Transcript Blood Type - Net Start Class

Who’s My Daddy?
Name:
DOB:
Breed:
Loki
~Aug. 2004
Unknown
Loki could be a cross between
two or even three dogs….
Can you guess who his daddy
might be?
Shetland sheepdog? Eskimo spitz?
Welsh Corgi?
Ch. 13, Genetic
Engineering
Section 13.1
• Selective breeding – taking advantage of
naturally occurring genetic variations in
Box 1
organisms and passing those traits on to the
next generation
Canis lupus
Gray wolf
Papillion
Poodle
Shetland Sheepdog
Pug
Golden Retriever
Selective Breeding and Hybridization
• Hybridization- crossing dissimilar individuals to
Box 2
bring out the best in both organisms
X
+
Dancing Slippers
Little Rascal
Best of Breed – Siamese CatBest of Breed –
American shorthair
Mommy?
Daddy?
=
=
Kuki
Snowshoe Siamese
Selective BreedingInbreeding
• Inbreeding – continued breeding of Box 3
individuals with similar characteristics,
preserves wanted characteristics
– Good: maintains certain characteristics, it’s
how we got all those different dog breeds Box 3
– Bad: most members are genetically similar,
meaning recessive traits can be expressed,
and they are less resistant to diseases
Does this rule
apply to cats?
Or are only
dogs dumb
enough to be
inbred?
Increasing Variation
• Inducing (causing) mutations can create Box 4
genetic variation
• Today we can manipulate and modify
the genetic code of many organisms
– Genetic engineering
– Extract DNA, cut with enzymes, separate
with gel electrophoresis,
– Make copies of DNA using the
Polymerase Chain Reaction (PCR)
– Use cell transformation to see how a
modified gene works
I’ve mutated!
Restriction Enzymes
Box 5
Recognition sequences
Restriction enzymes cut DNA
at a restricted point, a certain
base sequences called
recognition sequences
DNA
sequence
Sticky end
Restriction
enzyme EcoRI
cuts the DNA
into
fragments.
Chop! Chop!
Gel Electrophoresis
Power source
Shorter
fragments
DNA plus
restriction
enzyme
Gel
Longer
fragments
Box 5
Why would we do all this?
Mixture of DNA fragments
To be able to examine and compare DNA and genomes of different
organisms, and to try to discover the functions of different genes
and gene combinations.
Forensics uses these techniques to locate and compare one gene
out of thousands in a person’s genome.
Transgenic Organisms
• Genetic engineering uses
biotechnology to study how genes work
and help organisms live
Box 6
• Transgenic means one organism
contains genes from another organism
– Transgenic Mice – used used to express
human genes and allows us to study the
effect of gene modifications
– Transgenic Plants - genetically modified
plants are an important part of our food
supply
Cloning
Box 7
• Clone = a member of a population of
genetically identical cells produced from a
single cell
Box 8
• In 1997, Ian Wilmut announced he had
cloned a sheep named “Dolly”
– Since then, researchers claim to have cloned
many different animals, but no humans or
monkeys
Dolly and her mother
• Cloning holds the promise for curing and
treating many human diseases, but to date,
it’s very controversial and even illegal in the
US
Box 9
Cloning Dolly
Step 1: A donor cell is
taken from a sheep’s
udder.
Step 2: An egg
cell is taken from
an adult female
sheep.
Donor
Nucleu
s
Box 10
Step 4: These two cells are
fused using an electric
shock.
Fused
Cell
Egg
Cell
Step 3: The nucleus
of the egg cell is
removed.
Cloned Lamb
Step 7: The embryo
develops normally
into a lamb—Dolly
Foster
Mother
Step 6 : The
embryo is placed
in the uterus of a
foster mother.
Step 5: The fused cell
begins dividing normally.
Embry
o
Cloning
A body cell is taken from a donor animal.
An egg cell is taken from a donor animal.
The nucleus is removed from the egg.
