B1b 6 VariationB1b 6 Variation6.3 Cloning6.3 Cloning

Learning objectivesLearning objectives What is a clone, and why and how What is a clone, and why and how

are they created?are they created? What are the risks of cloning?What are the risks of cloning?

Attack of the ClonesAttack of the Clones The creation of a The creation of a

genetically identical genetically identical copy of an existing copy of an existing or previously or previously existing organismexisting organism

Produced asexuallyProduced asexually Naturally done by Naturally done by

many plantsmany plants

Cloning PlantsCloning Plants Gardeners have been at it for 100s of Gardeners have been at it for 100s of

yearsyears Ensure that plant has qualities you desireEnsure that plant has qualities you desire

Spiders plants – produce rooting side Spiders plants – produce rooting side branch (stolon) – becomes independentbranch (stolon) – becomes independent

Take a cutting – stem or leafTake a cutting – stem or leaf Keep in the correct environment (damp)Keep in the correct environment (damp) Roots are producedRoots are produced CloneClone

Commercial techniqueCommercial technique

Cloning tissueCloning tissue Tissue culture – produces Tissue culture – produces

1000’s of plants from one 1000’s of plants from one cuttingcutting Much more expensiveMuch more expensive

Small group of cells Small group of cells chemically treated with chemically treated with hormoneshormones

Cells reproduceCells reproduce Grow into a new plantGrow into a new plant Guarantees characteristicsGuarantees characteristics

Why is a cutting the same as it’s Why is a cutting the same as it’s parent plant?parent plant?

Hello DollyHello Dolly Dolly the SheepDolly the Sheep Created/born 1996Created/born 1996 From a mammary From a mammary

gland cellgland cell Since thenSince then

MonkeysMonkeys CatsCats BullsBulls HorsesHorses

Cloning animals – why?Cloning animals – why?

Cloning Animals – how?Cloning Animals – how?

A developing embryo is “split” before the cells specialise and the identical embryos are implanted into host

mothers.

Embryo transplantsEmbryo transplants

Cloning Cloning animals – animals – how?how? Fusion cell cloningFusion cell cloning1.1. Take egg from one Take egg from one

organismorganism2.2. Remove nucleusRemove nucleus

Genetic infoGenetic info3.3. Replace DNAReplace DNA4.4. Start cell divisionStart cell division5.5. Implant into Implant into

‘mother’‘mother’

Pros and consPros and cons Bring back extinct/endangered animalsBring back extinct/endangered animals

Pets or prize animalsPets or prize animals Clone animals which produce useful Clone animals which produce useful

proteinsproteins Medically usefulMedically useful

Reduces variety in a populationReduces variety in a population If one does have useful mutation, none willIf one does have useful mutation, none will If one has bad mutation, all willIf one has bad mutation, all will

Cloning humans – who would you clone?Cloning humans – who would you clone?

How might fusion/adult cell cloning How might fusion/adult cell cloning be useful?be useful?

Learning outcomesLearning outcomes Genetically identical offspring Genetically identical offspring

produced asexually are clonesproduced asexually are clones Easy in plantsEasy in plants

CuttingsCuttings Tissue cultureTissue culture

Cloning animalsCloning animals Embryo transplantEmbryo transplant Fusion cloningFusion cloning

Selective breedingSelective breedingI 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.

Friesian

Jersey

Hereford

Selective breeding vs. Selective breeding vs. CloningCloning

Advantages Disadvantages

Cloning

Selective breeding