1. Genetic Disorders

2. Lesson Objectives Minds ON Yesterday’s Recap Genetic Disorders Game
Last minute prep for presentations?
REMINDERS:
Quiz TODAY!
Presentations tomorrow!
Thursday: Review
Friday: Test

3. Minds ON
Draw a pedigree for the following: Sarah is a carrier for hemophilia. She marries Rob and they have two sons, Michael and Will. Both sons have hemophilia. Is it possible that only one or neither could’ve had hemophilia? Explain.

4. Yesterday’s Recap
Autosomal Disorders/Traits: Traits / disorders passed on through the autosomal (body) chromosomes
Autosomal Dominant: One or two copies of the trait was passed from one or both parents to cause the trait to appear
Autosomal Recessive:Two copies of the recessive trait must be passed on from both the parents in order for it to appear
Gender: XX = Female; XY = Male
X-Linked Traits / Disorders: Trait / disorder passed on through the female (X) sex chromosome; more likely to occur in males (hemophilia, colour blindness, muscular dystrophy)
Pedigrees: Shows family information; can trace genetic disorders

5. Karyotypes: Humans chromosome set can be broken into two types.
Autosomes: 22 pairs – sex chromosomes
Sex chromosomes: X and Y
All 46 can be seen in a karyotype.

6. Types of Inheritance Autosomal Dominant Autosomal Recessive
(does not skip a generation)
Autosomal Recessive
(can skip a generation)
X-Linked Recessive
(affects mostly males)

7. Genetic Defects
Today we will be looking at two types of genetic defects:
Single Gene Defects: Changes or mutations in genes of either autosomes or sex cells (female: X-linked recessive). These can be caused by mutations in the genes (heritable factors), environmental agents (virus, alcohol use while pregnant) or both.
Chromosomal Defects: Inherited abnormality involving whole chromosomes (aneuploidy – absence of a single chromosome or presence of an extra chromosome)

8. An Example a of Single Gene Defect:
Albinism:
Characteristics:
Pale skin, light hair, pink coloured eyes
Means of Inheritance:
Autosomal recessive
Cause:
Hereditary inability to produce skin, hair, eye pigment

9. An Example of a Chromosomal Defect:
Down Syndrome
Characteristics:
Abnormal facial, foot and hand features; Varying developmental challenges; 1 in 700 live births
Means of Inheritance/Cause:
Trisomy: Extra chromosome on #21

10. Genetics Defects Worksheet
Fill in the following table using the textbook (p. 205)
You will need this for the next activity…

11. Quiz Time
Good luck!

12. Genetics Bingo Get a card
Randomly place the names of the 14 genetic disorders on your sheet
I will say the symptoms and you have to guess the name of the disorder
Only use your table as a last resort!