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Transcript
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