Biology

   In a plant species, leaf shape is controlled by two genes (A and B). The presence of at least one dominant allele of each gene (A_B_) results in oval - shaped leaves. The presence of a homozygous recessive genotype for either gene (aaB_ or A_bb) leads to round - shaped leaves, and the double homozygous recessive (aabb) leads to lance - shaped leaves. If two plants with the genotype AaBb are crossed, what is the ratio of the different leaf - shaped phenotypes in the offspring?