To understand life phenomena, we must consider form, structure, organization, motion, and the roles they play in "living" functions. This book explores such elements through mathematical methods. Beginning with an overview of dynamical systems and stochastic processes, the chapters that follow build on experimental advances in quantitative data in cellular processes to demonstrate the applications of these mathematical methods to characterize living organisms. The topics covered include not only cellular motions but also temporal changes in metabolic components, protein levels, membrane potentials, cell types, and multicellular patterns, which are linked to functions such as cellular responses, adaptation, and morphogenesis. This book is intended for undergraduates, graduates, and researchers interested in theory and modeling in biology, in particular cell, developmental, and systems biology, also those in the fields of mathematics and physics who are interested in these topics.