Warm Up
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Table of Contents
March 19th
7.L.2.2
Pedigree
Notes
March 19th
7.L.2.2 Pedigree
How do Pedigrees help determine inheritance of
genetic traits and diseases?
Pedigrees
What is a pedigree?
-Pedigrees are family trees which show
which individuals in the family get certain
diseases or have certain traits.
Why are pedigrees important?
Scientists use pedigrees to track/trace the
passing on of genes and traits over
generations.
Pedigrees help determine how genetic
diseases are passed through families
Pedigrees show generations – kind of like a
family tree
Pedigrees show generations
Each row represents a generation
Generation 1
Generation 2
Generation 3
Pedigrees show gender
Shape
Gender
circle
Female
square
Male
Pedigrees Show Marriage/ Mating
A horizontal line connecting a circle
and a square means the male and
female are “married”
Pedigrees show children
Vertical Line connect parents and
children
Parents
Children
Pedigrees shown Genotypes /
Affectedness
shaded / colored = has trait
a colored in shape always has the
recessive trait
unless otherwise stated
Two lower cases in genotype
half shaded = carrier / heterozygous
Clear shape = homozygous dominant
genotype
Heterozygous if child is colored in
Genotype written as E? (letter and ?)
Shaded = homozygous recessive
Half = heterozygous
Clear = Homozygous Dominant or
Heterozygous (depends on child’s
genotype)
Pedigrees show Death
Circle or Square with diagonal line means
person has died
http://www.youtube.com/watch?v=Wuk0W10
EveU
Rules of Logic for Reading A
Pedigree
1. If neither parent show the trait:
• a. the trait cannot be dominant.
• b. the trait could be recessive and either parent or both could be
heterozygous carriers.
2. If one parent shows the trait:
• a. the trait could be dominant and the affected parent could be
heterozygous while the unaffected parent is not a carrier
• b. the trait could be recessive and the affected parent is homozygous while
the unaffected parent could be a heterozygous carrier
3. If both parents show the trait:
• a. the trait could be dominant and both parents could be heterozygous
carriers which
• means that some of the children could be unaffected
• b. the trait could be recessive meaning that both parents would have to be
homozygous and
• all the children would have to be affected
Pedigree 1 shows a family of parrots. One of the offspring shows the
trait for blue feathers. (R = red feathers, r = blue feathers)
1.
Do you think blue feathers are dominant or recessive?
recessive
2. What must the genotypes of the parents be?
Rr
3. What two genotypes could the other offspring have?
RR or Rr
1. Father has green leaves
2. Male = gg, female = Gg
1. Bb
2. bb
3. Bb or BB
Reading a Pedigree
1. How many males are there?
2. How many females are there?
3. How many children did the first
generation parents have?
4. How many sets of married couples
Does the pedigree show?
5. How many carriers does the pedigree show?
6. How many affected individuals does the pedigree show?
1. How many males are there?
4
2. How many females are there? 5
3. How many children did the first
generation parents have? 3
4. How many sets of married couples
Does the pedigree show?
3
5. How many carriers does the pedigree show? 0
5. How many affected individuals does the
pedigree show? 1
Practice
1. Genetics Pedigree Worksheet
#1 > no dimples = dd (colored in = no
dimples)
#2 > unibrow = ee (colored in = unibrow)
#3 > colored in = dd
Warm Up
• Put Pedigree HW worksheet on desk
• Answer front side of handout (the side that says
Warm Up)
READ KEY AT THE BOTTOM OF THE PAPER
Colored = Free
Blank = Attached
F = Dominant, Free
f = Recessive, Attached
Review Exit Ticket
How many generations?
3
The chart shows a total of 5
female offspring. How
many of these women are
carriers of colorblindness?
2
Of the 3 male offspring, how
many have colorblindness?
2
Notes
Table of Contents
March 20th
Pedigree Day 2
Notes
March 20th
Pedigree Day 2
How do you interpret a pedigree chart?
