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