Dihybrid Cross Notes Looking at 2 traits

Steps to Solve a Dihybrid Cross In race horses, black hair (B) and a trotting gait (G) are dominant traits. Recessive traits are chestnut hair (b) and a pacing gait (g). Determine the possible offspring from a cross between two heterozygous black trotters. Step 1: Determine the letter for each trait. B = black hair b = chestnut hair G = trotting gait g = pacing gait

Step 2: Determine the genotypes for both parents. Determine the possible offspring from a cross between two heterozygous black trotters. BbGg X BbGg

Step 3: Set up the Punnett Square Remember FOIL from Algebra (First, Outside, Inside, Last). BbGg X BbGg BG Bg bG bg BG Bg bG bg

Step 4: Fill in the Punnett Square Begin by filling in the B’s and then go back and fill in the G’s. BG Bg bG bg BG Bg bG bg BBGG BBGg BbGG BbGg BBgg Bbgg bbGG bbGg bbgg