Identifying People in Pedigrees
Roman Number of Generation and then
Number in row
IV 1
II 7
Review HW
a. How many males are there? 8
b. How many males have hemophilia? 3
2. A circle represents a female. If it is darkened, she has hemophilia; if open
she is normal.
a. How many female are there? 8
b. How many females have hemophilia? 2
3. A marriage is indicated by a horizontal line connecting a circle to a square.
a. How many marriages are there? 3
4. A line perpendicular to a marriage line indicates the offspring. If the line ends
with either a circle or a square, the couple had only one child. However, if
the line is connected to another horizontal line, then several children were
produced, each indicated by a short vertical line connected to the horizontal
line. The first child born appears to the left and the last born to the right.
a. How many children did the first couple (couple in row I) have? 2
b. How many children did the third couple (couple in row III) have? 7
5. Level I represent the first generation, level II represents the second
generation.
a. How many generations are there? 4
b. How many members are there in the fourth generation? 7
I
II
III
6. Write the generation on the pedigree numbers (roman
numerals).
7. Which members of the family above are afflicted with
Huntington’s Disease? I-1, II-2, II-3, II-7, III-3
8. There are no carriers for Huntington’s Disease- you
either have it or you don’t.
With this in mind, is Huntington’s disease caused by a
dominant or recessive trait? dominant
9. How many children did individuals I-1 and I-2 have? 6
10. How many girls did II-1 and II-2 have? 2
How many have Huntington’s Disease? 2
11. How is individual III-2 and II-4 related?
niece-uncle
I-2 and III-5? grandma-grandson
12. Write the genotypes of each individual
on the pedigree.
I
II
III
IV
13. Write the generation on the pedigree numbers (roman numerals).
The pedigree to the above shows the passing on of Hitchhiker’s Thumb
in a family. Is this trait dominant or recessive? recessive
14. How do you know? Because parents III-4 and III-5 had to have
kids IV-2 and IV-4
15. How are individuals III-1 and III-2 related? mating
16. Name 2 individuals that have hitchhiker’s thumb. IV-2 and IV-4
17. Name 2 individuals that were carriers of hitchhiker’s thumb.
III-4 and III-5
18. Write the genotypes for each individual on the pedigree.
• 19
• a. Which characteristic is dominant? Black
• b. Which characteristic is recessive?
White
• c. Determine the genotypes of all
individuals. You will have three “A?”. Write
your Genotypes beneath each individual.
Interpreting a Pedigree
Generations
- Each row represents a generation.
- Each generation is marked using Roman
Numerals
- (I, II, III, IV)
Interpreting a Pedigree
On a pedigree the trait is shown by the colored
shapes
Generally if a shape is colored that person has
the trait
Parent Genotype Based on Child
If one or more child has the trait
AND
Parent shapes are blank
Parent genotype = heterozygous
Determining if the trait is Dominant or
Recessive

If one parent has disorder (colored) disorder
is dominant

If neither parent has to have the disorder
(blank) but children do, the disorder is
recessive and parents are heterozygous.
Parent with disorder (colored in) = dominant
Parent without disorder (blank) = recessive
Dominant
Or
Recessive?
Dominant because
The father has it
Dominant or Recessive
Recessive because parents do not have it
Dominant or Recessive?
Recessive because parents do not have it
Dominant or Recessive?
Dominant because one parent has it
Practice
Problem 1 and Problem 2
Problem 1
1.
2.
3.
4.
5.
I , II 1, II3, II 7, III3
Dominant
6
2
Huntington's = 1
Uncle
Grandmother1
Problem 2
1.
2.
3.
4.
5.
