1. Cross a homozygous dominant green plant with a heterozygous green plant. What are the genotypic and phenotypic ratios.
Agenda for Tuesday Jan 3rd
Test stuff
Lab

2. Cross 2 heterozygous green pea seed plants
Cross 2 heterozygous green pea seed plants. What is the chance to have a yellow (recessive trait) pea seed?
Agenda for Wednesday Jan 4th
1. Complex patterns of inheritance
Incomplete and Co-dominance
Quiz Monday

3. Complete Dominance
a heterozygous individual’s phenotype will show dominant trait

4. Purebred red snapdragons were crossed with purebred white snapdragons all offspring were pink

5. Incomplete Dominance
one allele for a trait is not completely dominant over the other allele
Combined phenotype (blended)
R = allele for red flowers W = allele for white flowers
red x white ---> pink RR x WW ---> 100% RW

6. Co-dominance
In COdominance, the "recessive" & "dominant" traits appear together in the phenotype of hybrid (heterozygous) organisms

7. Practice
Set up genotypes for the phenotypes listed in each set. Remember that the "medium" trait is always heterozygous. a) Birds can be blue, white, or white with blue-tipped feathers. b) Flowers can be white, pink, or red. c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. D) A person can be tall, medium, or short.

8. 1. Write the genotypes for the pictured phenotypes 2
1. Write the genotypes for the pictured phenotypes 2. Show the cross between a star-eyed and a circle eyed. What are the phenotypes of the offspring? What are the genotypes?

9. 3. Show the cross between a circle-star eyed, and a circle eyed
3. Show the cross between a circle-star eyed, and a circle eyed. How many of the offspring are circle-eyed? How many of the offspring are circle-star eyed? Write the genotypic and phenotypic ratios. 4. Show the cross between two circle-star eyed. How many of the offspring are circle-eyed? How many of the offspring are circle-star eyed? How many are star eyed?

10. In humans, straight hair (SS) and curly hair (CC) are co-dominant traits that result in hybrids that have wavy hair (SC). Cross a Straight hair female with a wavy haired male. What are the chances of having a curly haired child? What are the chances of having a straight hair child? What are the chances of having a wavy hair child?
Agenda for Thursday Jan 5th 1. Sex Linked traits Quiz Monday – incomplete/codominance/sex linked traits/multiple alleles

11. Sex Determination
Thomas Hunt Morgan – studied fruit flies in the early 1900’s

12. Sex Determination
Observed that one pair of chromosomes was different between males and females
Large one named “X” chromosome
Smaller one named “Y” chromosome
XX = female; XY = male

13. XY XX X Y X X X X XX
Female XX
Female X XY
Male XY
Male Y
50% Female; 50% Male

14. Sex Linkage
Sex Linkage: the presence of a gene on a sex chromosome (X or Y)
X-linked genes: genes found on the X chromosome
X chromosome carries more genes
Y-linked genes: genes found on the Y chromosome

15. Fruit Fly Eye Color Fruit flies normally have red eyes
Red is dominant; white is recessive
A few males have white eyes

16. Morgan’s Fruit Fly Experiments
Red-eyed female (XRXR) x White-eyed male (XrY) XR XR
XRXr
XRXr
RESULTS:
F1 generation – all red-eyed Xr
XRY
XRY Y

17. Morgan’s Fruit Fly Experiments
Red-eyed female (XRXr) x Red-eyed male (XRY) XR Xr
RESULTS:
F2 generation – red-eyed and 1 white-eyed
** all white-eyed where males…why?
XRXR
XRXr XR
XRY
XrY Y

18. Morgan’s Conclusions
Gene for eye color is carried on the X chromosome = eye color is an X-linked trait
Y chromosome does not carry a gene for eye color
Red-eyed = XRXR, XRXr , XRY
White-eyed = XrXr, XrY

19. In humans colorblindness (b) is an example of a sex-linked recessive trait. A male without colorblindness marries a female who isn’t colorblind but carries the allele.
What are the phenotypes of the offspring?
What are the genotypes of the offspring?
What are the genotypic ratios?
What are the phenotypic ratios?
What is the percent chance of each genotype?
What is the percent chance of each phenotype?

20. In fruit flies red eye color (R) is dominant to white eyes (r) and is a sex linked trait.
A heterozygous red eye female mates with a red eye male.
What are the phenotypes of the offspring?
What are the genotypes of the offspring?
What are the genotypic ratios?
What are the phenotypic ratios?
What is the percent chance of each genotype?
What is the percent chance of each phenotype?

21. In fruit flies red eye color (R) is dominant to white eyes (r)
In fruit flies red eye color (R) is dominant to white eyes (r). Cross a heterozygous female with a white eye male. What are the phenotypic and genotypic ratios?
Agenda for Friday Jan 6th 1. Practice with sex linked traits 2. Multiple alleles Quiz Tuesday

22. In fruit flies red eye color (R) is dominant to white eyes (r) and is a sex linked trait. A heterozygous red eye female mates with a white eye male. How many males will have white eyes?

23. In humans colorblindness (b) is an example of a sex-linked recessive trait. A male with colorblindness marries a female who isn’t colorblind and does not carry the allele. What is the chance they will have a child that is colorblind?

24. Multiple Alleles
Multiple alleles – traits determined by more than 2 alleles
Increases possible number of genotypes & phenotypes
We have 2 alleles (1 from mom, 1 from dad)
Blood groups (ABO), O is recessive (i allele)
ALLELE IA IB i
CODES FOR Type "A" Blood Type "B" Blood Type "O" Blood

25. GENOTYPES IAIA IAi
RESULTING PHENOTYPES Type A Type A
IBIB IBi
Type B Type B
IAIB
Type AB ii
Type O

26. More alleles means more combinations
there are 6 different genotypes & 4 different phenotypes for blood type
2 genotypes for both "A" & "B" blood --- either homozygous (IAIA or IBIB) or heterozygous with one recessive allele for "O" (IAi or IBi).
The only genotype for "O" blood is homozygous recessive (ii).
And lastly, what's the deal with "AB" blood?  What is this an example of?  The "A" trait & the "B" trait appear together in the phenotype.

28. Problems
A woman with Type O blood and a man who is Type AB have are expecting a child.  What are the possible blood types of the kid?
What are the possible blood types of a child who's parents are both heterozygous for "B" blood type?

29. One More
What are the chances of a woman with Type AB and a man with Type A having a child with Type O?

30. What are the chances of a woman with Type AB and a man with Type O having a child with Type O?
Agenda for Monday Jan 9th
Review
Video
Quiz Tomorrow

31. What are the chances of a woman with Type AB and a man with Type AB having a child with Type A?
Agenda for Tuesday Jan 10th
Quiz
Breeding styrofoam monsters Lab
Quiz/test Friday

32. Epistasis
Epistasis – one allele hides/suppresses another allele

33. Polygenic Phenotype depends on alleles in multiple genes
Skin color, height, eye color
Continuous progression in expression of traits