*Any of the membrane-enclosed structures within a eukaryotic [[cell]]. Examples incluede the [[nucleus]], [[endoplasmic_reticulum|endoplasmic reticulum]], and [[mitochondria]]. | *Any of the membrane-enclosed structures within a eukaryotic [[cell]]. Examples incluede the [[nucleus]], [[endoplasmic_reticulum|endoplasmic reticulum]], and [[mitochondria]]. |