The body cell and egg are fused by electric shock.
The fused cell begins dividing, becoming an
embryo.
The embryo is implanted into the uterus of a foster
mother.
The embryo develops into a cloned animal.
Cloning Gone Bad….
Pug + Chimpanzee
Persian cat + lion?
Cat-ion?
Li-cat?
Goat
Sheppard?
Pug-azee? Chimpapug? Goat + German
Sheppard
Penguin + monkey + cat
Orangutan + dog
Orangudog?
Dogutan?
Great Dane + Horse
Gorse? Horsedane?
Dachshund + Owl
Dowl?
Owllund?
Ch. 14, Human Heredity
• Humans have 46 chromosomes in every cell of
our bodies, except where?
• Gametes = eggs and sperm (23)
• We look at our 46 xsomes using a Karyotype
• We trace inheritance patterns using a Family
Pedigree
• We predict traits in offspring using Punnett
Squares
Pedigree
Karyotype of a Human
Box 11
Sex Chromosomes
• We have 23 pairs of chromosomes, but 2 pairs
are called sex chromosomes (X and Y)
– determine a person’s sex (male or female)
– Males = one X and one Y (XY)
Box 12
– Female = two X’s (XX)
• Autosomes = the other 22 pairs of
chromosomes, everything but the sex
Box 13
chromosomes
• Therefore we write the genotypes as:
– Males = 46, XY
– Females = 46, XX
Punnett Square with Sex
Chromosomes
Fill in your Punnett square
As always, it
doesn’t matter
which genotype
you put on the top
or the side, this
could be switched
and you would still
get the same
result.
Box 14
X
Y
X
XX
XY
X
XX
XY
Ratio of male to female?50:50 or 1:1
In a population, ~ ½ of the zygotes
(embryos) are male, and ½ are female
Box 14
Human Traits
• Human traits are inherited according to the same
principles discovered by Gregor Mendel
Box 15
– To apply Mendelian genetics, first we must establish that
ONE trait is controlled by a single gene
• To identify this inherited trait, we construct a
pedigree
Pedigree of a Dominant Trait
Pedigree of a Recessive Trait
Did you miss me? I
missed you!
How to Read a Pedigree
Box 16
A circle represents a
female.
A square represents a male.
A horizontal line
connecting a male
and female
represents a
marriage.
A vertical line
and a bracket
connect the
parents to
their children.
A half-shaded circle
or square indicates
that a person is a
carrier of the trait.
A completely
shaded circle or
square indicates
that a person
expresses the trait.
A line through
a circle or
square means
the person is
dead
A circle or
square that is
not shaded
indicates that a
person neither
expresses nor
is a carrier of
the trait.
How to Use a Pedigree
marriage
female
Affected person
male
childre
n
death
Carrier of trait
(heterozygous)
Genetic counselors analyze
pedigrees, trying to identify
Unaffected person
inheritance patters (dominant,
recessive, sex-linked)
1. Define the problem: What problem
are you trying to solve?
Box 17
2. Organize the information: Create a pedigree, label each
person, identify affected and unaffected (phenotype)
3. Create a solution: Analyze the pattern of inheritance and
use the information to explain how the trait is inherited
Genes and Environment
Note: Genetics only partly determines yourBox 18
physical traits. Your environment also effects
and can influence the expression of traits.
Box 19
• Many traits are polygenic (a trait controlled by
many genes)
• Examples of polygenic traits are:
– Height, Skin color, Weight
Examples of effects of environment:
Height and weight are influenced by
diet and nutrition, weight is strongly
influenced by exercise, and skin color
can depend on amount of sun
exposure.
Genes + Environment = Phenotype
Human Genes
• By 2000, we had complete sequence of the
human genome (Human Genome Project), but
identifying a single gene out of 1000’s is still
very difficult
• One of the 1st genes to be discovered were the genes
controlling blood groups (ABO)
• Why is it important to know your blood type?
