Download blood types

You Inherited Your Blood Type
• Blood is the bodily substance most
commonly found at the scene of a crime or
on a person, clothing, or a weapon
potentially associated with a crime.
• The presence of antigens on cells is
genetically determined.
• Every person can inherit two A, B or O
blood type antigens – one from the mom &
the other from the dad.
You Inherited Your Blood Type
Antigens A & B
are called
Codominant.
O (absence of
both antigens)
is recessive.
Genotypes
or Antigens
AA or AO
Phenotype or
Blood Type
A
BB or BO
B
AB
AB
OO
O
You Inherited Your Blood Type
• Punnett squares are used to predict the
probable genes you inherit from your
parents.
• Biology Vocabulary review:
• Homozygous – same alleles (or antigens)
= AA or BB or OO
• Heterozygous – different alleles (or
antigens) = AO or BO or AB
You Inherited Your Blood Type
• What is the probability (or possibility) of
blood types if a mother (AA) has a child
with a father (AO)?
• Do a punnett square using dry erase
boards.
• Show genotypes and phenotypes as well
as ratios (fractions & percentages).
• A refresher is next.
You Inherited Your Blood Type
A
A
AA
A
AA
GENOTYPE
PHENOTYPE
AA – 2/4 (50%)
Type A – 4/4 (100%)
AO – 2/4 (50%)
Type B – 0/4
BB – 0/4
Type AB – 0/4
BO – 0/4
Type 0 – 0/4
AB – 0/4
O
AO
AO
AA X AO
OO – 0/4
You Inherited Your Blood Type
• Do the following crosses on the dry erase
boards provided.
• Pick a partner. Work in collaborative pairs.
• Assessment: Self & Peer Review – check
your work & your partner’s work.
• 1. BB x BO
You Inherited Your Blood Type
• Do the following crosses on the dry erase
boards provided.
• Pick a partner. Work in collaborative pairs.
• Assessment: Self & Peer Review – check
your work & your partner’s work.
• 2. AA x AB
You Inherited Your Blood Type
• Do the following crosses on the dry erase
boards provided.
• Pick a partner. Work in collaborative pairs.
• Assessment: Self & Peer Review – check
your work & your partner’s work.
• 3. AB x AB
You Inherited Your Blood Type
• Do the following crosses on the dry erase
boards provided.
• Pick a partner. Work in collaborative pairs.
• Assessment: Self & Peer Review – check
your work & your partner’s work.
• 4. AO x AO
You Inherited Your Blood Type
• In the Rh blood system, people are
classified as either Rh positive or Rh
negative.
• Rh positive have the Rh antigen.
• Rh negative do NOT have the Rh antigen.
• Rh positive can receive Rh negative blood,
but Rh negative cannot receive Rh
positive blood. This can cause serious
transfusion reactions.
You Inherited Your Blood Type
• What would be the problem if an Rh
positive father has a child with an Rh
negative mother? What might happen with
future pregnancies?
• Distributed Summarizing: Use Numbered
Heads = Choose a partner. The one with
the earliest birthday in the year is #1, the
later birthday is #2.
• Discuss the possibilities of the problem
listed above.
You Inherited Your Blood Type
• Blood typing is useful in forensics because
it shows that two samples did not have the
same origin.
• This information is called “exclusion” & is
an important aspect of criminology that
has freed many criminal suspects as well
as those who were wrongly convicted.
You Inherited Your Blood Type
• Blood typing is also used to exclude
people in paternity cases.
• Blood typing cannot prove a man IS the
father, but may be useful in showing he IS
NOT the father. DNA testing would be the
next step.
• Blood typing can give information to
narrow down a list of possible suspects.
You Inherited Your Blood Type
% of people with A, B, AB & O blood types
Type of Blood
A
% people with blood
type
41
B
10
AB
4
O
45
You Inherited Your Blood Type
% of people with Rh + & Rh - blood types
Type of Blood
Rh +
% people with this
type
85
Rh -
15
You Inherited Your Blood Type
• With this information, you can calculate
the possibility that a person would have a
particular combination of blood types.
• This was done in the O.J. Simpson Case
when experts stated “…you would have to
go to another galaxy to find a person with
the same blood type as O.J. Simpson…”
You Inherited Your Blood Type
• “Who Dunnit” Blood Typing Lab
• Lab is due before you leave at end of
period.
• Work with lab partners & table mates
• READ THE DIRECTIONS! They are
simple to follow.
• Have Fun & Learn!!!!
• Start Blood Spatter Lab Tomorrow!