Question of the Day

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 1-8 on the bottom of page 248 – DUE tomorrow (Friday 5-13)

4. 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. 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? XX XrY

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 5-24 How do you identify a dominant genetic disorder on a pedigree (use notes page 5 if needed)?

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. http://nobelprize.org/educational_games/medicine/landsteiner/http://nobelprize.org/educational_games/medicine/landsteiner/ • “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 30-40 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)