Post on 05-Jan-2016
Figure 16.0 Watson and Crick
Figure 16.3 The structure of a DNA stand
Figure 16.6 Base pairing in DNA
Figure 16.5 The double helix
Activity• You and a partner will build a piece of DNA
that is 6 base pairs long on each side
• One bag will contain all of the materials that you need
• Black is sugar, red is phosphate group and yellow represents the bond between them
• Create a key so that I know what each color represents
• Use p. 355 in your textbook to help
Figure 16.8 Three alternative models of DNA replication
Figure 16.7 A model for DNA replication: the basic concept (Layer 1)
Figure 16.7 A model for DNA replication: the basic concept (Layer 2)
Figure 16.7 A model for DNA replication: the basic concept (Layer 3)
Figure 16.7 A model for DNA replication: the basic concept (Layer 4)
Figure 16.10 Origins of replication in eukaryotes
Figure 16.12 The two strands of DNA are antiparallel
Figure 16.13 Synthesis of leading and lagging strands during DNA replication
Figure 16.14 Priming DNA synthesis with RNA
Figure 16.16 A summary of DNA replication
Figure 20.7 The polymerase chain reaction (PCR)
Figure 20.8 Gel electrophoresis of macromolecules
Figure 20.9 Using restriction fragment patterns to distinguish DNA from different alleles
Figure 20.17 DNA fingerprints from a murder case
This is electrophoresis for ALL DNA. Don’t use anymore
Switched to RFLP Analysis because one locus
• Enzymes break DNA into restriction fragments
• Measurements taken of fragments that vary in length across people (length polymorphism) because they contain VNTRs
• can produce extremely low random match probabilities
• requires relatively large fresh samples (>50 ng DNA)
• slow and expensive
Which Suspect, A or B, cannot be excluded from
the class of potential
perpetrators of this assault?
Figure 20.12 Sequencing of DNA by the Sanger method (Layer 1)
.Figure 20.12 Sequencing of DNA by the Sanger method (Layer 3)
Figure 20.12 Sequencing of DNA by the Sanger method (Layer 4)
Problems
• Sperm is very durable and long lasting
• Sperm on clothing can be washed and transferred to other clothing in wash
• So may be used to show someone had sex with another when they may not have
Human Identity Testing• Forensic cases -- matching suspect with evidence
• Paternity testing -- identifying father
• Historical investigations-Czar Nicholas, Jesse James
• Missing persons investigations
• Mass disasters -- putting pieces back together
• Military DNA “dog tag”
• Convicted felon DNA databases
• Mitochondrial DNA from mother to sons and daughter
• Male transfers his Y chromosome DNA to just his son
Short Tandem Repeats (STRs)
3. Capillary Electrophoresis
AmpFlstr Profiler Plus
• Groups of amplified STR products are labeled with different colored dyes (blue, green, yellow)
• Electrophoresis and detection occur in computer-controlled capillary device (ABI Prism 310 Genetic Analyzer)
Across is size, up and down is number or repeats at that spot
Next 2 slides go together
15,1616,1720,23 12,14 30,30X,Y 13.2,15Evidence
Area 1 Area 2Area 3 Area 4 Area 5
AREAS OF DNA
SAMPLE Sex Area 6
Ref.Std.2
Ref.Std.1
15,1616,1720,23 12,14 30,30X,Y 13.2,15
14,1517,1823,24 13,13 30,30X,X 15,1914,1517,1823,24 13,13 30,30X,X 15,19