BLOOD - CSI: Coronado
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Transcript BLOOD - CSI: Coronado
Facts, Factors and Inheritance
55%
of the blood consists of plasma
45% consists of formed elements
44% of the formed elements consist of
erythrocytes
1% consists of leukocytes and platelets which is
also called the buffy coat
plasma
buffy coat
erythrocytes
The
liquid component of blood
90% of the plasma is made up
of water
8% is made up of proteins
2% is made up of several ions
Erythrocytes:
red
blood cells; function
to transport oxygen
Leukocytes: white
blood cells; function
to protect the body
Platelets: cell
fragments that
function to clot the
blood
Blood
cells, like other cells in the body, have
proteins or factors located on their surfaces
These factors can be antigens, substances
that can cause the immune system to
respond
There are 3 important blood factors used to
type a person’s blood:
The ABO System
The MNS System
The Rh Factor
In
the ABO system there are two different
blood proteins: A and B
The inheritance of these factors is based on
codominance of the A and B proteins
In codominance, both alleles (different
forms of a gene) in the heterozygote express
themselves fully
There are 3 different blood alleles:
The A and B genes are both dominant
The o gene is recessive
Based
on the 3 genes there are 4 possible
phenotypes:
Type A blood
Type B blood
Type AB blood
Type O blood
There
are 6 possible genotypes:
Possible
Genotypes
AA
Ao
BB
Bo
Blood
Types
Type A
Type A
Type B
Type B
AB
oo
Type AB Type O
The
inheritance of the ABO system can be
predicted using Punnett squares
EX: A woman who is heterozygous for Type A
blood has a child with a man who is
heterozygous for Type B blood. What are the
possible genotypes and phenotypes of their
child?
A
o
B
AB
Bo
o
Ao
oo
Genotypes: AB, Bo, Ao, oo
Phenotypes: Type AB, Type B,
Type A, Type O
This
system is important not only in forensics
but in the medical field
It is important for blood transfusions
It is essential that the ABO blood types match
to prevent the blood from clumping
Type
A Blood:
Has A antigens and anti-B antibodies
If this person receives type B or type AB
blood, the blood will clump as the anti-B
antibodies attack the B antigens
Can receive type A and type O blood
Makes up 40% of the population
Type
B Blood:
Has B antigens and anti-A antibodies
If this person receives type A or type AB blood, the
blood will clump
Can receive type B and type O blood
Makes up 11% of the population
Type
AB Blood:
Has A and B antigens and no ABO antibodies
Because this person doesn’t have ABO antibodies,
they can receive any type blood, making this
person the universal recipient
Makes up 4% of the population
Type
O Blood:
Has no antigens and anti-A and anti-B antibodies
Because this person doesn’t have antigens, they
can donate to any type blood, making this person
the universal donor
Can only receive type O blood
Makes up 45% of the population
Similar
to the ABO System
A person carries either the M protein, the N
protein or the S protein on their blood cells
M is found in 30% of the population
N is found in 22% of the population
S is found in 48% of the population
The
Rh protein can be found on the surface
of the blood cell
Rh+: the person has the Rh antigen; it is
found in 84% of the population
Rh-: the person does not have the Rh
antigen; makes up 16% of the population
O+ 38 percent of population
A+ 34 percent of population
B+ 9 percent of population
AB+ 3 percent of population
O- 7 percent of population
A- 6 percent of population
B- 2 percent of population
AB- 1 percent of population
Knowing
the percentages of the population
with the different blood factors can be used
to determine the likelihood of a certain
combination of blood factors
By multiplying the ratios of the types, you
can determine the probability of having a
certain blood type
EX:
What is the probability of a person
having blood type A and N and being Rh-?
A
N
Rh40% x 22% x
16% = ?
.40 x .22 x .16 = .01
1 out of every 100 people would have blood
type A and N and be Rh-