1. DIHYBRID CROSSES ( 2 traits) http://mac122.icu.ac.jp/BIOBK/BioBookgenintro.html

2. Mendel also asked the question? Does the gene that determines if a seed is round or wrinkled have anything to do with the gene for seed shape? Must a seed that is yellow also be round?

3. MAKING A CROSS with ___________________= ____________________ A Punnett square for a DIHYBRID CROSS looks like this: DIHYBRID CROSS TWO gene traits

4. Go to Section: Section 11-3 Figure 11-10 Independent Assortment in Peas

5. 1. ___________ what _________________ are 2. ________correct__________ square __________ 3. ______ possible_______________________ 4. ______ boxes with _____________________ 5. Determine ____________of_____________& ____________ LET’S MAKE A DIHYBRID CROSS HOMOZYGOUS YELLOW ROUND rryy HOMOZYGOUS GREEN WRINKLED Figure out parent alleles Choose Punnett size Put in parent gametes Fill in offspring combinations probabilities phenotypes genotypes RRYY

6. LAW OF __________________________ the factors are distributed to gametes independently of other factors INDEPENDENT ASSORTMENT Image modified from: http://anthro.palomar.edu/mendel/mendel_1.htm

7. R R Y YR R Y Y HOMOZYGOUS ROUND YELLOW PRACTICE MAKING GAMETES WHAT ARE THE POSSIBLE GAMETES THIS PARENT CAN MAKE ? Each gamete should get one of each kind of gene ___________ ____________ _____________ _____________ R YR Y R YR Y R YR YR YR Y

8. r r y yr r y y HOMOZYGOUS WRINKLED GREEN PRACTICE MAKING GAMETES WHAT ARE THE POSSIBLE GAMETES THIS PARENT CAN MAKE ? Each gamete should get one of each kind of gene ___________ ____________ _____________ _____________ r y r yr y r yr yr yr y

9. R r Y yR r Y y HETEROZYGOUS ROUND YELLOW PRACTICE MAKING GAMETES WHAT ARE THE POSSIBLE GAMETES THIS PARENT CAN MAKE ? Each gamete should get one of each kind of gene ___________ ____________ _____________ _____________ R YR Y r yr y r Yr YR yR y

10. ry RY 100% of offspring = _______ genotype _______________________ phenotype RrYy ROUND YELLOW RrYy RrYy RrYyRrYy RrYy RrYy

11. R r Y yR r Y yR r Y yR r Y y HETEROZYGOUS ROUND YELLOW MAKE ANOTHER CROSS X

12. POSSIBLE PARENT GAMETES? RYRY ryry RyRy rYrY

13. RYRyrYry RY Ry rY ry Sign of a ______________________ cross is a _____________ ratio in offspring. 9:3:3:1 ____ Round & Yellow ____ Round & green ____ Wrinkled & yellow ____ wrinkled & green 9 3 3 1 RRYY RRYy RrYYRrYy RRYy RRyy RrYy Rryy RrYY RrYy rrYY rrYy RrYy Rryy rrYy rryy heterozygous dihybrid

14. __________ratio is a clue that it’s a ____________________________cross ____ ____________ TRAIT 1 ; ____________ TRAIT 2 ____ ____________ TRAIT 1; _____________ TRAIT 2 9 3 3 1 9:3:3:1 HETEROZYGOUS TWO gene dominant dominant recessive recessive dominant recessive

15. PRACTICE MAKING GAMETES for DIHYBRID CROSSES http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html

16. pure round & pure tall = __________ ____ ____ ___________ What gametes can it produce? What are the possible gametes?   R R T T R T   R TR TR TR T

17. Heterozygous Tall = __________ & pure round ____ ____ ___________ What gametes can it produce? What are the possible gametes?   T t R R T R   t Rt Rt Rt R

18. Hybrid tall = __________ & pure wrinkled ____ ____ ___________ What gametes can it produce? What are the possible gametes?   T t r r T r   t rt rt rt r

19. Heterozygous tall = __________ & hybrid round ____ ____ ___________ What gametes can it produce? What are the possible gametes?   T t R r T RT r   t rt rt Rt R