DIHYBRID CROSSES ( 2 traits)

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?

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

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

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

LAW OF __________________________ the factors are distributed to gametes independently of other factors INDEPENDENT ASSORTMENT Image modified from:

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

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

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

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

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

POSSIBLE PARENT GAMETES? RYRY ryry RyRy rYrY

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 RRYY RRYy RrYYRrYy RRYy RRyy RrYy Rryy RrYY RrYy rrYY rrYy RrYy Rryy rrYy rryy heterozygous dihybrid

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

PRACTICE MAKING GAMETES for DIHYBRID CROSSES

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

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

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

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