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4-1
Biotechnology
 Biotechnology refers to various techniques that use living organisms to make
products or provide services
 Alter normal genetic make-up of organisms, including viruses, bacteria, plants,
animals
 Breeding dogs – with certain desired traits produces offspring with similar traits =
selective breeding
Biotechnology through the ages
 Early 2000 B.C.E – related to food production
 Selectively mating individual animals and plants with desirable characteristics –
early farmers slowly created new genetic combinations
 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 – help from yeast
 Today – reproductive technology – directly altering the genetic material in cell’s
nucleus in order to obtain a desired outcome
 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 – genetic information contained in structure called deoxyribonucleic acid
(DNA)
 Material that chromosomes are made of
 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 – paper cutouts of large model of DNA
(spiral staircase)
 1967 – Har Gobind Khorana and Marshall Nirenberg – genetic code – chemicals
encolded by each part of gene
 1973 – Stanley Cohen and Herbert Boyer – first transfer of genes between species
 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
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Importance of DNA
 Cells rely on coded information to tell them what to do – instructions are
contained in molecules of DNA
 Called nucleic acid because it is found in cell nuclei and is acidic
 Chromosomes are also found in nucleus – made of tightly coiled DNA
 Nucleotide base A is always bonded to TY and C is always bonded
Proteins and DNA
 Messages in DNA are spelled out in a code made up of 3 consecutive bases along
one strand of DNA
 Each segment of 3 consecutive bases = codon
 One of most important messages carried out by DNA – proteins – most of the
structure of cells and tissues in plants and animals
 Each protein – large molecule made up of thousands of smaller molecules called
amino acids
 20 different amino acids and can be combined in different ways to make different
proteins
 Gene – segment of DNA with enough codons to produce all the amino acids to
make one protein
Mutations
 DNA controls the characteristics of a cell – copied before a cell reproduces
 Sometimes mistakes occur – called mutations
 Mistake in sequence of coding for assembling amino acids into a protein –
different protein or property of protein may be made
 Can be inherited – useful, harmful, or have no effect on organism or cell in which
it occurred
 Mutation in body cell of multicellular organism will have less drastic of an effect
than that of a developing embryo
 Most common cause of mutations – mutagenic agents such as radiation,
temperature extremes or exposure to chemicals such as pesticides
 Alter DNA code – cell produce wrong protein or none at all
 Others – cause to lose control of cell division = rapidly and repeatedly producing
cancer
 Chromosomal mutations – occur after chromosomes broken by agents
 Chromosomal mutations in reproductive cells – not survive because egg or sperm
become incapable of fertilization
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 = transgenic organism
 Results will produce changes in characteristics in organism
 May be new protein for human insulin
 Began in 1970’s – bacteria Escherichia coli
 Took advantage of features of bacteria to develop new combinations of genetic
material = recombinant DNA
 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 = gene splicing
 Naturally occurring enzymes are used to cut strands of DNA at specific places –
800 enzymes identified
“Designer Genes”?
 Average – takes 12 years to develop a new plant variety through selective
breeding
 Genetic engineering – new varieties can be made in as little as one year
 Also allows scientists to give organisms genes from other species which selective
breeding cannot
 Crop plants – goal is to make plants that produce more grain that is more
nutritious, resistant to disease-causing viruses or drought
 Livestock – produce leaner meat, more milk, eggs, resistant to disease
 Medicine – gene that is absent in a person may be supplied through genetic
engineering
Cloning
 Production of identical copies of molecules, genes, cells, or entire organisms
 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
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Biotechnology and Human Body
 3000 known diseases linked to genes and scientists can diagnose more than 200 of
them
 Genetic disease – caused by a defect in person’s DNA
 May result from mutation or due to missing or extra gene or chromosome
 May lead to physical or physiological disorders
 Genetic screening – looking at a magnified image of person’s chromosomes
 Picture of cell’s chromosome – karyotype
 Gene therapy – allows scientists to replace defective genes with healthy ones
 One method – uses an altered virus
 Virus normally attacks cells by attaching to cell’s outer membrane and then
pushing its own DNA into cell – viral DNA uses the host cell to make copies of
itself
 Altered virus – splice a healthy gene into viral DNA and let virus transfer the
gene into patient’s cells
 Gene therapy using somatic cells can help inherited diseases
 Avoid passing on disease to offspring, defective genes need to be located and
altered in patient’s sex cells
 All genes found in complete set of chromosomes – genome
 Mapping entire human genome – provide ideal tool for diagnosing genetic
disorders
 Human Genome Project – 1990 in USA, locating approximately 100 000 genes
that are found in one set of 23 human chromosomes
