It is easy to see how an infant child relates to the parent. With respect to overall pattern, it is essentially the adult in miniature: 2 arms, 2 legs, 10 ngers, and 10 toes. e same is not true when one compares a newly emerged plant seedling to the adult. e adult plant body plan is oen a highly elaborated structure with multiple lateral appendages and organs. ese structures may be underdeveloped or completely lacking in the newly germinated seedling. is is because much of the adult plant body is patterned postembryonically through the action of coordinated groups of stem cells in the shoot and root apices: the shoot and root apical meristems (SAM and RAM, respectively). Postembryonic development of the adult body plan allows the plant the plasticity to adjust its overall structure, to optimize the acquisition of resources like light and water, and to respond appropriately to biotic and abiotic signals.