Defined: Crossing of two traits 16 possible outcomes Dihybrid Punnett Squares Defined: Crossing of two traits 16 possible outcomes Use the “FOIL” method from math F = First O = Outside I = Inside L = Last Tips: Place capital letters first 2) Group the same letters together

RY Ry ry RY RrYy RrYY RRYY RRYy Ry Rryy RRYy RRyy RrYy rY RrYY RrYy Cross two heterozygous dominant Round, Yellow seeds with each other. R r Y y x R r Y y Key: R = Round Y = yellow r = wrinkled y = green RY Ry rY ry RY RrYy RrYY RRYY RRYy Ry Rryy RRYy RRyy RrYy rY RrYY RrYy rrYY rrYy RrYy ry Rryy rrYy rryy

R = Round Y = Yellow 1 RRYY 4 RrYy 1 rrYY 9 Round, Yellow Seeds 2 RRYy r = wrinkled Y = Yellow y = green List all the Possible Genotypes: List all the Possible Phenotypes: 1 RRYY 4 RrYy 1 rrYY 9 Round, Yellow Seeds 2 RRYy 1 RRyy 2 rrYy 3 Round, Green Seeds 2 RrYY 2 Rryy 1 rryy 3 Wrinkled, Yellow 1 Wrinkled, Green

1 RRYY 4 RrYy 1 rrYY 9 Round, Yellow Seeds 2 RRYy 1 RRyy 2 rrYy Genotypes: Phenotypes: 1 RRYY 4 RrYy 1 rrYY 9 Round, Yellow Seeds 2 RRYy 1 RRyy 2 rrYy 3 Round, Green Seeds 2 RrYY 2 Rryy 1 rryy 3 Wrinkled, Yellow 1 Wrinkled, Green What is the probability of getting: Competely homozygous recessive seed? 1/16th Completely heterozygous plants? 4/16th Homozygous round seeds? What is the probability of getting: Wrinkled, yellow seeds? 3/16th Green seeds? 4/16th Three round, yellow seeds? 9/16 x 9/16 x 9/16 = 729/4096 or 17.8%

Man: Hemophiliac, Carrier of sickle cell disease Woman: No history of hemophilia, Carrier of sickle cell

Man: Hemophiliac, Carrier of sickle cell disease Woman: No history of hemophilia, Carrier of sickle cell

Girl with sickle cell disease? 2/16

Hemophiliac boy with sickle cell disease? 0/16

Girl who carries hemophilia and sickle cell disease? 4/16

Child with sickle cell disease? 4/16