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B1b 6 Variation. 6.3 Cloning. Learning objectives. What is a clone, and why and how are they created? What are the risks of cloning?. Attack of the Clones. The creation of a genetically identical copy of an existing or previously existing organism Produced asexually
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B1b 6 Variation 6.3 Cloning
Learning objectives • What is a clone, and why and how are they created? • What are the risks of cloning?
Attack of the Clones • The creation of a genetically identical copy of an existing or previously existing organism • Produced asexually • Naturally done by many plants
Cloning Plants • Gardeners have been at it for 100s of years • Ensure that plant has qualities you desire • Spiders plants – produce rooting side branch (stolon) – becomes independent • Take a cutting – stem or leaf • Keep in the correct environment (damp) • Roots are produced • Clone • Commercial technique
Cloning tissue • Tissue culture – produces 1000’s of plants from one cutting • Much more expensive • Small group of cells chemically treated with hormones • Cells reproduce • Grow into a new plant • Guarantees characteristics
Hello Dolly • Dolly the Sheep • Created/born 1996 • From a mammary gland cell • Since then • Monkeys • Cats • Bulls • Horses
Cloning Animals – how? • Embryo transplants A developing embryo is “split” before the cells specialise and the identical embryos are implanted into host mothers.
Cloning animals – how? • Fusion cell cloning • Take egg from one organism • Remove nucleus • Genetic info • Replace DNA • Start cell division • Implant into ‘mother’
Pros and cons • Bring back extinct/endangered animals • Pets or prize animals • Clone animals which produce useful proteins • Medically useful • Reduces variety in a population • If one does have useful mutation, none will • If one has bad mutation, all will • Cloning humans – who would you clone?
Learning outcomes • Genetically identical offspring produced asexually are clones • Easy in plants • Cuttings • Tissue culture • Cloning animals • Embryo transplant • Fusion cloning
Friesian Jersey Hereford Selective breeding I raise cows. Each type of cow is good at a certain job. The Friesian cow produces large quantities of milk, the Jersey cow produces very nice milk and the Hereford cow produces lot of beef. If, for example, I want lots of milk I would only breed Friesian cows with each other – this is SELECTIVE BREEDING.