chapter 13 genetics and biotechnology 13.1 applied genetics

Chapter 13 Genetics Chapter 13 Genetics and Biotechnologyand Biotechnology

13.1 Applied Genetics13.1 Applied Genetics

Selective BreedingSelective Breeding

The process by which desired traits of The process by which desired traits of certain plants and animals are selected certain plants and animals are selected and passed on to their future generations and passed on to their future generations is called selective breeding.is called selective breeding.


Hybridization is crossing parent organisms Hybridization is crossing parent organisms with different forms of a trait to produce with different forms of a trait to produce offspring with specific traits.offspring with specific traits.

Hybrid organisms can be bred to be more Hybrid organisms can be bred to be more disease-resistant, to produce moredisease-resistant, to produce more offspring, or to grow faster.offspring, or to grow faster.

A disadvantage of hybridization is that it is A disadvantage of hybridization is that it is time consuming and expensive.time consuming and expensive.


Specific traits in Specific traits in breeds can be breeds can be maintained by maintained by inbreeding (breeding inbreeding (breeding two closely related two closely related organisms)organisms)

Clydesdale horses Clydesdale horses have been inbred to have been inbred to retain the desired retain the desired traits: strength, agility, traits: strength, agility, and obedient natureand obedient nature


Disadvantages of Disadvantages of inbreeding is that inbreeding is that harmful recessive harmful recessive traits can also be traits can also be passed to future passed to future generationsgenerations

German Shepherd hip dysplasia

Test CrossTest Cross

A test cross A test cross involves breeding involves breeding an organism that an organism that has the unknown has the unknown genotype (PP or genotype (PP or Pp) with one that is Pp) with one that is homozygous homozygous recessive (pp) for recessive (pp) for the desired traitthe desired trait


13.2 DNA Technology13.2 DNA Technology

Genetic EngineeringGenetic Engineering

Technology that Technology that involves manipulating involves manipulating the DNA of one the DNA of one organism in order to organism in order to insert the DNA of insert the DNA of another organism, another organism, called exogenous called exogenous DNA.DNA.


Production of human Production of human insulin by bacteria insulin by bacteria was one of the first was one of the first commercially commercially successful uses successful uses genetic engineering genetic engineering technology.technology.


Genetically engineered organisms are used:Genetically engineered organisms are used:1.1. to study the expression of a particular to study the expression of a particular

gene.gene.2.2. to investigate cellular processes.to investigate cellular processes.3.3. to study the development of a certain to study the development of a certain

disease.disease.4.4. to select traits thatto select traits that might be beneficialmight be beneficial

to humans.to humans.


Many bizarre and Many bizarre and interesting uses for interesting uses for genetic engineering genetic engineering technologies have technologies have been reported.been reported.

DNA ToolsDNA Tools

An organism’s An organism’s genomegenome is the total DNA in is the total DNA in the nucleus of each cell.the nucleus of each cell.

DNA tools can be used DNA tools can be used to manipulate DNA and toto manipulate DNA and to isolate genes from the isolate genes from the rest of the genome.rest of the genome.

DNA ToolsDNA Tools

Restriction Enzymes are proteins used to Restriction Enzymes are proteins used to cut DNA at specific sequences in specific cut DNA at specific sequences in specific ways.ways.

Restriction enzymes are naturally present Restriction enzymes are naturally present in bacteria to cut and thus restrict foreign in bacteria to cut and thus restrict foreign DNA from interfering with the bacterial DNA from interfering with the bacterial DNA DNA

Restriction EnzymesRestriction Enzymes

EcoRIEcoRI specifically specifically cuts DNA containing cuts DNA containing the sequence the sequence GAATTC.GAATTC.

The ends of the DNA The ends of the DNA fragments, called fragments, called sticky ends, contain sticky ends, contain single-stranded DNA single-stranded DNA that is that is complementary.complementary.

Restriction EnzymesRestriction Enzymes

Gel ElectrophoresisGel Electrophoresis AnAn electric current is used electric current is used

to separate DNA to separate DNA fragments according to fragments according to the size of the fragments the size of the fragments in a process called gel in a process called gel electrophoresis.electrophoresis.

