This is an introductory text on Biophysics meant for undergraduate students of our universities and technical institutions. The first part deals with organ systems and describes the principles of physics in the processes of locomotion, blood and fluid flow, respiration, audition and vision. The second part deals with cellular and molecular biophysics and covers, in depth, molecular forces and structure of bio molecules, dynamics of biomembranes, near-equilibrium thermodynamics, photosynthesis and cellular respiration, nerve excitation, etc.