1. Welcome Back!
Tracey has three brothers. One of Tracey's brothers has sickle-cell anemia, a disease caused by a recessive allele. She, her parents, and the other children do not have it. If Tracey's parents have another child, what is the chance that the child will have sickle-cell anemia? A.0% B.25% C.50% D.75%

2. Going Beyond Mendelian Genetics
Tall or Short

3. ?

4. Where did the grey mouse come from?
Bw X Bw = BB (25%) + Bw (50%) + ww (25%)
Dominant (Black)
Heterozygous (Black)
Recessive (White)
Mendelian Genetics
Where did the grey mouse come from?

5. Co-Dominance and Incomplete Dominance

6. Incomplete Dominance does not follow Mendel’s Rules
Bb X Bb = BB (25%) + Bb (50%) + bb (25%)
Dominant Incomplete Recessive

7. Bb X Bb = BB (25%) + Bb (50%) + bb (25%)
According to Gregor Mendel:
Genotypes: 25% BB 50% Bb 25% bb
Phenotypes: 75% Black 25% White
What about grey?!?!?!?!?!
Bb X Bb = BB (25%) + Bb (50%) + bb (25%)

8. BW X BW = BB(25%) + BW(50%) + WW(25%)
Instead of writing it that way, we use a different capital letter for both. This is because neither is dominant over the other.
BW X BW = BB(25%) + BW(50%) + WW(25%)
Genotypes: 25% BB 50% BW 25% WW
Phenotypes: 25% Black 50% Grey 25% White
This ONLY works if the problem tells you its co or incomplete dominance. B W B B B B B W W WW W

9. Incomplete Dominance
A cross between organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the parental traits. 
red x white ---> Pink

10. Incomplete Dominance
R = allele for red flowers W = allele for white flowers red x white ---> pink  RR x WW ---> 100% RW

11. Incomplete Dominance

12. red x white ---> red & white spotted
Co-Dominance
red x white ---> Pink
Co: Together, or Shared
Coexist- live together
Co-dominance- The"recessive" & "dominant" traits appear together in the phenotype of hybrid organisms. 
red x white ---> red & white spotted
Co-Captains

13. Co-Dominance red x white ---> red & white spotted BOTH!!!
R = allele for red flowers  W = allele for white flowers red x white ---> red & white spotted  RR x WW ---> 100% RW

14. What Do We Have Here?
BB X WW BB- Black White- White Co-dominance: White and Black

15. What Do We Have Here?
Theoretically….. Beaver X Duck? Co-Dominance: Platypus

20. 1. Traits seen “together”
Incomplete Dominance
Co-Dominance
Mixture
Blend
3rd or New Phenotype
1. Traits seen “together”

21. Bonus Material
sex-linked trait -A trait associated with a gene that is carried only by the male or female parent.
Ex: In humans, the gene for colorblindness is carried by the X-chromosome.