Lesson 5Lesson 5

Using Crossbreeding and Using Crossbreeding and HybridsHybrids

Next Generation Science/Common Core Standards Addressed!Next Generation Science/Common Core Standards Addressed!

HS‐LS1‐1. Construct an explanation based on evidence for how the structure of HS‐LS1‐1. Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells. [Assessment Boundary: Assessment does life through systems of specialized cells. [Assessment Boundary: Assessment does not include identification of specific cell or tissue types, whole body systems, not include identification of specific cell or tissue types, whole body systems, specific protein structures and functions, or the biochemistry of protein synthesis.]specific protein structures and functions, or the biochemistry of protein synthesis.]

Agriculture, Food and Natural Resource Agriculture, Food and Natural Resource Standards Addressed!Standards Addressed!

PS.03.01. Demonstrate plant propagation techniques in plant system PS.03.01. Demonstrate plant propagation techniques in plant system activities.activities.

PS.03.01.03.a. Summarize optimal conditions for asexual propagation and demonstrate PS.03.01.03.a. Summarize optimal conditions for asexual propagation and demonstrate techniques used to propagate plants by cuttings, division, separation, layering, budding techniques used to propagate plants by cuttings, division, separation, layering, budding and grafting.and grafting.

Bell WorkBell Work

Define Plant BreedingDefine Plant Breeding Define the processes of selection and Define the processes of selection and

hybridizationhybridization Explain genetic engineering in plantsExplain genetic engineering in plants

TermsTerms

Agrobacterium Agrobacterium TumefaciansTumefacians

Ballistic Gene Ballistic Gene TransferTransfer

CultivarCultivar Genetic EngineeringGenetic Engineering GenotypeGenotype Hybrid vigorHybrid vigor HybridizationHybridization

MicroprojectilesMicroprojectiles MutationMutation PhenotypePhenotype Plant BreedingPlant Breeding SelectionSelection TotipotentTotipotent Transgenic plantsTransgenic plants

Interest ApproachInterest Approach

Ask the students to tell you what they have Ask the students to tell you what they have heard about genetically modified organisms heard about genetically modified organisms (GMO). Make a list of these items on the board. (GMO). Make a list of these items on the board. Discuss these items briefly. Discuss these items briefly.

Ask the students to make a copy of this list. Tell Ask the students to make a copy of this list. Tell them that you will take another look at the items them that you will take another look at the items on this list after you have completed the unit. on this list after you have completed the unit.

At that time, ask what the students know about At that time, ask what the students know about GMO’s now. What items changed?GMO’s now. What items changed?

What is plant breeding?What is plant breeding?

Plant breedingPlant breeding is the systematic process is the systematic process of improving plants using scientific of improving plants using scientific methods.methods.

There are a variety of methods used to There are a variety of methods used to make certain plants are pollinated, as well make certain plants are pollinated, as well as methods to prevent unwanted as methods to prevent unwanted pollination of plants.pollination of plants.

The goals of plant breeding vary according to The goals of plant breeding vary according to the type of improvement in the plant that is the type of improvement in the plant that is desired by the plant breeder. Examples;desired by the plant breeder. Examples;

Gain disease resistanceGain disease resistance Gain insect resistanceGain insect resistance Improve environmental adaptationImprove environmental adaptation Improve productivityImprove productivity Make a species more suited to cultural practicesMake a species more suited to cultural practices Obtain a more desirable product from plantsObtain a more desirable product from plants

The The genotypegenotype is the is the genetic makeup of a genetic makeup of a plantplant

Plant breeders are Plant breeders are continually looking for continually looking for new plant genotypes new plant genotypes that will produce desired that will produce desired resultsresults

PhenotypePhenotype

Phenotype is the Phenotype is the outward or physical outward or physical appearance of a appearance of a plantplant

Changes in Changes in genotype often genotype often result in a change result in a change in phenotype also.in phenotype also.

Plant breeders often develop new Plant breeders often develop new plant cultivarsplant cultivars

A cultivar is a cultivated plant that has A cultivar is a cultivated plant that has specific and distinguishable specific and distinguishable characteristics.characteristics.

Plants within a cultivar will retain the Plants within a cultivar will retain the characteristics of that group when characteristics of that group when reproduced.reproduced.

What are selection and What are selection and hybridization?hybridization?

SelectionSelection is process of breeding plants is process of breeding plants that are selected for a particular that are selected for a particular characteristic.characteristic. Selection leads to dominance of certain Selection leads to dominance of certain

genetic traitsgenetic traits A A mutationmutation is a genetic variation that naturally is a genetic variation that naturally

occurs in the plantoccurs in the plant Mutations cannot be predictedMutations cannot be predicted

HybridizationHybridization is the process of breeding is the process of breeding individuals from distinctly different varietiesindividuals from distinctly different varieties Goal is gain a superior characteristic in the Goal is gain a superior characteristic in the

offspring.offspring. Hybrid vigorHybrid vigor is a condition where the offspring is a condition where the offspring

may have a greater yield, height, disease may have a greater yield, height, disease resistance, or other traits than either of the resistance, or other traits than either of the parents.parents.

How is genetic engineering How is genetic engineering accomplished in plants?accomplished in plants?

Genetic engineeringGenetic engineering is the process of is the process of altering an organisms by deliberately altering an organisms by deliberately changing the DNA.changing the DNA.

Transgenic plantsTransgenic plants is the plants into which is the plants into which genes from another organism have been genes from another organism have been incorporated.incorporated.

To genetically modify an entire plant, the To genetically modify an entire plant, the initial transfer of genetic information occurs at initial transfer of genetic information occurs at the single cell level.the single cell level.

Aided by the fact that plants are totipotent.Aided by the fact that plants are totipotent. Totipotent means that an organism has the ability Totipotent means that an organism has the ability

to grow from a single cell.to grow from a single cell.

There are two common practices There are two common practices of moving genetic informationof moving genetic information

Agrobacterium tumefaciansAgrobacterium tumefacians is a is a bacterium that causes a disease known as bacterium that causes a disease known as crown gall in plants.crown gall in plants. Bacterium infects the plant by transferring its Bacterium infects the plant by transferring its

genetic material into the plant cellgenetic material into the plant cell Accomplished by moving the plasmid DNA of Accomplished by moving the plasmid DNA of

the bacteria into an injured site on the plantthe bacteria into an injured site on the plant

Ballistic gene transferBallistic gene transfer is the use of tiny is the use of tiny DNA-coated projectiles as carriers (used DNA-coated projectiles as carriers (used when agrobacterium tumefacians are not when agrobacterium tumefacians are not effective)effective) Used to transport DNA through the walls of Used to transport DNA through the walls of

intended recipient cellsintended recipient cells Microprojectiles Microprojectiles are those projectiles and are are those projectiles and are

tiny gold particlestiny gold particles

Success rate is Success rate is from less than from less than 1% to about 10%1% to about 10%

Accomplished Accomplished with a gene gun with a gene gun or microprojectile or microprojectile unitunit

ReviewReview

What is plant breeding?What is plant breeding? What are selection and hybridization?What are selection and hybridization? How is genetic engineering accomplished in How is genetic engineering accomplished in

plants?plants?

The End!The End!