Box 20
• Blood transfusions, organ replacementgetting the wrong blood type could kill you!
• Rh+/- blood group- + is dominant
(Rh stands for “rhesus monkey,”
where this gene was 1st identified)
– An antigen in our immune system,
helps recognize foreign invades like
someone else’s blood!
Blood!
Gimmie
blood!
Blood Type Groups
Box 21
• 3 alleles for blood type in ABO blood I = Immunoglobulin
Antibodies or proteins
A
B
i
=
represents
the
group I I i
found in blood and
Blood type A = IAIA, or IAi
Blood type B = IBIB, or IBi
Blood type AB= IAIB
Blood type O = ii
O allele, which is
recessive
Box 21
tissue fluids produced
by cells of the immune
system. They bind to
substances in the body
that are recognized as
foreign antigens.
• Conventionally, we write blood types with the IA or IB but if you just
remember what the I stands for,you can write it in a much simpler
way
Try this instead….
Blood type A = AA or AO
Blood type B = BB or BO
Blood type AB = AB
Blood type O = OO
Human Blood Types
Blood Type A = IA IA or IA i Box 22
(easier way= AA, or AO)
produces the A antigen on the
surface of a red blood cell
IA IA or IA i
AA or AO
Antigen A
Blood Type B = IB IB or IB iBox 23
(easier way= BB, or BO)
produces the B antigen on the
surface of a red blood cell
IB IB or
IB i
BB or BO
Antigen B
A blood is evil
B blood is
the enemy!
Red Blood
Cell
Anti-B antibodies
and must be
destroyed!
Red Blood
Cell
Anti-A antibodies
Can donate blood to A and AB
Can donate blood to B and AB
Can receive blood from A, O
Can receive blood from B, O
Human Blood Types Cont.
Blood Type AB = IA IB (easier way = AB)
produces both the A and B antigen on the
surface of a red blood cell
Box 24
IA IB
AB
Antigen B
Blood Type O = ii (easier way = OO)
produces NO antigens the surface of a
red blood cell
Box 25
OO
I love all blood!
Can’t we all just
get along?
ii
I am so
generous! Iii
donate to
everyone.
Antigen A
Red Blood
Cell
No Anti antibodies
Red Blood
Cell
I have no
antigens to
protect me! I’m
exposed!
Helpless!
Somebody save
me!
Anti-A and Anti-B antibodies
Can donate blood to AB only
Can donate blood to A, B, O, and AB
Can receive blood from A, B, O, and AB
Universal Donor!!!!
Universal Receiver!!!!
Can receive blood from O only.
Blood Types Summary
Phenotype
(Blood Type)
Genotype
Antigen on
Red Blood Cell
Safe
From
ToTransfusions
Blood Type Frequencies in the US:
O+ = 38%
O- = 7%
A+ = 34%
A- = 6%
45%
B+ = 9%
B- = 2%
11%
40%
AB+ = 3%
AB- = 1%
4%
Recessive Alleles
Box 26
• To expressive a recessive trait, you must
have 2 copies of a recessive allele (bb, tt,
ss, etc.)
• Look at Figure 14-6 in your book
• An example of an Autosomal recessive
Warning on a can of Coke
disorder: Phenylketonuria (PKU) or Pepsi:
“Phenylketonurics:
– Recessive disorder
Contains phenylalanine”
– Missing enzyme needed to break down Box 27
phenylalanine
– In babies, phenylalanine builds up in the
child’s tissues and causes severe mental
retardation
– Babies are tested for PKU at birth, and there is
Dominant Alleles
There is a genetic test for Huntington’s,
would you want to be tested if the disease
ran in YOUR family?
• You only need one dominant allele to express
the dominant trait (Tt, Bb, Cc, Ss, etc.)
• 2 examples of Autosomal dominant disorders
are:
• Achondroplasia (ay-kahn-droh-PLAY-zhuh) Box 28
– Dwarfism, where person never grows above 4’4”
• Huntington's Disease
– Affects the nervous system
– Progressive loss of muscle control and mental
function, eventually causes death
– Late onset, ~30’s or older, why is this bad?
