Download 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-