1. Blood and Blood Evidence

2. SEROLOGY Serology- the study of blood – 1901- Karl Landsteiner discovers ABo blood groups. 29 years later was awarded Nobel Prize for this feat. – 1937- Rh factor was identified – Up until early 1990’s many other blood factors were being studied in an attempt to individualize blood evidence class vs individual evidence

3. Composition of Blood PLASMA (55%)- fluid portion of blood * similar to salt water -mainly water -dissolved salts, nutrients, proteins, antibodies, hormones ect… SUSPENDED MATERIALS (45%)- “free floating” materials/cells *Red blood cells = ERYTHROCYTES -carry oxygen *White blood cells = LEUKOCYTES -fight disease and foreign invaders *platelets = THROMBOCYTES -blood clotting and repair of damaged blood vessels Composition of Blood

4. KEY TERM Antigens- substances, usually proteins, that can be found on the surface of our cells. – Creates ABo blood group – Creates Rh+/Rh- blood group – Many other blood groups have been identified as well

5. Blood Typing ABo 3 alleles within our population A = Allele coding for type A surface proteins B = Allele coding for type B surface proteins o = Allele coding for NO surface proteins A & B alleles are codominant o is recessive to both the A and B allele Each person inherits 1 allele from each parent to determine their ABo blood type

6. ABo Blood Groups Phenotypes and Genotypes Phenotypes GENOTYPES??? AA or AoBB or BoAB ONLY oo ONLY

7. Sample Problems #1 If a woman who is heterozygous with type A blood (Ao) marries a man with type O blood, what is the probability that their children will have type A blood? B blood? AB blood? O blood? #2 A woman who is homozygous with type B blood (BB) has a child out of wedlock that has type O blood. She files a paternity suit against a man with type O blood. Is the lawsuit valid?

8. Blood Typing Rh Factor Rh factor is another type of surface protein which may be produced on the surface of our cells. Rh+ (producing Rh protein) is dominant over being Rh- (not producing Rh protein) R = allele for production of Rh protein (Rh+) r = allele for NO Rh protein (Rh-) Each person inherits 1 allele from each parent GENOTYPES AND PHENOTYPES RR = Rh+ blood Rr = Rh+ blood rr = Rh- blood

9. Sample Problems #3 A man who is Rh- marries a woman who is heterozygous with Rh+ blood. What is the probability that their children will be Rh+? Rh-? #4 A woman who is homozygous with Rh+ blood marries a man who is heterozygous with Rh+ blood. Is it possible for them to have a child who is Rh-?

10. Using Blood Typing as Class Evidence Identifies the presence or absence of particular proteins embedded in the cell Quicker and less expensive than DNA profiling Produces class evidence but can still link a suspect to a crime scene or exclude a suspect

11. US Population and Blood Groups US Population & ABo Blood Grouping Type A Blood – 42%Type AB Blood – 3% Type B Blood – 12%Type O Blood – 43% US Population and Rh Blood Grouping Rh+ = 85% Rh- = 15% US Population and MN Blood Grouping (another blood group not mentioned yet) MM – 30%MN – 48%NN – 22%

12. Sample Problems Sample Problem #5 Calculate the probability of person being Type 0 Blood and Rh- (O- Blood Type). Sample Problem #6 Calculate the probability of a person having… AB / Rh+ / MM.