 The developmental system, including the genome and its epigenetic regulation, responds flexibly to internal and external inputs.One example is condition-dependent gene expression, but regulatory systems also rely on physical properties of cells and tissues and exploratory behavior among microtubular, neural, muscular and vascular systems.Organisms inherit (i.e., receive from their predecessors) a diverse set of developmental resources, including DNA, epigenetic marks, organelles, enzymes, hormones, antibodies, transcription factors, symbionts, socially transmitted knowledge and environmental conditions modified by parents.