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Clone = exact copy, gene, cell or organism that carry identical genetic material because they
are derived form the same original DNA
· Identical twin formed when zygote splits in two (natural clones) Clones in
· Plants can reproduce asexually (producing clones)
· Bacteria split by binary fission (mitosis) Nature
· Asexual Reproduction Advantages Disadvantages
· Quick/rapid reproduction · no genetic variation
· Works where sexual ·Equal susceptibility to disease
reproduction fails
· All offspring have genetic
information to survive in their
· Natural Vegetative propagation in plants
­ English elm can reproduce by basal sprouts after catastrophic events
­ They grow from the root, where least damage will have occurred
­ Advantage ­ root suckers help elm spread
­ Disadvantage ­ no resistance to fungal attack, new root suckers will be ALL affected…read more

Slide 2

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Artificial Vegetative propagation has two main methods
­ Taking cuttings, section cut between nodes and treated with root growth hormones to encourage root growth
­ Grafting ­ shoot section of woody plants (fruit tree) joined to already growing root/stem (rootstock)
­ The graft grows as a clone whilst the rootstock isn't genetically identical
· Artificial propagation using tissue cultures (a more modern approach)
­ Tissue cultures can help to generate large stocks of a valuable plant, these stocks are also guaranteed disease free
· Micropropagation by callus tissue culture
­ Small piece of tissue taken from plant to be cloned, usually from shoot tip, this is the EXPLANT
­ This is grown on a nutrient growth medium
­ Cells in tissue divide, but do not differentiate, form mass of cells called CALLUS
­ After few weeks, single callus cells removed and put on a growth hormone medium to encourage shoot growth
­ Again, after a few further weeks, the growing shoots are placed on a medium that encourages root growth
­ The growing plants are then transferred to a greenhouse to be acclimatised and grown further before being
planted outside
· Advantages
­ Farmers know what crop they are growing in terms of taste, yield and resistance
­ Farmers costs are lowered as all the crop can be harvested at the same time
e s
­ This is a `refinement' of selective breeding
lo n
­ Micropropagation is also much faster than selective breeding
l ltu r e
· Disadvantages
ic i a u
All plants equally susceptible to disease and pests, eg Potato Famine
Same as natural cloning
r t f
i gr i c
A dA
an…read more

Slide 3

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Artificial Cloning in animals ­ two possibilities
Splitting embryos ­ `artificial identical twins'
Cells from developing embryo can be seperated out
Each one can go on to produce a separate, genetically identical organism Animals
­ Used to clone cows, sheep, rabbits and toads, as well as a primate in 2000
· Nuclear Transfer
­ Differentiated cell from an animal is taken
­ Nucleus placed in egg cell which has had it's nucleus removed (enucleated)
­ The egg then develops using genetic information from the inserted nucleus
­ Dolly ­ 1996 ­ cell taken from mammory gland of female sheep, nucleus transplanted into enucleated cell from
second sheep, this was planted into uterus of a third sheep before being placed in a fourth to develop
· Advantages of cloning animals
­ High-value animals can be cloned in large numbers
­ Rare animals can be cloned, preserving the species
­ GM animals that have pharmaceutical chemicals in their milk can be produced quickly
· Disadvantages
­ Some High-value animals do not live in brilliant welfare
­ Genetic uniformity may cause them to not be able to cope well with change
­ Still unclear whether animals from nuclear transfer will remain healthy in the long term
· What is non-reproductive cloning
­ Cloning to generate cells, tissues and organs to replace those damaged by accident or disease
­ Advantages include
­ Less likely to be rejected as they are genetically identical, less pressure on a waiting list for organ transplant
­ Often referred to as therapeutic cloning but many people object to it's use within humas…read more

Slide 4

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Biotechnology ­ industrial use of living organisms to produce food, drugs and other products
· Ancient biotechnology includes yogurt making and brewing
· Modern biotechnology is recombinant DNA techology, with four major applications
1. Healthcare and medical processes 2. Agriculture
3. Industry 4. Food Science
· Use of microorganisms in biotechnology
­ Favourable because microorganisms:
­ Grow rapidly in favourable conditions, double numbers in up to 30 minutes
­ Often produce proteins that can be harvested
­ Can be genetically engineered to produce specific products
­ Grow well at relatively low temperatures
­ Not dependant on climate, thus can be grown worldwide
­ Tend to generate pure products
Purpose Example Organisms involved
Food Cheese Bacterial growth in milk changes taste and texture, whilst preventing other
making bacteria from growing thus acting as a preservative
Drug Penicillin Fungus grown in culture produces antibiotic as a by-product of it's
(antibiotic) metabolism
Enzyme Calcium Fungus produces citric acid as a by-product of metabolism
production citrate
Bioremediation Waste water Variety of bacteria and fungi use organic waste in the water as nutrients and
treatment make the waste harmless
of waste…read more

Slide 5

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The growth curve
· The standard growth curve in a `closed system'
­ Lag phase- Organisms are adjusting to the surroundings, population fairly constant
­ Log phase- population increases exponentially, Every individual has plentiful space and resources
­ Stationary phase ­ Nutrient levels decrease, waste products build up, organism death= organism production
­ Death phase ­ Nutrient exhaustion, toxic levels of waste product, eventually all organisms in the system die
· Fermentation and Fermenters
­ Culturing of microorganisms in fermentation tanks, both aerobically and anaerobically
­ Substances generated by growth of microorganism, separation and purification to obtain the final product
· Metabolism is a process, metabolites are the products
­ Metabolism = sum total of all chemical reactions that occur within an organism
­ Including: new cells and cellular components; chemicals such as hormones; waste products
­ A waste product of one organism's metabolic processes are the vital nutrients required by other organisms
· Primary and secondary metabolites
­ Primary metabolites - substances produced by an organism as part of it's normal growth, including amino acids,
proteins, ethanol and lactate
­ Production of primary metabolites matches growth of the population of the organism
­ Secondary metabolites ­ substances produced but not part of an organisms normal growth, includes antibiotic
­ Production usually starts after main growth period and does not match population growth of an organism
­ Only a relatively small number of microorganisms produce secondary metabolites…read more

Slide 6

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Commercial applications of biotechnology
· Industrial-scale fermenters and `scaling up'
­ Commercial applications usually require growth of a particular microorganism on an enormous scale
­ An industrial-scale fermenter is a he tank with tens of thousands litres capacity
­ Growing can be manipulated and controlled to ensure a good yield
­ Precise conditions depend on the microorganism being cultured and if its primary/secondary metabolite needed
­ Factors include temperature, type and time of addition of nutrient, oxygen concentration and pH
­ Large cultures need `starter' populations, which are initially grown in a sterile nutrient broth
· Batch and continuous culture
­ Batch culture ­ microorganism starter population mixed with specific quantity of nutrient solution
­ Then it is allowed to grow for a fixed amount of time with no additional nutrients
­ At the end of this period the product is removed and fermentation tank is emptied
­ Penicillin is produced like this
­ Continuous culture ­ nutrients added and products removed at regular intervals or continuously
­ Human hormones, such as insulin are produced like this, from genetically modified E.coli
· Asepsis is vital in biotechnological processes involving microorganisms
­ Nutrient medium that culture is grown in could also support life of many unwanted microorganisms
­ Any unwanted microorganism is called a contaminant
­ Unwanted organisms: compete for nutrients and space, reduce yield of useful products, may cause spoilage etc
­ In processes where foods or medicinal chemicals are being produced, contamination renders all product unsafe
­ Aseptic techniques refer to measures taken to ensure asepsis (the absence of unwanted microorganisms)…read more

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