Recessive
Because the parents do not have it
Married
IV 1, IV3
III 1, III 2
Problem 3
Create a pedigree for the following:
1. Joe Marries Sue- they are carriers for the jumping disease
2. They have 4 kids: Jack, Zack, Luke and Sara
3. Zack and Sara have the jumping disease (recessive)
4. Jack marries Amy, she has the disease
5. They have Lorie, who is also affected
6. Sara marries Dan who is a carrier. Sara is pregnant
B. Punnett Square
Sara = rr
Dan = Rr
r
There is a 50% chance
Their baby will have
r
The disease
R
r
Rr
rr
Rr
rr
A. Make a pedigree for the family below.
1. Matt and Jennifer get married; Matt has hairy toes
(recessive)
2. They have 2 kids, Adam and Faith
3. Adam has hairy toes and Faith is a carrier
4. Faith marries Alex. They have 1 son. He does not have
hairy toes.
B. What is Jennifer’s Genotype? How do you know?
C. What is Alex’s Genotype? How do you know?
Exit
1.
2.
3.
4.
5.
How many generations are in this pedigree?
Is the trait in this pedigree dominant or recessive?
What are the genotypes of III 5 and III 6?
How many males are in generation II?
How many females are there total?
Chromosomes Determine Gender
XX = Female
XY = Male
Sex Linked Trait
a trait that is found
on either the X or Y
chromosome
Hemophilia is an
example of a sex
linked trait.
Hemophilia
a disease where
your blood doesn’t
clot.
Hemophilia only
occurs when all of
the X chromosomes
have a copy of the
recessive gene.
H
h
X X :female carrier
h
h
X X :female hemophiliac
H
X Y:normal male
h
X Y:hemophiliac male
SICKLE CELL
ANEMIA
Difference between
normal cells & sickle
cells
Sickle Cell
SS =
normal
Ss = carrier
(SC trait)
ss = sickle
cells
(lethal)
Sickle Cells tend to get stuck
easily in the circulatory
system.
Why would African
American’s be so
much more likely to
have Sickle Cell?
Regular red blood cells
infected by malaria
PEDIGREE
chart that shows
the relationships
within a family
Sample Pedigree
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Sample Pedigree
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Pedigree Basics
• Males are squares, females are
circles, and unborn babies are
triangles or octagons
• Shaded figures represent individuals
with the trait, a carrier could be 1/2
shaded
• Generations are numbered with roman
numerals (I, II, II, IV) from top to
bottom
ANTIBODY
a protein produced by white
blood cells in the body in
response to the presence of
an antigen, for example, a
bacterium or virus
ANTIGEN
a substance, usually a
protein, on the surface of
a cell or bacterium that
stimulates the production
of an antibody
Blood Groups
Quic kT i me™ and a
T IFF (Unc ompres s ed) dec ompres s or
are needed t o s ee thi s pi c ture.
Quic kT i me™ and a
T IFF (Unc ompres s ed) dec ompres s or
are needed t o s ee thi s pi c ture.
Blood group A
You have A antigens on the
surface of your red blood cells
and B antibodies in your blood
plasma.
Blood group B
You have B antigens on the
surface of your red blood
cells and A antibodies in
your blood plasma.
Blood Groups
Quic kT i me™ and a
T IFF (Unc ompres s ed) dec ompres s or
are needed t o s ee thi s pi c ture.
Blood group AB
You have both A and B antigens
on the surface of your red blood
cells and no A or B antibodies at
all in your blood plasma.
Blood group 0
Quic kT i me™ and a
T IFF (Unc ompres s ed) dec ompres s or
are needed t o s ee thi s pi c ture.
You have neither A or B
antigens on the surface of your
red blood cells but you have
both A and B antibodies in your
blood plasma.
Rh Factors
Quic kT i me™ and a
T IFF (Unc ompres s ed) dec ompres s or
are needed t o s ee thi s pi c ture.
Quic kT i me™ and a
T IFF (Unc ompres s ed) dec ompres s or
are needed t o s ee thi s pi c ture.
Many people have a
Rh factor on the
surface of their red
blood cells. This is
also an antigen and
those who have it are
called Rh+. Those
who haven't are called
Rh-.
