Chapter Intro-page 336 Learning Goals: Evaluate the importance of plant and animal breeding to humans. Summarize the steps used to engineer transgenic organisms. Analyze how mapping the human genome is benefitting human life.
13.1 Section Objectives – page 337 Section Objectives: • Predict the outcome of a test cross. • Evaluate the importance of plant and animal breeding to humans.
Learning Goal: Evaluate the importance of plant and animal breeding to humans. Summarize the steps used to engineer a transgenic organism
13-1 Applied Genetics • Selective Breeding:Allowing only animals with desired traits to reproduce.
Selective Breeding In 1947, an average milk cow produced 4997 pounds of milk per year. In 1997, 50 years later, an average milk cow produced 16 915 pounds of milk per year
Hybridization • Crossing (reproducing) different individuals to bring together the best of both organisms • Produce a Hybrid which are often hardier than parents.
Inbreeding • Breeding of individuals with similar characteristics to maintain these characteristics
Test Cross • Cross of an individual with unknown genotype with an individual with known genotype • Used to determine genotype
? x dd d d d d D D D d Dd Dd Dd Dd Dd Dd dd dd Heterozygous Homozygous domimant
Learning Goal: • Summarize the steps used to engineer transgenic organisms. • Give examples of applications and benefits of genetic engineering.
13-2: Recombinant DNA Technology Scientists use our knowledge of DNA to study and change it! Genetic Engineering: making changes in the DNA of living organisms • DNA Extraction – taking DNA out of the cell • Restriction enzymes: are special enzymes that cut DNA in specific locations • Gel electrophoresis: DNA is separated and analyzed Some tools we use to change DNA:
4. PCR (polymerase chain reaction): making COPIES of a particular gene that is CUT (by restriction enzymes) out of the original DNA PCR animation • 5. Cutting and Pasting: we can make new DNA by combining DNA from different sources this is called Recombinant DNA Description: DNA polymerase (blue) makes many copies of DNA (red) in a cycle of the polymerase chain reaction (PCR).
Section 13.2 Summary – pages 341 - 348 Cut • What is…? • recombinant DNA • transgenic organism • restriction enzyme • plasmid Cleavage Insertion
Plasmid Plasmids are circular DNA molecules that are separate from the chromosomal DNA . They usually occur in bacteria
Action of Restriction Enzyme
Gel Electrophoresis Unique pattern created by the movement of the DNA through the gel- can identify an individual DNA
DNA Fingerprinting • Help Jimmy Sweet solve his candy mystery! • Who did it? Click to Solve
Transformation – a cell takes & incorporates DNA from outside into its own DNA
Steps to Transforming Bacteria • Take the gene of interest out of the DNA from a human cell • Cut it out using restriction enzymes (act like scissors!!) • You are left with your “gene of interest” • Take a plasmid (ring of DNA) out of a bacterial cell, cut it with restriction enzymes. • Place the gene of interest in the plasmid, making a ring again • Put this ring back into a bacteria and let it reproduce!! Vector
Cleave DNA Restrictive enzyme When the same sequence of bases is found on both DNA strands, but in opposite orders, it is called a palindrome EcoRI enzyme
Transforming Plant Cells • A bacterium inserts a DNA plasmid into plant cells to create new unique plants • Ex. Plants resistant to pesticides
Transforming Animal Cells • DNA is injected into the nucleus of an egg. As the embryo grows the new DNA will be reproduced
Bellwork: Many scientists consider genetic engineering to be simply an effective method of selective breeding. Explain. Today’s Goal: Analyze how genetic engineering and mapping the human genome will benefit future generations.
Biotechnology Review Gel Electrophoresis PCR- Polymerase Chain Reaction Today’s Goal: Analyze how genetic engineering and mapping the human genome will benefit future generations.
Biotechnology • New technology has created a new field of study: Biotechnology • We can create transgenicorganisms – that contain genes from other organisms Glowing bumblebee: Modified Piglets!
Transgenic Animals • Have been used to study genes and improve the food supply • Research is under way where goats could be modified to produce spider silk proteins in their milk that could be used in the production of medical sutures and bullet-proof vests
Transgenic Plants • Modified plants are important in our food supply! • 25% of all corn grown in US in genetically modified • Ex. They have natural insecticides, resist herbicides, vitamins 86%
Recombinant DNA • DNA produced by combining DNA from different sources. • Genetically engineered cells contain recombinant DNA Firefly gene + tobacco plant = glowing tobacco plant!
Cloning Mimi Click and Clone! Genetic Science Learning Center, "Permissions Policy," Learn.Genetics, 29 April 2009, <http://learn.genetics.utah.edu/gslc/permissions.html> (29 April 2009)
13.3- Human Genome Project • When: Began in 1990, finished in 2003 • Cost: approx. $3 billion • What: Sequenced the human genome (all 24 chromosomes) • Why: To help understand our DNA • Fun fact: • The order of almost all (99.9%) nucleotide bases is exactly the same in all people
Applications of Biotechnology Complete the following data table to review the benefits of Biotechnology
Q.P.S. Update Goal: Evaluate the importance of plant and animal breeding to humans.
Bellwork: Place Selective Breeding lab in the collection folder. • What is selective breeding? Today’s Goal: Describe the effect selective breeding will have on the human population.
1. What effect might selective breeding of plants and animals have on the size of Earth’s human population? Why?
2. Using the corn experiment, explain what happened to farmers crops after many years of only choosing the best seeds? Why would you want to use selective breeding?
3. • Using David O Conover’s fish experiment, compare and contrast the tanks that had fish getting smaller vs. larger? • How does this explain selective breeding?
4. • Selective breeding has many benefits but is not without problems. • Create a T-chart of the pros and cons of selective breeding.
Summary: • Become familiar • Model Recombinant DNA • Review and give examples of applications via 13.2 Guided Notes