 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 – disease that affects
pancreas and lungs
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)
 Hormone can be produced in bacteria in large quantities and relatively
inexpensive
 Bacteria also used to produce human growth hormone and interferon (protein for
immune system)
 Animals and bacteria – can be given human genes – adding to fertilized eggs or
parents – offspring grow up with human gene
 Advantage of using mammals is that proteins can be collected in mammal’s milk
– do not have to be killed

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Biotechnology in Agriculture
 New crops – always trying to improve crop production – cross-pollination of 2
strains of crop by hand in order to crate a new combined variety = hybrid
 Cropbreeders can now select a specific genetic trait from one species and move it
into the genetic code of a crop plant
 Allows breeders to choose the particular genetic characteristics they want
 Gives breeders the alternative of using genes from unrelated species (including
animals or micro-organisms) as well as plants
 Wheat variety – may contain a gene that allows it to resist a specific pest –
transferred to different species of plants
 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 – Canadian and oil
 Ancestor is a plant called rapeseed – used in Asia and Europe in lamps, for
cooking, in foods
 Today – seeds contain the highly desirable oil used in shortening, salad oil,
cooking spray, printing ink, hydraulic fluids, suntan lotion
 Rapeseed grown in Canada since 1936 – high demand during WWII as one or
most effective lubricants for metal engine parts
 Edible rapeseed oil extracts were first put to use on market 1956-57
 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 – situation where large parts of a country are planted with a single
variety of a crop or limited number of varieties – prone to large-scale destruction
by single pest or disease
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) – controls calf growth and milk production –
cows injected with this hormone can produce more milk
 Must be injected regularly into cows to see benefits
 Concerns – using the hormone might increase chances of some types of infection
in cows
 Increase costs of antibiotics, veterinarians, nutritionists are more cost-effective on
large-scale farm operations with many cows producing increased revenue
 In 1999 – federal government did not approve use of BGH for milk production in
Canada
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Biotechnology in the Environment
 How to clean up toxic wastes left over – carelessness or released into environment
by accident or negligence
 Canada – might have to spend billions of dollars for environmental clean-up
 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 = bioremediation
 Decomposers (bacteria, fungi, micro-organisms) use dead plant and animals as
food
 Different species of these – break down and decompose almost anything
including chemicals that are toxic to humans
 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 – oil tanker released 42 million liters of crude oil – killed
thousands of animals
 33 000 sea birds, 146 bald eagles, 980 sea otters had been found dead
 Oil covered 1600km of shoreline
 To remove oil – used steam, towels, oil-eating bacteria were spread on shoreline
with nitrogen and phosphorus fertilizers to aid in growth
 Between 1976 and 1987 – over 300 significant oil spills occurred off Canada’s
east and west coasts
 1988 – Washington state – spilled 875t of oil which drifted up to Vancouver
Island – killed 46 000 shorebirds
 Mercury, copper, zinc, lead – result in damage to nervous, circulatory, digestive
and reproductive systems of humans
 Released into environment by industrial and mining activities, urban storm runoff, leaching of rocks and soil by acid rain
 Micro-organisms may prove useful in gathering heavy metal pollutants
 Bacteria, fungi, algae – use metals in soil or rocks to produce energy
 Cabbage, mustards, radishes – can concentrate heavy metals in their roots
 These plants can be genetically altered to take up specific metals from the soil
 Plants do not remove them, they just concentrate the metals
 Plants must be harvested and then disposed safely to remove pollutants
Species Preservation
 Overfishing, pollution, global climate change – reduce diversity of marine life
throughout the world
 Oceans – organisms have unique biochemical characteristics that provide
opportunities for solving a variety of medical problems
 Bacterium that lives with sponges and sea squirts – chemicals that kill viruses
 Compound found in deep-sea bacterium – used to inhibit HIV virus
 Many sponges and corals – make chemicals that reduce inflammation and pain of
acute asthma, arthritis and injuries
 Other marine organisms – antibiotics and antibodies
 Biotechnology can also be used to preserve some endangered species
 Bred in captivity to increase numbers
 Inbreeding – mating 2 closely related individuals may increase chance of genetic
diseases, offspring less genetically variable from those mating of non-related
parents
 Solution – DNA fingerprinting – identify individuals but also determine how
closely related they are
 Pair unrelated individuals to produce offspring – selective breeding to maintain
genetic variation
 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?
 Food you eat, treatment of disease, well-being of your children, environment in
which you live will be determined by what happens in biotechnology
 Decisions made will depend on clear understanding of science and technology
involved as well as people’s beliefs