BioKnowledgy presentation on 3.5 Genetic modification and biotechnology
Genetics 3.5 Genetic modification and biotechnology.
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Transcript of Genetics 3.5 Genetic modification and biotechnology.
Genetics3.5 Genetic modification and biotechnology
Electrophoresis• Gel electrophoresis is
used to separate proteins or fragments of DNA according to size.
• DNA is negatively charged.
• Proteins can be neg or pos charged.
• Eukaryotic DNA must be broken into smaller fragments.
• Exposed to electric field.
• Gel resists movement▫ Smaller DNA segments
move further.
DNA amplification by PCR• PCR can be used to amplify
small amounts of DNA• Many copies made in a short
period of time• Copy specific DNA sequences
not the whole genome▫ Selected by using a primer that
binds to the start of a desired sequence
• Only a small amount needed to start.▫ Why would this be important?
Forensics Fossils
• Data-based question p 188
DNA profiling• DNA profiling involves
comparison DNA• Sequences that are known to
vary considerably between individuals are selected and copied. ▫ Why?
• Copied DNA is cut into fragments with restriction endonucleases (enzymes).
• Fragments separated using gel electrophoresis
• Pattern of bands = DNA profile
Who dunnit?
See Example: page 190
Who is the Daddy?
Genetic Modification
• Genetic modification = The transfer of genes from one species to another▫ Possible because the genetic code is universal
Same amino acid sequence translated Same proteins produced
• Examples: ▫ Producing human insulin using bacteria (see 2.7)▫ Introducing new characteristics to animal species:
goats with spider silk protein in milk.▫ New varieties of crop plants (GM): tomatoes that are
purple.
Genetic engineering• Genetic engineering
= the collective term for the techniques used to transfer genes from one species to another.
• Gene tranfer to bacteria with plasmids using restriction endonucleases and DNA ligase.
Genetic engineering
•Usually easier to obtain mRNA transcripts of genes
•Reverse transcriptase is an enzyme that can make DNA (called cDNA) from RNA
Assessing the risks of genetic modification•Almost everything we do carries risk.•Scientists must assess the risk associated
with their research before carrying it out.▫What is the chance of an accident or other
harmful consequences?▫How harmful would the consequences be?
•Discuss•See p 194 and Data-based question p 195
Clones• Clones: groups of genetically identical
organisms, derived from a single original parent cell.
Natural Methods Human involvmentAsexual reproductionGarlic bulbsStrawberry plantletsHydra buddingAphidsTwins
Plant cuttingsSplitting embryosTransplanted nuclei
Dolly• Activity:
http://teach.genetics.utah.edu/content/tech/cloning/Youve%20Come%20A%20Long%20Way%20Dolly.pdf
• Video: https://www.youtube.com/watch?v=tELZEPcgKkE
• See p 199
Cloning simulation
•http://learn.genetics.utah.edu/content/cloning/clickandclone/