Possible Blood
Groups
You can belong to either of
following 8 blood groups:
A Rh+
B Rh+
AB Rh+
0 Rh+
A RhB RhAB Rh0 Rh-
Transfusions
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
The transfusion will work if a person who is
going to receive blood has a blood group
that doesn't have any antibodies against the
donor blood's antigens.
QuickTi me™ and a
T IFF (Uncom pressed) decom pressor
are needed to see t his pict ure.
People with blood
group 0 are called
"universal donors"
and people with
blood group AB
are called
"universal
receivers.
PRACTICE TRANSFUSIONS
http://www.nobel.se/medicine/
educational/landsteiner/index.
html
200 B.C.
Humans “clone” trees by cuttings
1950
Humans clone frogs
1980’s
Humans clone mice!
1997
HUMANS CLONE SHEEP!!!
1998
Humans clone 8 copies of a cow!!!
20??
GENETIC
ENGINEERING
moving genes from one
chromosome of one
organism to the
chromosome of another
“Fat” Gene
CLONING
making an exact
copy of another
cell / organism
Dolly—the first cloned
sheep
Ian Wilmut,
the dude that
did it
Check out this short
movie that talks
about cloning…
A dividing cell
Read NYTimes Article
"Despite Warnings, 3 Vow to Go Ahead on Human
Cloning"
a. What did three proponents of human cloning
announce on August 7, 2001?
b. Where did they make this announcement?
c. Why did some scientists at the symposium object
to the proponents' announcement?
d. Why did Dr. Alan Colman object to the research
by these proponents being done in secret?
e. According to the article, what was the consensus
among the panel and most of those who
testified before it?
Read NYTimes Article
"Despite Warnings, 3 Vow to Go Ahead on Human
Cloning"
f. Who was "Dolly"?
g. What animals have been successfully cloned?
h. According to the article, what is involved in
cloning a human?
i. How did the three proponents say they would
address the possibility of genetic
abnormalities?
j. How did other experts at the symposium respond
to this statement?
k. Why do the proponents need to conduct their
research secretly?
•http://www.biology.arizona.edu/human_bio/activities/karyot
yping/karyotyping.html
•http://www.pathology.washington.edu/galleries/Cytogaller
y/cytogallery.html
•http://www.biology.iupui.edu/biocourses/N100/2k2humancs
omaldisorders.html
•http://www.biology.washington.edu/bsa/karyotypeS.html
•http://worms.zoology.wisc.edu/zooweb/Phelps/karyotype.html
AMNIOCENTESIS
A technique used to
determine the
genetic traits of a
baby before it is
Klinefelter Syndrome
• Have male genitalia and internal ducts, but
underdeveloped testes
• Do not produce sperm
• Slight enlargement of the breasts
• 47,XXY
• 1 out of every 500 male births
Turner Syndrome
•
•
•
•
•
•
•
Has female external genitalia
Underdeveloped ovaries
Short (under 5 feed)
Webbed Neck
Broad, Shield-like chest
45,X
1 out of every 3000 female births
Cri-du-Chat Syndrome
• Partial monosomy (part of 1 chromosome is lost)
• Loss of about 1/3 of the short arm of
chromosome 5
• Anatomical malfomrations (gastrointestinal and
cardiac complications)
• Mentally retarded
• Abnormal development of the larynx which
makes the baby’s cry sound like a cat’s cry
• 1 in 50,000 live births
Down Syndrome
•
•
•
•
•
•
•
•
•
BKA trisomy 21 (47, 21+); 3 copies of the 21st chromosome
Short
Small round heads
Protruding, furrowed tongues which cause mouth to remain partially
open
Retarded (IQ below 70)
Shortened life expectancy (<50)
Prone to reparatory disease and heart malformations
Have 15x higher chance of getting leukemia
Chance of having a baby with Down syndrome goes up as the
mother gets older