This book contains pedagogical introductions to a selection of the most exciting subjects in current biological physics: - Sorting DNA on a microchip: a first step towards miniature laboratories on a chip. - Modeling protein folding, structure, and motion. - Physics of organelles: mechanical characteristics of molecular motors; dynamics of microtubules; shapes of membranes, vesicles and cells. - A physicist's view of brains and neurons; statistics of sensory signal processing. - Evolutionary biology of molecules; pattern forming bacterial colonies; model ecologies with Darwinian co-evolution. The book is aimed at graduate students and researchers in physics, biology and mathematical modeling who have no prior knowledge of its subjects. Problems, methods, results, and perspectives are presented with the emphasis on general aspects and explanations, and only the necessary minimum of mathematical formalism is used.