Download bloodtype ppt - Peoria Public Schools

Blood Typing and Blood
Genetics
Blood Genetics
The human ABO gene is on chromosome 9.
 Everyone has two copies of chromosome 9
so you have two ABO genes.
 One copy is inherited from our mother, the
other from our father.

Alleles

There are three versions (called “alleles”) of
this blood type gene: A, B, and O.

A person’s blood type is determined by
which allele he/she inherits from each
parent.
Pheno vs. Geno
The genetic makeup of an organism is
called the “genotype”.
 The “phenotype” is the visible properties of
an organism.
 In this case, the A, B, and O allele
combination a person has is their genotype
 Their blood type is their phenotype.

Dominant vs. Recessive Genes
The “A” allele is dominant and so is the “B”
allele.
 Together though, the “A” and “B” alleles are
co-dominant.
 The “O” allele is recessive.

Determining the Genotype
The blood type gene has three different
alleles:
 IAIA is Type A
 IAIB is Type AB
 IBIB results in Type B
 ii is Type O
Determining the Genotype

Scenario:
Mom has the alleles IAIA for blood type and Dad
has the alleles IBIB blood type.
 What will be the blood type for their child?

Punnett Sqaures
IA
IB
IB
IA
Practice
Suppose that a mother has blood Type A
and genotype IAi and the father has blood
Type B and genotype IBi. Draw a Punnett
square to show the possible genotypes of
their children.
What are the phenotypes of the kids?
Practice
B
I
A
I
i
i
Blood Types
The alleles we discussed “code” for blood
type.
 What they REALLY “code” for is a specific
enzyme.
 That enzyme creates specific antigens on
your RBC.

Antigens
An antigen is a protein (encoded from the
right enzyme) that “sits” on the surface of
your RBC.
 There are 2 different blood antigens, A and
B.
 If you have the A antigen, you have type A
blood.
 If you have the B antigen, you have type B
blood.

Antigens of the Surface of the RBC
Antibodies
Blood plasma is packed with proteins called
antibodies.
 The body produces a wide variety of
antibodies that will recognize and attack
foreign molecules.
 A person’s plasma does not contain any
antibodies that will bind to molecules that
are part of his or her own body.

Blood Transfusions
Tt is important to carefully match the donor
and recipient blood types.
 If the donor’s blood cells have antigen that
are different from those of the recipient,
antibodies in the recipient’s blood recognize
the donor blood as foreign.
 This triggers an immune response resulting
in blood clotting.

Blood Transfusions
Antigen
A
B
AB
O
Antibody
Can donate Can receive
to…
from…
Relative Abundance of Blood Types
A
B
40-42% 10-12%
AB
O
3-5%
43-45%
Interesting Facts
Men generally have more red blood cells
than women.
 Rare blood types exist in addition to the
basic ABO system.

Rhesus Factor (Rh)
If a person has a positive Rh factor, this
means that their blood contains a protein
that is also found in Rhesus monkeys.
 Most people (about 85%) have a positive Rh
factor
 Rh is expressed as either positive or
negative.
 The Rh factor, like other antigens, is found
on the surface of the red blood cells.

Stats
O+
OA+
AB+
BAB+
AB-
1 in 3 persons
1 in 15 persons
1 in 3 persons
1 in 16 persons
1 in 12 persons
1 in 67 persons
1 in 29 persons
1 in 167 persons
Can Blood Be Individualized?
Is based on the typing of proteins and
enzymes. Blood proteins have subtypes.
 Most people are familiar with at least one
common polymorphism in blood: Hb, which
causes sickle-cell anemia.
 You can also extract DNA from it.

Bloodletting is
one of the oldest
medical practices,
having been
practiced among
ancient peoples
including the
Egyptians and the
Greeks.
Bloodletting 15th Century
Text book of Bloodletting
The barber poles that we
may still see today are a
result of these ancient
blood letting practices.
By the middle ages, both surgeons
and barbers were specializing in
this bloody practice. Barbers
advertised their blood letting
practices with a red (for blood) and
white (for tourniquet) striped pole.
The pole itself represented the
stick squeezed by the patient to
dilate the veins.
By the end of the 19th century
(1875-1900), phlebotomy was
declared quackery.
http://www.pb
s.org/wnet/red
gold/basics/ba
rbersurgeons.
html
Did blood letting lead to the final demise
of our 1st president?
On December 14, 1799, George
Washington contracted an illness that
inflamed his throat. His health
deteriorated rapidly.
Doctors tried to treat him by bloodletting,
a common medical procedure during this
time period for most types of ailments.
After being drained of 3.75 liters of blood
within 24 hours, his illness and the
bloodletting weakened him, and he died
later that same day. (Adults have 5.6 liters
of blood)
Leeches and Bloodletting
Most people today regard leeches as disgusting,
but for centuries these blood-sucking creatures
were a mainstay of medical care. Derived from
the Anglo-Saxon word loece, to heal (Medieval
doctors called themselves leeches).
The leech was used as an adjunct to bloodletting,
in places too sensitive or confined for the lancet
or other blood-letting instruments. Physicians
applied leeches to areas such as "the gums, lips,
nose,and fingers“.
Leeches became popular in the 19th century -- so
much so that the species became endangered in
Europe. In 1833 alone, French doctors imported
41,500,000 leeches. Eventually the procedure
was largely abandoned, along with other forms of
bloodletting.
The leech was
indispensable in 19th
Century medicine for
bloodletting, a practice
believed to be a cure for
anything from headache
to gout. As the use of
leeches increased many
pharmacists became
responsible for their
care and dispensation.
Today leeches have found renewed
utility in certain surgical procedures,
particularly after microsurgery. Doctors
sometimes find it helpful, for example,
to use leeches to restore circulation to
a re-attached finger or other small
body parts, or to portions of the skin
following plastic surgery.
Leeches Used in Medicine
Successful
reattachment of
severed ear, as
blood continued to
flow and carry
nutrients to the
damaged region