blood and blood evidence
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Blood and Blood Evidence. 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 - PowerPoint PPT PresentationTRANSCRIPT
Blood and Blood Evidence
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
Composition of BloodPLASMA (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
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
Blood TypingABo
3 alleles within our populationA = Allele coding for type A surface proteinsB = Allele coding for type B surface proteinso = Allele coding for NO surface proteins
A & B alleles are codominanto is recessive to both the A and B allele
Each person inherits 1 allele from each parent to determine their ABo blood type
ABo Blood GroupsPhenotypes and Genotypes
Phenotypes
GENOTYPES???
AA or Ao BB or Bo AB ONLY oo ONLY
Sample Problems
#1If 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?#2A 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?
Blood TypingRh 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
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-?
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
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 GroupingRh+ = 85% Rh- = 15%
• US Population and MN Blood Grouping (another blood group not mentioned yet)
MM – 30%MN – 48% NN – 22%
Sample Problems
• Sample Problem #5Calculate the probability of person being Type 0 Blood and Rh- (O- Blood Type).
• Sample Problem #6Calculate the probability of a person having… AB / Rh+ / MM .