Frontiers of BiotechnologyFrontiers of Biotechnology

Changing the Living WorldChanging the Living World

• These dogs are all of These dogs are all of the same speciesthe same species

• Where do their Where do their striking differences in striking differences in appearance come appearance come from?from?

Beef Cattle BreedsBeef Cattle Breeds

Selective BreedingSelective Breeding

• A method of improving a species by A method of improving a species by allowing only those individual organisms allowing only those individual organisms with desired characteristics to produce the with desired characteristics to produce the next generationnext generation– Nearly all domestic animals and crop plants Nearly all domestic animals and crop plants

have been produced by selective breedinghave been produced by selective breeding

Luther BurbankLuther Burbank

• American botanistAmerican botanist1849 – 19261849 – 1926

• Developed more than Developed more than 800 varieties of plants 800 varieties of plants in his lifetimein his lifetime– Developed disease Developed disease

resistant potato to help resistant potato to help fight Irish potato blightfight Irish potato blight

HybridizationHybridization

• Breeding technique Breeding technique that involves crossing that involves crossing dissimilar individuals dissimilar individuals to bring together the to bring together the best traits of both best traits of both organismsorganisms

InbreedingInbreeding

• The continued The continued breeding of breeding of individuals with individuals with similar characteristicssimilar characteristics– Breeds developed Breeds developed

through inbreeding are through inbreeding are genetically similargenetically similar

– Increased chances of Increased chances of bringing together two bringing together two recessive alleles for recessive alleles for genetic defectsgenetic defects

Increasing VariationIncreasing Variation

• Breeders can increase genetic variation in a Breeders can increase genetic variation in a population bypopulation by– Inducing mutationsInducing mutations

• Mutations are the ultimate source of genetic variability

Variation – New Kinds of Variation – New Kinds of BacteriaBacteria

• Mutation rates increased by using radiation Mutation rates increased by using radiation or chemicalsor chemicals– Increases the chances of producing a useful Increases the chances of producing a useful

mutantmutant

• Hundreds of useful bacterial strains have Hundreds of useful bacterial strains have been producedbeen produced

Variation – New Kinds of PlantsVariation – New Kinds of Plants

• Polyploid plantsPolyploid plants– Plants with double or triple the normal number Plants with double or triple the normal number

of chromosomesof chromosomes– Produced by using drugs that prevent Produced by using drugs that prevent

chromosomes from separating during meiosischromosomes from separating during meiosis

Manipulating DNAManipulating DNATools of Molecular BiologyTools of Molecular Biology

• DNA extractionDNA extraction– DNA can be extracted from cells by simple chemical DNA can be extracted from cells by simple chemical

proceduresprocedures

• Cutting DNACutting DNA– DNA can be cut into smaller fragments by the use of DNA can be cut into smaller fragments by the use of

restriction enzymesrestriction enzymes

• Separating DNA Separating DNA – Gel electrophoresis – procedure used to produce DNA Gel electrophoresis – procedure used to produce DNA

“fingerprints”“fingerprints”

Cell TransformationCell Transformation

• During transformation, a cell takes in DNA During transformation, a cell takes in DNA from outside the cellfrom outside the cell– External DNA becomes a part of the cell’s DNAExternal DNA becomes a part of the cell’s DNA

Transforming BacteriaTransforming Bacteria

Transforming Plant CellsTransforming Plant Cells

Transforming Animal CellsTransforming Animal Cells

• Can be transformed in Can be transformed in some of the same some of the same ways as plant cellsways as plant cells

• Has applications in Has applications in gene replacement gene replacement therapytherapy

Applications of Genetic Applications of Genetic EngineeringEngineering

• Transgenic organismsTransgenic organisms– Transgenic organisms contain genes from other Transgenic organisms contain genes from other

organismsorganisms• Transgenic microorganismsTransgenic microorganisms

• Transgenic animalsTransgenic animals

• Transgenic plantsTransgenic plants

CloningCloning

• CloneClone• A member of a population of genetically identical A member of a population of genetically identical

cells produced from a single cellcells produced from a single cell

Cloning DollyCloning Dolly

A donor cell is taken from a sheep’s udder. A donor cell is taken from a sheep’s udder.

The nucleus of this cell will provide the genetic The nucleus of this cell will provide the genetic material for the cloned lamb.material for the cloned lamb.

An egg cell is taken from a second sheep. An egg cell is taken from a second sheep.

The nucleus of the cell is removed. The nucleus of the cell is removed.

This cell does not supply any genetic material for This cell does not supply any genetic material for the cloned lamb.the cloned lamb.

The donor cell (with a nucleus) and the egg cell The donor cell (with a nucleus) and the egg cell (without a nucleus) are fused using an electric shock.(without a nucleus) are fused using an electric shock.

The fused cells begin dividing normally, The fused cells begin dividing normally, forming an embryo. forming an embryo.

The embryo is placed in the uterus of a foster The embryo is placed in the uterus of a foster mother.mother.

The embryo develops into a lamb, Dolly. The embryo develops into a lamb, Dolly.

Dolly is a clone of the sheep that donated the udder Dolly is a clone of the sheep that donated the udder cell.cell.

A cross between dissimilar individuals to bring A cross between dissimilar individuals to bring together their best characteristics is calledtogether their best characteristics is called

a. genetic engineeringa. genetic engineering

b. inbreedingb. inbreeding

c. hybridizationc. hybridization

d. sequencingd. sequencing

Crossing individuals with similar characteristics so Crossing individuals with similar characteristics so that those characteristics will appear in the offspring that those characteristics will appear in the offspring is calledis called

a. inbreeding a. inbreeding

b. electrophoresisb. electrophoresis

c. hybridizationc. hybridization

d. genetic engineeringd. genetic engineering

Varieties of purebred dogs are maintained by Varieties of purebred dogs are maintained by

a. selective breedinga. selective breeding

b. hybridizationb. hybridization

c. inbreedingc. inbreeding

d. genetic engineeringd. genetic engineering

Changing the DNA of an organism is calledChanging the DNA of an organism is called

a. genetic engineeringa. genetic engineering

b. hybridizationb. hybridization

c. selective breedingc. selective breeding

d. inbreedingd. inbreeding