Biology is the scientific study of life. It is a natural science with a
broad scope but has several unifying themes that tie it together as a single,
coherent field. For instance, all organisms are made up of cells that process
hereditary information encoded in genes, which can be transmitted to future
generations. Another major theme is evolution, which explains the unity and
diversity of life. Energy processing is also important to life as it allows
organisms to move, grow, and reproduce. Finally, all organisms are able to
regulate their own internal environments.
Biologists are able to study life at multiple levels of organization, from the
molecular biology of a cell to the anatomy and physiology of plants and
animals, and evolution of populations.