Dihybrid Punnett Square What is it? A graphical grid showing the potential offspring allele combinations for two genes each having two alleles.

Cross parents that are heterozygous for pod color (Gg) and seed color (Yy). Both parents are GgYy!!! YIKES!!!!! Hint: FOIL OFFSPRING PARENT GY Gy gY gy P A R E N T GY GGYY GGYy GgYY GgYy Gy GGYy GGyy GgYy Ggyy KEY: GG = Green pod Gg = Green pod gg = yellow pod YY = yellow seed Yy = yellow seed yy = green seed gY GgYY GgYy ggYY ggYy gy GgYy Ggyy ggYy ggyy

Interpreting a Punnett Square What does it tell us? GGYY = green pod; yellow seed ggyy = yellow pod; green seed Can you do the rest??? PARENT GY Gy gY gy P A R E N T GY OFFSPRING GGYY GGYy GgYY GgYy Gy GGYy GGyy GgYy Ggyy KEY: GG = Green pod Gg = Green pod gg = yellow pod YY = yellow seed Yy = yellow seed yy = green seed gY GgYY GgYy ggYY ggYy gy GgYy Ggyy ggYy ggyy

GY Gy gY gy GY Gy gY gy What are the ratios of phenotypes? 9 Green pod; yellow seed 3 Green pod; green seed 3 Yellow pod; yellow seed 1 Yellow pod; green seed 9:3:3:1 PARENT GY Gy gY gy P A R E N T GY OFFSPRING GGYY GGYy GgYY GgYy Gy GGYy GGyy GgYy Ggyy KEY: GG = Green pod Gg = Green pod gg = yellow pod YY = yellow seed Yy = yellow seed yy = green seed gY GgYY GgYy ggYY ggYy gy GgYy Ggyy ggYy ggyy