s – cell theory developed – basic unit of life 1850’s – Gregor Mendel discovered inherited characteristic in pea plants – genes 1953 – James Watson & Francis Crick – 1973 – Stanley Cohen and Herbert Boyer – 1984 – Alec Jeffreys – DNA fingerprinting – uses DNA to identify individual organisms 1993 – Michael Smith – altering genes on chromosomes 1997 – Ian Wilmut – lamb Dolly – first artifically cloned animal 4-2 Importance of DNA Cells rely on coded information to tell them what to do – Chromosomes are also found in nucleus – Nucleotide base A is always bonded to T and C is always bonded to G Proteins and DNA Each segment of 3 consecutive bases = One of most important messages carried out by DNA – proteins – most of the structure of cells and tissues in plants and animals Each protein – 20 different amino acids and can be combined in different ways to make different proteins Gene – Mutations DNA controls the characteristics of a cell – Sometimes mistakes occur – Mistake in sequence of coding for assembling amino acids into a protein – Can be inherited – useful, harmful, or have no effect on organism or cell in which it occurred Most common cause of mutations – Alter DNA code – Others – cause to lose control of cell division = rapidly and repeatedly producing cancer Chromosomal mutations – Chromosomal mutations in reproductive cells – Genetic Engineering Artifically combine genes in a cell Take DNA from the cell of one organism and move to another to produce a new combination = May be new protein for human insulin Began in 1970’s – bacteria Escherichia coli Placing plasmids (from bacteria during conjugation) in test tube together with fragments of DNA from another organism – enzyme is used to cut open plasmid – fragment then joins or splices into the plasmid = “Designer Genes”? Average – Genetic engineering – Also allows scientists to give organisms genes from other species which selective breeding cannot Crop plants – Livestock – Medicine – gene that is absent in a person may be supplied through genetic engineering Cloning Simple way to make a clone of a plant – cutting from a plant, place in water to grow roots then placed in pot and then it will produce a plant genetically identical to original 4-3 Biotechnology and Human Body 3000 known diseases linked to genes and scientists can diagnose more than 200 of them Genetic disease – Genetic screening – Picture of cell’s chromosome – Gene therapy – One method – Virus normally attacks cells by attaching to cell’s outer membrane and then pushing its own DNA into cell – Altered virus – splice a healthy gene into viral DNA and let virus transfer the gene into patient’s cells Avoid passing on disease to offspring, defective genes need to be located and altered in patient’s sex cells Mapping entire human genome – Human Genome Project – Work involved many nations, use DNA probes (short strands of labelled DNA) that attach to specific genes This helped find gene responsible for cystic fibrosis – Making Human Proteins Produce the product of the gene – diabetic individuals cannot produce own insulin 1978 – human gene for making insulin was transferred into bacteria – insulin manufactured by bacteria has the advantage of being human insulin which decreases the possibility of an allergic reaction (unlike insulin from cows or pigs) Bacteria also used to produce human growth hormone and interferon (protein for immune system) Animals and bacteria – Advantage of using mammals is that proteins can be collected in mammal’s milk – do not have to be killed 4-4 Biotechnology in Agriculture New crops – Cropbreeders can now select a specific genetic trait from one species and move it into the genetic code of a crop plant Gives breeders the alternative of using genes from unrelated species (including animals or micro-organisms) as well as plants Wheat variety – 1990’s – 86% of all genetically engineered crops in Canada were altered to be tolerant of herbicides – used to kill unwanted plants, weeds Herbicides can kill crops – given a gene to function in presence of herbicide = crops can be sprayed with concentration, spray less often (cost as well as environment) Canola – Ancestor is a plant called rapeseed – used in Asia and Europe in lamps, for cooking, in foods Today – Rapeseed grown in Canada since 1936 – high demand during WWII as one or most effective lubricants for metal engine parts Distinctive taste and disagreeable greenish color due to presence of chlorophyll, high concentration of erucic acid (suspected to cause cancer if ingested large amounts) Plant breeders – improve quality of rapeseed in 1968 – used selective breeding to develop low erucic acid 1974 – low erucic acid and low levels of glucosinolates Today 75% of Canola crops in Alberta, Manitoba and Saskatchwan are herbicide tolerant Most favourable overall combination of saturated and unsaturated fats for healthy diet Monoculture – New Animals Aquaculture – increasing important method of fish production due to decline of natural fish stocks in oceans and lakes Added genes for disease resistance to some varieties of fish and growth hormone genes have been introduced to fish eggs to increase size and growth rate of fish Antifreeze gene into Atlantic salmon – protein that prevents the fishes blood from freezing Hormones have been introduced to increase production of farm animal products Bovine Growth Hormone (BGH) – Concerns – using the hormone might increase chances of some types of infection in cows In 1999 – federal government did not approve use of BGH for milk production in Canada 4-5 Biotechnology in the Environment How to clean up toxic wastes left over – Canada – Across Canada – over 1000 sites are contaminated with hazardous materials 1980’s – look for ways to use micro-organisms to break down the complex compounds in toxic wastes = Decomposers (bacteria, fungi, micro-organisms) use dead plant and animals as food Different species of these – Trick is to find the right ones for the substances Micro-organisms have been found to break down toxic compounds such as methylene chloride Most often requires a group of organisms each responsible for a certain step – called consortia Injecting micro-organisms into ground along with nutrients that will help them grow Others – only oxygen or nutrients are needed to nourish micro-organisms that are already in soil Cost effective (only 1/5 the cost of previous methods) Treating contamination without causing major disturbance to area and minimal intervention 1989 – Alaska – 33 000 sea birds, 146 bald eagles, 980 sea otters had been found dead Oil covered 1600km of shoreline To remove oil – Between 1976 and 1987 – over 300 significant oil spills occurred off Canada’s east and west coasts 1988 – Washington state – Mercury, copper, zinc, lead – Released into environment by industrial and mining activities, urban storm runoff, leaching of rocks and soil by acid rain Bacteria, fungi, algae – Cabbage, mustards, radishes – These plants can be genetically altered to take up specific metals from the soil Plants must be harvested and then disposed safely to remove pollutants Species Preservation Overfishing, pollution, global climate change – Oceans – organisms have unique biochemical characteristics that provide opportunities for solving a variety of medical problems Bacterium that lives with sponges and sea squirts – Many sponges and corals – make chemicals that reduce inflammation and pain of acute asthma, arthritis and injuries Other marine organisms – Bred in captivity to increase numbers Inbreeding – Solution – DNA fingerprinting – identify individuals but also determine how closely related they are Pair unrelated individuals to produce offspring – Mating unsuccessful – discover why female cannot become pregnant or analyze semen of partner Goal of such inbreeding – return endangered species to their natural habitats – enough suitable habitat remaining in wild to support these plants and animals Where do we go from here? Decisions made will depend on clear understanding of science and technology involved as well as people’s beliefs