anthony triplin steve jean jude saint-jean february 1, 2010 period:3
TRANSCRIPT
HEMOPHILIA
Anthony TriplinSteve Jean
Jude Saint-Jean
February 1, 2010
Period:3
Hemophilia
Blood does not clot as quickly Most common in males Also known as Christmas disease Double vision, repeated vomiting, extreme
fatigue Only males get type A and B Females get type C Type C less common
Location of Hemophilia
Located on X chromosome
Mode of Inheritance
Hemophilia is sex linked/ x-linked Can only be passed down on X chromosome Hemophilia A ( 1 in 10,000 male births, 1 in
100,000,000 female births)
Alleles Two alleles for each gene Half from your mom and half from your dad A capital letter for dominant allele and a lower-case
letter for the recessive allele Dominant allele takes over a recessive allele Recessive produces only when its paired allele is
identical A X-linked dominant chromosome is represented as XH
A X-linked recessive chromosome is represented as Xh
Hemophilia Punnett Squares
XH Y
XH
Xh
XHXH XHY
XHXh XhY
•Punnett squares are used to show the probability of receiving a genetic disorder from a parent.
YXh
XH
XH
XHXh XHY
XHXh XHY
Xh Y
XH
Xh
XHXh XHY
XhXh XhY
Male w/ hemophilia and female non-carrier Male w/ hemophilia and female carrier
Homozygous Dominant
Heterozygous Dominant Homozygous
Recessive
Normal Male and female carrier
Punnett Square Probability
Ratios:1 : 1 : 1 : 1
1 XHXH : 1 XHXh : 1 XHY : 1 XhY
Percentages:
25% : 25% : 25% : 25%
25%XHXH : 25% XHXh : 25% XHY : 25%XhY Normal Male and female carrier
XH Y
XH
Xh
XHXH XHY
XHXh XhY
Punnett Squares Genotypes and Phenotypes
What do the letters mean ?•Uppercase letters represent dominant genes•Lowercase letters represent recessive genes•H is the dominant allele •h is are the recessive allele
Phenotype/What We SeeXHXH = Non CarrierXHXh = CarrierXHY= NormalXhY= Hemophilia
Genotype/What Is In Our GenesXHXH is the Homozygous dominantXHXh is the Heterozygous dominantXhY is the Homozygous recessive
Normal Male and female carrier
XH Y
XH
Xh
XHXH XHY
XHXh XhY
Genotype/Phenotype Probability
•Phenotype= The observable characteristic of an organism (Expression of genes)
-Ratios- 1 XHXH: 1 XHXh: 1 XHY: 1XhY- Percentages- 25% With Hemophilia
75% Without Hemophilia
•Genotype- The specific Allele makeup of an organism
- Ratios- 1 XHXH: 1 XHXh: 1 XHY: 1XhY- Percentages- 25%XHXH: 25% XHXh: 25% XHY: 25%XhY
Punnett square of a Normal Male and a Carrier Female
XH Y
XH
Xh
XHXH XHY
XHXh XhY
Student PracticeNow you try!
Genotype:Ratio: 2 XHXh : 2 XHY
Percentage: 50% Hemophilia Carrier 50% Normal
Phenotype:Ratio: 2 XHXh : 2 XHY
Percentage: 50% HY 50% hY
XH
Xh
XHXh
XHXh
XHY
For example: Eye color
Y
XH XHY
THREE GENERATION X-LINKED PEDIGREE CHART
White= Person is fine. May of two “healthy genes.”Black= Person is affected. Has 2 “bad” genes.
How to read:
Circle= FemaleSquare= Male
Shaded Circle= Female Hemophilia CarrierShaded Square= Male hemophiliac
Student Practice:
How to read an X- Linked Pedigree Chart.
Key: Square= MaleCircle= Female
Red Square= Male hemophiliacYellow Circle= Female carrier
Joe Jan
Marc Cindy Dan
Tom Jr.Lisa
You think you know X- linked Pedigree’s? If so:1. Who is the main source of the hemophilia in this family?2. How many people in this chart DO NOT have any form of
hemophilia?3. If Marc were to have children with a normal female, what
are the odds of one of them having some form of hemophilia?
TomKayla