1. Unit 2:

2. Autosomal and SL Diseases
Genetic diseases are caused by a “bad” gene. Passed down from parents to children. Genetic diseases are either autosomal or sex-linked.

3. Autosomal and SL Diseases
Autosomal disease: a disease that is carried on the first 22 chromosome pairs. (like hair color or strong hand). (Cystic fibrosis is an autosomal trait.)

4. Sex chromosomes
XY = Male
XX =Female FEMALE

5. Autosomal and SL Diseases
If you have a Y you are a guy!

6. Autosomal and SL Diseases
Sex-linked disease: a disease that is carried on the X chromosome.
Colorblindness and sickle cell are sex-linked disease.

7. Autosomal and SL Diseases

11. Autosomal and SL Diseases
Sex-linked diseases are carried on the X because the Y chromosome is very small.
X chromosome
Y chromosome
X chromosome
Y chromosome
X chromosome
Y chromosome

12. Introduction to Pedigrees
A pedigree is a tool used by scientists that shows how a genetic disease is passed down through a family.

13. Pedigrees: Figure it out!
Directions and Expectations:
Read and answer the questions with your group.
Raise you HAND for questions.

14. Pedigree Parts Square = Male Circle = Female Horizontal lines =
marriage
Vertical lines =
offspring

15. Pedigree Parts
Roman numerals =
Family generations

16. Pedigree Parts
Shaded shapes = Trait
Un-shaded shapes = no trait

17. Pedigrees
Scientists can use pedigrees to determine whether a disease is autosomal or sex-linked.

18. Pedigrees: Sex-linked
Trick: MANY more men sick then woman. (because it ONLY takes 1 bad X to make a man sick)
YES  sex linked
No  autosomal

19. Sex-linked Disorders
More males affected than females

20. Pedigrees: Autosomal
Trick: Roughly equal number of males and females affected.
Every sick kid has 1 sick parent  autosomal dominant
Not every sick kid has 1 sick parent  autosomal recessive

21. Autosomal Dominant

22. Autosomal recessive

23. In some cases…
You will see pedigrees with half-shaded squares or circles, this means the trait is autosomal recessive and the half-shaded individual is a carrier (heterozygous)

24. For coming slides… Expectations:
Discuss in your groups whether each of the following is a Sex-linked of Autosomal disease.
If autosomal, decide whether it is dominant or recessive.
Write your answers in your notes.

31. Practice Time! 31

32. Exit Ticket
1. The pedigree chart shows the appearance of a trait in several human generations. Which inheritance pattern does this trait follow?
A  autosomal dominant
B  autosomal recessive
C  sex-linked dominant
D  sex-linked recessive