1. Monday 1/27/14 Grab a Bellwork sheet and begin on this problem.
Incomplete Dominance
In 4 o'clock flowers, the alleles for red and white flowers show incomplete dominance (RR=red, WW=white, RW=pink). What would be the possible outcomes of a cross between a pink flower and a pink flower?

2. Today Punnett square mastery Dihybrid cross Blood Types
Quiz on Friday 1/31

3. Using Letters Complete Dominance Incomplete Dominance/Codominance
Use same letter as capital and lowercase
Ex. T – dominant t – recessive
Ex. R – dominant r – recessive
Incomplete Dominance/Codominance
Use only capital letters!! Use different letters for each allele
Ex. R – Red W – White
Ex. B – Brown T - Tan

4. Genotype/Phenotype Genotype = 2GG: 2Gg: 0gg
A green pea plant (GG) is being crossed with a green pea plant (Gg). Yellow is the recessive color
G G GG Gg G g
Genotype = 2GG: 2Gg: 0gg
Phenotype = 4 Green pea plants: 0 yellow plants

5. Genotype/Phenotype Genotype = 1 BB: 2Bb: 1 bb
Two heterozygous white (brown fur is recessive) rabbits are crossed
B b BB Bb bb B b
Genotype = 1 BB: 2Bb: 1 bb
Phenotype = 3 White rabbits: 1 brown rabbit

6. Chickens!
In some chickens, the gene for feather color is controlled by codominance. The allele for black is B and the allele for white is W. The heterozygous phenotype is known as erminette.
a. What is the genotype for black chickens? ____ b. What is the genotype for white chickens? ____ c. What is the genotype for erminette chickens? ____
What would the offspring look like when crossing an erminette chicken and a black chicken? BB WW BW
50% BB and 50% BW

7. Co-dominance
In shorthorn cattle, when a red bull (RR) is crossed with a white cow (WW), all the offspring are roan— a spotted, red and white or milky red color.
1. What offspring are expected from mating a roan bull and a roan cow?
2. What phenotypes would you expect from a cross between a red bull and a white cow?
How do we know the difference between codominance and incomplete dominance?
25% RR, 50% RW, and 25% WW
100% Roan

8. 2 generations
A pea plant homozygous dominant (RR) for round seeds is crossed with a homozygous recessive (rr) wrinkled seeds pea plant. What is the phenotype of the offspring?
The above offspring were allowed to self-pollinate and produce offspring of their own. What are the genotypes and the phenotype ratio of this F2 generation?
RR and rr are called pure breeds. If they cross, they produce only one genotype Rr. This genotype can then self pollinate. The typical ratio when you cross a hybrid with a hybrid is 1:2:1 genotype and 3:1 phenotype
25% RR, 50% Rr, and 25% rr

9. Books
Read page 317 in your books.

10. Dihybrid crosses
A pea plant that is tall (TT) and has round seeds (RR) is crossed with a short plant (tt) with wrinkled seeds (rr).
What are the genotypes of the parents?
What are the possible combinations of alleles for each parent?
What will be the genotype and phenotype ratio for this cross?
This F1 generation is allowed to self pollinate and creates an F2 generation. What are the phenotypes?
TTRR and ttrr
TtRr
9:3:3:1

11. Tuesday 1/28/14
In some cats the gene for tail length shows incomplete dominance. Cats with long tails and cats with not tails are homozygous for their respective alleles. Cats with one long tail allele and one no-tail allele have short tails. What are the offspring of a cross between a short tail cat with a no-tail cat?
Draw a punnett square and list the genotypes and phenotypes.

12. Today More dihybrids Sex linked and Multiple allele Activity
Quiz on Friday

13. Homework from yesterday

14. Another cross
A tall white (Ttrr) plant is crossed with a short red (ttRR) plant.
What are the combinations of alleles for each parent?
What are the genotypes and what is the phenotype ratio for this cross?
Use the FOIL method
TtRr and ttRr 1:1

15. Blood Types Human Blood types follow a pattern of Codominance.
There are two dominant alleles IA and IB.
There is one recessive allele i

16. Blood Type (Phenotype) Genotype Can donate blood to:
Can receive blood from: O ii
A,B,AB and O
(universal donor) AB
IAIB
O, AB
(universal receiver) A
IAIA or IAi
AB, A
O, A B
IBIB or IBi
AB, B
O, B
What is the genotype of a man with heterozygous A blood? How about heterozygous B blood? O Blood? AB blood?
Multiple Alleles

17. ABO
What are the possible blood types from a cross between a heterozygous A man and a heterozygous B woman?
AB, A, B, O

18. Sex Linked Inheritance
Genes located on a sex chromosome.
Males XY
Females XX
Genes on Y chromosome only passed from father to son.
Genes on X chromosome are found in both sexes. Men have only 1 X chromosome.
For recessive alleles found on the X chromosome, males need only 1 copy in order for the disease to show. Females need 2 copies of the recessive allele because they have 2 chromosomes.

19. Color Blindness Females have 3 genotypes and phenotypes:
XHXH is normal female without disorder
XHXh is female who is a “carrier”
XhXh is female who has the disorder
Males have 2 genotypes and phenotypes
XHY is a normal male without disorder
XhY is male who has disorder
What are the genotypic and phenotypic ratios for a cross between a “carrier” female and normal male?
1 normal female: 1 carrier female; 1 normal male: 1 male w/ disorder

20. Problems
Work with your table partner to solve the problems on the half-sheets.
I will hand out these out.

21. Face Lab