• By then people with Huntington’s could
have already had kids, and passed the
dominant gene to the next generation
Box 29
normal rbc
Codominant Alleles
•
•
Box 30
Codominance means both alleles are expressed equally
Sickle Cell Disease is caused by a Codominant allele
– Affects 1 out of 500 African Americans
– Sickle cell disease is characterized by the bent
sickle cell rbc
and twisted shape of the red blood cells (rbc)
Box 31
(they look like sickles)
– Deformed rbcs tend to stick in the capillaries
(narrowest blood vessels) and stop movement
of blood, damaging tissues and organs
Box 31
– This disease is sometimes fatal, and is very painful
– Hemoglobin is a protein in rbcs that carries O2, and 1
change in the Hemoglobin gene causes sickle cell disease
– Why do so many African Americans carry this sickle cell
allele?
• People heterozygous for this allele have a higher
Box 31
protection against Malaria, a disease prevalent in West
Africa
Cystic Fibrosis (CF)
• Cycstic Fibrosis (CF) is caused by a
single mutation in the CF gene
• CF is the most common genetic
disease in Caucasians
Box 32
– Children with CF have digestive problems
– Excess of mucus in their lungs causes
breathing problems
• CF is caused when 3 base pairs of DNA
Box 32
are deleted
– What would happen to the protein if 3
bases were deleted from the DNA
sequence?
Box 32
=Loss of an amino acid (3 bases = a codon)
Human Chromosomes
Box 33
• Each cell in your body (except gametes!)
contains approximately 6 billion base pairs of
DNA
• All the DNA is tightly packed into our 46
chromosomes
• Average gene length is
3000 base pairs
• 1000’s of genes onWhich
each
chromosome
What
happens if
chromosome is the
one chromosome
is missing?
largest?
Which chromosome
is the smallest?
1000’s of genes are
missing, and this
usually results in
disease and death
Box 32
Is this person male
or female?
Male = has X and Y
Human Karyotype
Are you colorblind?
Test #1
What do you see?
Everyone should see #16
Test #2
What do you see?
Color normal sees #2
Colorblind sees nothing
Test #3
What do you see?
Color normal sees a square
and a faint brown circle
Colorblind sees a square only
What do you see?
Color normal sees a faint sailboat
Colorblind sees nothing
Sex Linked Genes
Box 34
• Genes located on chromosomes X and Y are
called Sex Linked genes
• Many sex linked genes are found on the X and
very few are found on the Y (much smaller!)
• Colorblindness- 2 of the 3 human genes for
color vision are located on the X, and males
with a defective version of any 1 of these
genes will have colorblindness
• Why? Males = XY, only one copy of X, whatever is on that X is
Box 36
Box 35
expressed
Colorblind male =
XcY
Colorblind female = XcXc
Normal male = XCY
Normal carrier female = XCXc
Normal female = XCXC
Colorblindness and the Punnett Square
Box 37
Father
(normal vision)
Colorblind
Normal
vision
Male
Female
Daughter
(normal vision)
Son
(normal vision)
Mother
(carrier)
Daughter
(carrier)
Son
(colorblind)
Chances of these parents having a colorblind son? 1:2 or 50%
Chances of these parents having normal sons?
1:2 or 50%
Chances of these parents having normal kids?
3:4 or 75%
Box 37
Other Sex Linked
Disorders
• Hemophilia- 2 genes on the X help control
blood clotting, a recessive defective allele in
either of these genes produces Hemophilia
Box 38
• People with hemophilia are missing a protein
necessary for normal blood clotting
• About 1 in 10,000 males is born with a form of
hemophilia
• Can bleed to death, may need multiple blood
transfusions
• Duchenne Muscular Dystrophy- progressiveBox 39
muscle wasting disorder
– One out of every 3000 males in the US is born
with this condition
– Caused by a recessive defect in a muscle protein
gene
X Inactivation
• Females have 2 X chromosomes, but males have
only 1 X, why is having1 X enough for males?
