Final answer:
The results obtained by Mendel can be explained by the mechanism of inheritance known as Mendelian genetics, where each trait is controlled by discrete units called genes. The different combinations of alleles for seed shape and seed color result in various phenotypes in the F2 generation.
Step-by-step explanation:
The results obtained by Mendel after self-pollination in pea plants with round, yellow seeds can be explained by the mechanism of inheritance known as Mendelian genetics. According to Mendel's experiments, each trait is controlled by discrete units called genes, which come in pairs (alleles). In this case, the genes for seed shape are represented by the alleles R for round and r for wrinkled, and the genes for seed color are represented by the alleles Y for yellow and y for green.
When round, yellow seeds are self-pollinated, the genotype of the parent plants is RYRY. As a result, all the progeny of the F1 generation will also have round, yellow seeds because the dominant alleles are expressed in the phenotype. However, when the F1 generation is self-pollinated, the different combinations of alleles can give rise to various phenotypes in the F2 generation. Thus, we observe round, yellow seeds (RYRY), round, green seeds (RYry), wrinkled, yellow seeds (rrYY), and wrinkled, green seeds (rryy).