Practice Problems: Dihybrid Cross
Background Information:
Trait Dominant Recessive
Plant Height Tall (T) Short (t)
Pod Shape Smooth (S) Wrinkled (s)
Pod Color Yellow (Y) Green (y)
Seed Coat Gray (G) White (g)
1. Write down the phenotypes for each of the following genotypes.
a. SS ________________________________________________
b. Yy ________________________________________________
c. Gg ________________________________________________
d. Tt ________________________________________________
e. TtGg ________________________________________________
f. SSyy ________________________________________________
g. yyTT ________________________________________________
2. Write down the possible genotypes for each of the possible phenotypes.
a. Smooth pods ________________________________________________
b. Green pods ________________________________________________
c. Tall plants ________________________________________________
d. Tall plant and Green pods ________________________________________________
e. Wrinkled and short ________________________________________________
f. Gray seeds and smooth pods ________________________________________________
3. Use a punnett square to complete the following cross. YyTt and yyTt . What are the genotype and phenotype
ratios?
