1. 5-13
Question of the Day
If a man has an X-linked recessive disorder and his mate does not carry the allele for it, _____ of their girls will be carriers. _____ of their boys will inherit the harmful allele. 

2. Review
Why are there more X sex linked traits?
Linked genes are usually …
Mutations in an organisms gametes = ?
Mutations that cause death = ? Example from class = ?
What type of mutation causes Down syndrome (2 correct answers)?

3. Assignment
5-12
Read 12.2 and answer #s on the bottom of page 248 – DUE tomorrow (Friday 5-13)

4. XA Xa XA Y Question of the Day 5-20
A female carrier of an X-linked recessive allele for a disorder hooks up with a normal male, their sons have a _____ chance of inheriting the disorder. _____ of their daughters will have it, but _____ of them are likely to be carriers. XA Xa XA
XAXA
XaXA Y
XAY
XaY

5. Pedigrees
Pedigree – diagram that shows how a trait is inherited over several generations
Squares = ?
Circles = ?

6. XX XrY Study the simple pedigree. The man is red (pink) because…?
The daughters are blue because …?
Is it possible to get a son that has Hemophilia or is a carrier? Explain!
If one of the sons hooks up with a female carrier, what will happen?
XrY XX

7. Pedigrees
Standard Key:

8. Reading a Pedigree: Are there carriers? IF YES – it’s recessive
IF NO – it’s dominant

9. Reading a Pedigree:
If it’s recessive, are there any male carrier? IF YES – it’s autosomal
IF NO – it’s X-linked

10. Reading a Pedigree:
If it’s dominant, analyze an affected son.

11. Question of the Day
What type of disorder is shown in the pedigree below? How do you know? Use your notes from Friday!
5-23
Are there any carriers?
Analyze an affected son (can a son get it from dad?)
What type of disorder?

12. Review
5-20
What type of disorder?

13. Hemophilia (X-linked recessive) Pedigree from Queen Victoria
What type of disorder?

14. Announcement: Questish quizish type deal will be Friday 5-27

15. X-Linked Traits Traits carried on the X chromosome
Who will show more X-linked disorders, males or females? Why?
Males – b/c they only have one X (XY) so it doesn’t matter if trait is dominant or recessive
Examples:
Colorblindness – carried on X-chromosome
Hemophilia – impaired blood clotting

16. Pedigrees
Carriers – people who carry an allele for a disorder, but do not have the disorder (Heterozygous)
Genetic disorders – any disease / disorder that has a genetic basis
Polygenic – characteristics that are influenced by several genes
Examples:
Skin color – six genes
Other examples – eye color, height, hair color

17. Pedigrees
Complex characters - characteristics that are influenced strongly by both environment and genes
Sun = darker skin
Height = several genes but also nutrition and disease

18. Multiple Alleles – genes that have three or more alleles (usually 2)
Example: Blood Type
What are the blood types?
ABO
Three alleles – IA, IB, i
Blood Types – A, B, AB, O

19. Review
Who will show more X-linked disorders, males or females? Why?
Linked genes are usually …
Germ-cell mutations = ?
Chromosomal mutations cause changes to chromosome ___ or ___. Example from class = ?
What is a pedigree?

20. Question of the Day
5-16
An example of a human trait that is polygenic and a complex character = _____ because...

21. Question of the Day
How do you identify a dominant genetic disorder on a pedigree (use notes page 5 if needed)?
5-24

22. Announcement: Questish quizish type deal will be Friday 5-27

23. Antigens – proteins, carbs etc on outside of red blood cells
Antibodies – immuno proteins that destroy unrecognized antigens

24.
“Blood typing activity” google – first link

25. Universal donor

26. Codominance – when both alleles are expressed in the phenotype (IA, IB – neither is dominant over the other – both carbs are produced on cell surface)
In codominance, you see both traits
Red cow x white cow = roan cow

27. Codominance

28. Incomplete dominance – mix between two parents (blend)
In incomplete dominance, you see a mix or blend of both traits
Example:
straight hair mom X curly hair dad = wavy haired child
Red flower x white flower = pink flower

29. Incomplete Dominance

30. X-Linked Traits (review)
Traits carried on the X chromosome
Who will show more X-linked disorders, males or females? Why?
Males – b/c they only have one X (XY) (doesn’t matter if trait is dominant or recessive)
Examples:
Colorblindness
Hemophilia

31. X-linked Dominant
If mother affected  equal chance of sons / daughters affected
If father affected  All daughters will have, sons ok
No carriers possible

32. X-Linked Recessive
If mother carrier  50% chance son will be affected, no daughters will have (females can be carriers)
If father affected  Sons will be ok, All daughters are carriers

33. Autosomal Dominant
Affected individual  50 / 50 chance of producing affected children
No carriers possible

34. Autosomal Recessive
Occurs if both parents are carriers (only 25% of the time)
Carriers possible

35. Handout

36. Single-Allele Traits – traits caused by one dominant allele
Huntington’s Disease –
caused by one dominant allele. Onset is so parents have children before they realize they have it
Forgetfulness, irritability, muscle spasms and mental illness, then death
Genetic testing now beginning to be used to determine if either parent has disease
skipped sp11

37. Pedigrees Standard Key: = normal male or
= carrier male (one bad allele + one good allele)
= affected male (has disease / disorder)
= normal female
= carrier female (one bad allele + one good allele)
= affected female (has disease / disorder)