. "A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of an organelle within a cell. An organelle is an organized structure of distinctive morphology and function. Includes the nucleus, mitochondria, plastids, vacuoles, vesicles, ribosomes and the cytoskeleton. Excludes the plasma membrane." . . "organelle organization and biogenesis" . "organelle organization" . "organelle organisation" . . . . . . . . . . . . . . . . . . . . . . . . . . . .