Final answer:
A heterozygous plant with the genotype RrYy can produce four different allele combinations during meiosis, which are RY, Ry, rY, and ry, because of Mendel's laws of segregation and independent assortment.
Step-by-step explanation:
If a plant is heterozygous for both round (Rr) and yellow (Yy) seeds, during meiosis, four different allele combinations can be produced. According to Mendel's law of segregation, the alleles for each gene separate during gamete formation, meaning each gamete gets one allele for each gene. Moreover, Mendel's law of independent assortment states that alleles for different traits such as seed shape and color are distributed to gametes independently of one another.
The plant in question has the genotype RrYy for seed shape and color, yielding four possible combinations of alleles that can arise from meiosis: RY, Ry, rY, and ry. These combinations arise due to the random orientation of tetrads during meiosis I, which leads to the independent assortment of the alleles.