Box 40
• In women, one of the X’s is randomly inactivated,
this is called = Lyonization
(named after Mary Lyon, the scientist who discovered this
effect)
•In cats, the gene for coat color is found
on the X chromosome.
•In some parts of the body, one X is
activated, and the other X is inactivated
in other parts of the body, resulting in
the calico coloration.
•One X may have an allele for orange
spots, the other X an allele for black
spots.
Box 41
Male cats can only have spots of 2 colors, while females can have spots of 3 colors.
Chromosomal Disorders
• Chromosomes separate during Meiosis, but
Box 42
sometimes something goes wrong, oh no!
• Most common error = Nondisjunction = when
homologous chromosomes fail to separate
WARNING:
System
overload!
Warning! Nondisjunction is
occurring! = Homologous
chromosomes are failing to
separate
Missing a
copy of one
chromosom
e
WARNING:
Sisters! You
have failed to
separate!
2 copies of
one
chromosom
e
Meiosis I:
Nondisjunction
Meiosis
II
If nondisjunction occurs, abnormal #’s of chromosomes may appear in
gametes, and a chromosomal disorder usually results.
Box 43
Down’s Syndrome
• If nondisjunction occurs, 2 copies of an
autosomal chromosome failed to separate
during meiosis, and the individual has 3 Box 44
copies of a single chromosome = Trisomy
• Trisomy (tri = 3) –somy
(of chromosomes)
• Down’s syndrome is the most
common form of trisomy, it’s called
Trisomy 21
– 3 copies of chromosome 21
– Down’s Syndrome = mild to severe
retardation, increased susceptibility to many
diseases, higher incidence of heart defects and
a higher frequency of birth defects
Box 45
Sex Chromosome Disorders
• Nondisjunction in Meiosis I can cause
many diseases, such as…
• Turner’s Syndrome & Klinefelter’s
Syndrome
– Turner’s syndrome – when a female inherits
Box 46
only one X instead of 2 X’s
– Her karyotype would be 45, X
• She is sterile, and sex organs do not develop at
puberty
Box 46
– Klinefelter's syndrome – when a male inherits
an extra X
– His karyotype would be 47, XXY
• Sterile, can not reproduce
• Normal development
of male sex region
organsthat’s necessary to product
The Y chromosome
contains a sex-determining
male sex organs, even if there are extra X’s present. Men with Klinefelter’s syndrome
do have normal male organs, but the extra X interferes with normal meiosis (production
Human Molecular Genetics
• Human DNA analysis, testing for disorders?
Should we do this? Can we do this?
• Tay-Sachs testing
• Huntington's testing
• Would insurance companies cover you if they knew you
were going to be sick or have sick children?
• DNA Fingerprinting- identifying a person based on
Box 47
their own unique DNA fingerprint
• DNA Forensics- uses material left at a crime scene to
determine guilt or innocence of a suspect
• Human Genome Project- ongoing effort to
analyze the human DNA sequence
• Rapid sequencing using “shotgun sequencing
• Searching for genes, finding out what the genes we do find
do
• Making the data public, accessible to everyone
Human Molecular Genetics
• Gene Therapy- an absent or faulty gene is Box 48
replaced by a normal, working gene
– Information from the Human Genome Project will be
useful for this kind of treatment
– Use modified viruses as “vectors” to get into a
patient’s cells carrying “fixed” DNA, replacing the
faulty gene
• Ethical Issues- manipulating our own DNA, or
that of another organism, leads to questions
about ethical issues like….
Box 49
– Where do we set limits on what we change and don’t
change?
– Who gets the treatment? Who does not?
– What are the goals of biology and research?
– Is manipulating our genome or the the genome of
other organisms ethical? Moral?