The gene controlling starch synthesis in pea shows a small degree of pleiotropy. Starch synthesis in pea seeds is controlled by one gene. It has two alleles B and b. Starch is synthesized effectively by BB homozygotes and therefore, large starch grains are produced. In contrast, bb homozygotes have lesser efficiency in starch synthesis and produce small starch grains. After maturation of the seeds, BB seeds are round and the bb seeds are wrinkled. Heterozygotes Bb form round seeds but the starch grains are of intermediates size. It starch grain size is considered, Bb seed shows incomplete dominance but if seed shape is considered, B allele is dominant and b is recessive.