When an electric current When an electric current is applied, the DNA is applied, the DNA fragments move toward fragments move toward the positive end of the the positive end of the gel.gel.

The smaller fragments The smaller fragments move farther faster than move farther faster than the larger ones.the larger ones.

Gel ElectrophoresisGel Electrophoresis

The unique pattern The unique pattern created based on the created based on the size of the DNA size of the DNA fragment can be fragment can be compared to known compared to known DNA fragments for DNA fragments for identification.identification.

Recombinant DNA TechnologyRecombinant DNA Technology

Recombinant DNA is DNA combined from Recombinant DNA is DNA combined from two (or more) sources.two (or more) sources.


1.1. A gene of interest from one organism’s A gene of interest from one organism’s DNA is cut out with a restriction enzyme.DNA is cut out with a restriction enzyme.

2.2. Another organism's DNA is cut open with Another organism's DNA is cut open with the same restriction enzyme.the same restriction enzyme.

3.3. The gene that was cut out is inserted in The gene that was cut out is inserted in the open DNA of the second organism.the open DNA of the second organism.

4.4. Result is a transgenic organismResult is a transgenic organism Easy to insert genes into bacteria; more Easy to insert genes into bacteria; more

difficult with other organismsdifficult with other organisms


To make a large quantity of recombinant plasmid DNA, To make a large quantity of recombinant plasmid DNA, bacterial cells are mixed with recombinant plasmid DNA.bacterial cells are mixed with recombinant plasmid DNA.

Some of the bacterial cells take up the recombinant Some of the bacterial cells take up the recombinant plasmid DNA through a process called transformationplasmid DNA through a process called transformation.

Large numbers of Large numbers of identical bacteria, eachidentical bacteria, each containing the insertedcontaining the inserted DNA molecules, canDNA molecules, can be produced through abe produced through a process called cloning.process called cloning.


To understand how To understand how DNA is sequenced, DNA is sequenced, scientists mix an scientists mix an unknown DNA unknown DNA fragment, DNA fragment, DNA polymerase, and polymerase, and the four nucleotidesthe four nucleotides—A, C, G, T in a —A, C, G, T in a tube.tube.


Each nucleotide is Each nucleotide is tagged with a tagged with a different color of different color of fluorescent dye.fluorescent dye.

Every time a Every time a modified modified fluorescent-tagged fluorescent-tagged nucleotide isnucleotide is

incorporated into incorporated into the newly the newly synthesized strand, synthesized strand, the reaction stops.the reaction stops.


The sequencing reaction is complete when the The sequencing reaction is complete when the tagged DNA fragments are separated by gel tagged DNA fragments are separated by gel electrophoresis.electrophoresis.


A technique called the A technique called the polymerase chain polymerase chain reactionreaction (PCR) can (PCR) can be used to make be used to make millions of copies of a millions of copies of a specific region of a specific region of a DNA fragment.DNA fragment.

Uses of Recombinant DNAUses of Recombinant DNA

BiotechnologyBiotechnology

Organisms genetically Organisms genetically engineered by engineered by inserting a gene from inserting a gene from another organism are another organism are called called transgenic transgenic organismsorganisms..

BiotechnologyBiotechnology

Transgenic animals Transgenic animals are produced for are produced for biological research.biological research.

BiotechnologyBiotechnology Transgenic plants are Transgenic plants are

produced to solve produced to solve food or nutritional food or nutritional problemsproblems

Genetically engineered cotton resists insect infestation of the bolls.

Rice plants with increased iron andvitamins could decrease malnutrition.

BiotechnologyBiotechnology Insulin, human growth Insulin, human growth

hormone and substances hormone and substances that dissolve blood clots that dissolve blood clots are made by transgenic are made by transgenic bacteria.bacteria.

Transgenic bacteria slow Transgenic bacteria slow the formation of ice the formation of ice crystals on crops to crystals on crops to protect them from frost, protect them from frost, clean up oil spills, and clean up oil spills, and decompose garbage.decompose garbage.


