You are studying two genes in roses. two alleles, r and r, affect petal color: r/r roses have red petals, and r/r roses have white petals; r is dominant and r is recessive. in addition, two alleles—, c and c, affect petal shape: c/c individuals have circular petals, and roses with the genotype c/c have square petals; c is dominant. if you cross two dihybrid roses (r/r ; c/c), progeny from this cross will have red circular petals and will have white circular petals.