1. Warm Up 2/11 Sit with your baby partner.
What is an example of a chromosomal disorder?
What is an example of a gene disorder?

2. Important Dates Genetic Quiz! Baby Project DUE Next time!
You picked up a review at the door!
Six Weeks Test on 2/20!

3. Genetics Quiz

4. Types of Inheritance
Simple, Co-dominance, Incomplete Dominance, Multiple Alleles, Sex-Linked

5. Simple Dominance 1. Simple Dominance:
One Trait is expressed over another in the heterozygous condition.
Mendelian Genetics
Ex. Pure Tall X pure Short = Hybrid Talls T T t t

6. Incomplete Dominance
The heterozygous condition has a new phenotype – it is blended
Ex. Pure Red (RR) X Pure White(WW) = Hybrid Pink (RW)
Notice that they are both dominant traits R R W W

7. Snap Dragons Notice that the offspring are all pink.
What would happen if two Pink
Snapdragons mated? (RW X RW)
What would be the Phenotypic Ratio?
Genotypic Ratio?

8. Co- Dominance
Both traits are equally expressed in the heterozygous condition.
Ex Pure Black X Pure White = Hybrid Checkered B B W W

9. Chickens

10. COWS

11. Sickle Cell Anemia
Codominance between normal and sickle gene (S) and (N)
NN: Normal Hemoglobin
NS: Carrier (1/2 normal : ½ Sickled )
SS: has sickle cell anemia

12. Practice
A male who is a carrier for sickle cell anemia, is married to a female who is also a carrier. What is the chance that a child may have normal hemoglobin? Sickle Cell?

13. Polygenetic Inheritance
A non-Mendelian form of inheritance in which a particular trait is produced by the interaction of many genes
Ex. Height, Skin Color, Eye color, Hair color

14. Multiple Alleles Some traits have more than 2 possible alleles.
Ex. Human Blood type 3 alleles: IA, IB, i
The allele indicates the type of markers found on the blood cells.
Genotype(s)
Phenotype
IAIA, IAi,
A Type Blood
IBIB, IBi
B Type Blood
IAIB
AB Type Blood ii
O Type Blood

15. Why is type O the Universal Doner?

16. Lets practice
A female who is Heterozygous for type A blood, has children with a male who is type O blood.
What is the chance of their children having 0 type blood?

18. Blood Typing Practice
If a child has TYPE O Blood. What genotypes could the parents have?
List all possible crosses.

19. Sex-Linked Inheritance
Traits controlled by genes located on sex chromosomes.
The 23rd pair of human chromosomes determine the sex of an individual. ( can be identified on a karyotype)
T. H Morgan accidentally discovered while studying fruit flies.
Review: Males (XY) Females (XX)

20. Human Sex-Linked Disorders
1. Red-Green Colorblindness
2. Hemophilia A
3. Duchenne’s muscular Dystrophy

21. Colorblindness For sex-linked traits, you must write genotypes like:
XCXC: Normal color vision female
XCXc: Normal color vision female (carrier)
XcXc: Color-blind female
XCY: Normal Color Vision Male
XcY: Color-Blind Male

22. Example
Female with colorblindness has children with a normal vision male.
What are the genotypes and phenotypes of offspring?

23. What do you need to remember?
1. Males pass their X-linked allele to all their daughters. (never to sons)
2. Heterozygous females have a 50% chance of passing a recessive allele to all her children.
3. Males receiving the recessive X from mom will ALWAYS express the trait.
Why are males more likely to get a sex-linked disorder?

24. Sex-Linked Examples
Hemophilia is a disorder dependent on a sex-linked recessive gene (Xh ). Normal Blood is dominant (XH)
A. Find the genotype and phenotype ratios of a cross between a hemophiliac man and a homozygous normal woman.

26. Practice
Find a genotype and phenotype ratios of a cross between a normal woman, whose father was a hemophiliac, and a normal man.

27. Work on Baby Project!!
It’s due next time!!!