WarmUp 21407 Happy Valentines Day

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Warm-Up 2/14/07Happy Valentines Day ?

• Romeo and Juliet are expecting a baby. Juliet is
  colorblind, but Romeo is not. We know that the
  allele for colorblindness is found on the X
  chromosome. What is the probability that they
  will have a daughter who is colorblind? What is
  the probability that any of their children will
  be colorblind?
• 2. Fathers gen AA- Fathers phen ?
• Mothers gen BO Mothers phen ?
• Offsprings possible genotypes/phenotypes?
  
• 3. Huntingtons Disease follows what pattern of
  inheritance? Tay Sachs disease?

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DNA/Gene Technology

• Chapter 13

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Human Genome

• Linkage map
• Location of genes on a chromosome
• Sequencing
• Entire human genome was completed in 2003
• HUMAN GENOME PROJECT
• Applications
• Diagnosis of disorders
• Gene therapy

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Selective Breeding

• Produces organisms with desired traits
• What are some traits that might be desired by
  breeders in these organisms?

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Inbreeding

• Mating of closely related individuals
• Ensures that offspring remain homozygous for most
  traits
• Keeps wanted traits in the breed
• Keeps out un-wanted traits
• Does have a high risk of offspring receiving 2
  HARMFUL recessive traits
• What might this lead to?

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Hybrids

• Usually produce larger, stronger organisms
• AND VARIATION!
• Mixing dominant recessive keeps out harmful
  recessive phenotypes
• ESPECIALLY IN PLANTS!

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Test Cross

• -Used to
• determine
• unknown
• genotypes

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GENETIC ENGINEERING

• Fast, reliable method for increasing the
  frequency of a specific allele in a population
• Involves cutting (cleaving) DNA from one organism
  inserting into a host organism
• Also called recombinant DNA
• RESULS IN
• TRANSGENIC organisms

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Creating Recombinant DNA

• 1. Cut (cleave) DNA from one organism with a
  restriction enzyme
• 2. Insert (splice) the wanted genes (DNA) from
  another organism (Fig 13.4)
• RESULT
• RECOMBINANT DNA TRANSGENIC ORGANISM
• Usually done on plasmid DNA (bacterial)
  circular DNA

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DNA/GENE TECHNOLOGY

• USE
• genetically engineered vaccines
• increasing agricultural yields
• crops which dont need fertilizer
• gene therapy providing what a bad gene didnt
  correcting genetic disorders
• Use of a virus to infect patient with new gene

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Clones
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Possible clone use

• Cloning new stem cells to repair tissues

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Possible clone use

• Clone successful plants

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What if there isnt enough DNA in the sample?

• Tiny amounts of DNA can be amplified by a
  technique called PCR (polymerase chain reaction)

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STEP 1 PCRMaking enough DNA to read

• Three step amplification cycle
• Cycles of heating and cooling
• Causes DNA to separate (DENATURE) and then come
  back together (ANNEAL)
• Generates MORE DNA a certain size of DNA fragment
  (from one sample)

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STEP 2 CUTTING THE DNARestriction Enzyme

• We will use TA-ase, an imaginary enyzme, to cut
  our DNA
• Sample DNA strand CTGGCTAGGCTACCATGCCCGTAAAT

CTGGCTA GGCTA CCATGCCCGTA AAT
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STEP 3 SEPARATING THE DNA Gel Electrophoresis

• Electricity separates fragments by size in a gel
• Largest fragment travels least
• Smallest the most

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STEP 3 SEPARATING THE DNA Gel Electrophoresis

• CCATGCCCGTA
• CTGGCTA
• GGCTA
• AAT

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STEP 3 SEPARATING THE DNA Gel
ElectrophoresisRESULTS

• Can be used to ID persons
• Very effective means of
• Criminal identification exclusion
• Paternity cases
• Missing persons
• Entire DNA is not used, only portions known to
  differ from individual to individual
• Gel is sometimes called an autoradiograph or
  autorad

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STEP 4 READINGHow do you read a DNA
fingerprint?
Victims DNA finger print
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STEP 4 READINGHow do you read a DNA
fingerprint?
A
B
C
D
E
Victims DNA finger print
Which sample is a match?,
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STEP 4 READINGHow do you read a DNA
fingerprint?
C
Victims DNA finger print
Which sample is a match?,
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DNA FINGERPRINTTHE LAB BASICS (A SUMMARY)

• PCR to increase the amount of DNA
• Restriction enzymes to cut the DNA into
  different sized fragments
• Gel Electrophoresis to separate fragments
  according to size
• CONCLUSION Try to match fragments from
  different samples

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• I. Crime Scene DNA
• If you are the DNA analyst, you should conclude
  that
• A. Both Suspects A and B are excluded as the
  source of the evidence.
• B. Suspect A is excluded as the source of the
  evidence, but Suspect B cannot be excluded.
• C. Suspect B is excluded as the source of the
  evidence, but Suspect A cannot be excluded.
• D. Neither Suspect A or B can be excluded as a
  source of the evidence.
• E. Suspect B cannot be excluded as a source of
  the evidence. The results with Suspect A are
  inconclusive.

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Paternity Testing

• Not just matching evidence to suspect

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PATERNITY TESTING

• QUESTION
• Which child can be excluded as being the
  biological offspring of the father?
• He claims NOT to be the father of all these
  kids
• Child 1 is not his
• Child 2 is not his
• Child 3 is not his
• Child 4 is not his
• NONE of the children can be excluded they ALL
  belong to him!