13.3 The Human Genome13.3 The Human Genome

The Human Genome ProjectThe Human Genome Project

International Project to sequence the International Project to sequence the entire approximately three billion entire approximately three billion nucleotides that make up the human nucleotides that make up the human genome.genome.

Began in 1990 and completed in 2003; Began in 1990 and completed in 2003; ahead of schedule and under budget.ahead of schedule and under budget.

Found that less than 2% of all the Found that less than 2% of all the nucleotides in the body code for all of the nucleotides in the body code for all of the approximately 100,000 proteins in the approximately 100,000 proteins in the body.body.

DNA FingerprintingDNA Fingerprinting

Using noncoding sequences that are unique to Using noncoding sequences that are unique to each individual (except identical twins), each individual (except identical twins), scientists can identify individuals by their DNA.scientists can identify individuals by their DNA.

Any cell of the body can be used since all cells Any cell of the body can be used since all cells have the same DNA (except red blood cells that have the same DNA (except red blood cells that do not have a nucleus).do not have a nucleus).

The amount of DNA is magnifed by PCR, then The amount of DNA is magnifed by PCR, then cut with restriction enzymes and separated by cut with restriction enzymes and separated by gel electrophoresis.gel electrophoresis.

DNA FingerprintingDNA Fingerprinting

Banding patterns are Banding patterns are unique to each unique to each personperson

Used to identify Used to identify suspects and victims suspects and victims in a crime, determine in a crime, determine paternity, and identify paternity, and identify soldiers killed in war.soldiers killed in war.

Also used to Also used to determine determine evolutionary evolutionary relationshipsrelationships

Identifying GenesIdentifying Genes

After sequencing the DNA the next step is After sequencing the DNA the next step is identifying genes.identifying genes.

Originally thought that humans had Originally thought that humans had 100,000 genes because we have 100,000 100,000 genes because we have 100,000 proteins (one gene-one protein)proteins (one gene-one protein)

Now know that we have 20,000-25,000 Now know that we have 20,000-25,000 genes.genes.

Complicated analysis that uses Complicated analysis that uses information from other genomes DNA information from other genomes DNA sequences along with computer algorithmssequences along with computer algorithms

Bioinformatics and DNA Bioinformatics and DNA MicroarraysMicroarrays

Bioinformatics is a field of study creates Bioinformatics is a field of study creates and maintains databases of biological and maintains databases of biological information.information.

DNA microarrays are tiny microscope DNA microarrays are tiny microscope slides or silicon chips which contain the slides or silicon chips which contain the genes of an organism (a few genes or the genes of an organism (a few genes or the whole genome).whole genome).

The Genome and Genetics The Genome and Genetics DisordersDisorders

More than 99% of an individuals DNA More than 99% of an individuals DNA sequence is the same as any other sequence is the same as any other individual.individual.

Some of the differences that exist are a Some of the differences that exist are a result of a mutation to cause a genetic result of a mutation to cause a genetic disorder.disorder.

HapMap project seeks to identify common HapMap project seeks to identify common genetic variation that occur in humans.genetic variation that occur in humans.

The Genome and Genetics The Genome and Genetics DisordersDisorders

Pharmacogenomics is the study of how Pharmacogenomics is the study of how genetic inheritance affects the body’s genetic inheritance affects the body’s response to drugs. response to drugs.

Gene therapy is a technique used to Gene therapy is a technique used to correct mutated genes.correct mutated genes. Viruses are used as a vector to insert the Viruses are used as a vector to insert the

“good” gene into the patients cells“good” gene into the patients cells All gene therapy trials stopped in 2003 due to All gene therapy trials stopped in 2003 due to

a death caused by a reaction to virusa death caused by a reaction to virus

Genomics and ProteomicsGenomics and Proteomics

Studying the genome Studying the genome is genomics.is genomics. Genes are storage Genes are storage

unitsunits

Proteomics is the Proteomics is the study of the structure study of the structure and function of and function of human proteins.human proteins. Proteins are machines Proteins are machines

of the cellof the cell

chapter 13 genetics and biotechnology 13.1 applied genetics

Documents

organisms dna

open dna

exogenous dna

total dna

foreign dna

known dna fragments

singlestranded dna

parent organisms