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Genetic Genetic Engineering Engineering & & BiotechnologBiotechnologyy

What we can do with What we can do with genesgenes

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The combination of biology and technology has been making many products better for many years.. . such as bread, cheese, and yogurt by using the best ingredients to make the best products.

This brings about….This brings about….

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Selective Breeding/Genetic Selective Breeding/Genetic ModificationModification

Humans Humans select select animals or plants with animals or plants with desirabledesirable (beneficial) (beneficial) traitstraits and and breed breed themthem

This ensures that many of the This ensures that many of the offspringoffspring will will have desirable traits from both parentshave desirable traits from both parents

This is how we have so many breeds of dogs, This is how we have so many breeds of dogs, horses, cats and foods!horses, cats and foods!

This is also how we have certain fruits and This is also how we have certain fruits and vegetables with certain traitsvegetables with certain traits

Does Does NOTNOT involve actually changing DNA! involve actually changing DNA!

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Examples of selective breedingExamples of selective breeding

meat products have been bred to contain less fat.

fruits and vegetables we consume have been selectively bred to be larger, sweeter, hardier, and even juicier, and resistant to fungus infections.

Known as genetically modified foods

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Genetic EngineeringGenetic Engineering

Technology that humans use to Technology that humans use to alter alter DNADNA or study DNA or study DNA

Examples:Examples:– DNA Fingerprinting (Gel DNA Fingerprinting (Gel

Electrophoresis)Electrophoresis)•Used in paternity testingUsed in paternity testing•Used as evidence in criminal casesUsed as evidence in criminal cases

– DNA RecombinationDNA Recombination•Inserting a gene into bacterial DNAInserting a gene into bacterial DNA•Bacteria will then construct the Bacteria will then construct the protein coded for in that DNAprotein coded for in that DNA

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1. Recombinant DNA Technology

Inserting a gene from one organism into another (usually bacteria)• Ex: Inserting human insulin

gene into bacterium; bacterium will now make insulin for Diabetics

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This is a cheaper way to obtain insulin because it can be produced in greater amounts and there are smaller risks of side effects since the gene making the insulin is a human gene.

Gene therapy video– watch

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Diagram of Recombinant DNAhttp://www.youtube.com/watch?v=-sI5vy-cD2g

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Plasmid– A circular double stranded DNA molecule– Is generally found in Bacteria– Function as vectors for genetic engineering

Vector– Transfers genes from one organism to

another– May contain a genetic marker that codes for

a particular phenotype

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Restriction EnzymesRestriction Enzymes Special enzymes that Special enzymes that recognizerecognize certain certain

DNA basesDNA bases and then actually and then actually cutcut (splice) (splice) the DNA at that locationthe DNA at that location

Used in DNA Fingerprinting and DNA Used in DNA Fingerprinting and DNA RecombinationRecombination

– EXAMPLE:EXAMPLE: EcoRI recognizes GAATTC EcoRI recognizes GAATTC• Will cut at this spot between the G and AWill cut at this spot between the G and A• Creates Creates STICKY ENDSSTICKY ENDS ( (single strandssingle strands of DNA) of DNA)

that can bind to new DNAthat can bind to new DNA

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EcoRI- Commonly used restriction EcoRI- Commonly used restriction enzymeenzyme

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Recombinant DNA: The Video ClipRecombinant DNA: The Video Clip

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2 Gel Electrophoresis /DNA 2 Gel Electrophoresis /DNA fingerprintingfingerprinting

Separates DNASeparates DNA into different into different banding patternsbanding patterns based on what based on what they contain (HOW MANY they contain (HOW MANY BASESBASES IN EACH STRAND!)IN EACH STRAND!)

DNA separates due to DNA separates due to opposite opposite chargecharge at one end of chamber at one end of chamber and how heavy it isand how heavy it is

Makes a “finger-print”Makes a “finger-print” Parents will have similar Parents will have similar banding to their children banding to their children and vice-versa and vice-versa

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Gel Electrophoresis video clip

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3. Paternity tests Using DNA

fingerprinting and electrophoresis to determine the parents of a child.

It is important to remember that the child’s DNA came from both of the parents……50% from mom; 50% from dad…and the DNA fingerprint should reflect this.

Let’s See!

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Benefits of Genetic EngineeringBenefits of Genetic Engineering

1. Making large amounts of a human protein, such as insulin

2. Finding cures by altering DNA3. DNA Fingerprinting has helped us

to see how similar certain organisms are

4. Alter DNA in plants to make them resistant to certain diseases

5. Paternity tests.

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NOVA: The Killer’sTrail (4:45)http://www.pbs.org/wgbh/nova/teachers/body/forensic-dna-analysis.html

Questions for Discussion How was DNA evidence used to prove that Dr. Sam

Sheppard did not murder his wife? Why wasn't this evidence used when the case first went to court?

Why do you think the DQA1 test was chosen for DNA analysis in this case, instead of another, more powerful genetic test?

If the blood trail left at the murder scene wasn't Marilyn's or Sam's, whose blood might it have been?

If you were a juror on this trial, would you be convinced by the DNA evidence?