Jeff Bradley, age 13, of Annapolis, Md., for his question:

WHAT IS BIOPHYSICS?

Biophysics is the science that uses the tools and methods of the physicist to study living things. Biophysics has been largely responsible for many discoveries about the physiology, or body functions, of humans and other organisms.

Biophysicists are interested in physical activities such as muscle movements, breathing and chewing. They study the effect of temperature, light, sound, pressure and other forces on living things. Osmosis is the biophysical activity of great importance in the physiology of living things.