Once food has reached the sea floor, currents carry this food and organisms filter it without having to use their own energy to go and get food. Another way organisms use energy is by coming out at night and rising to feed on upper-level organisms.
Physical Science redirects here. It is not to be confused with Physics. Physical science is a branch of natural science that studies non-living systems, in contrast to life science. It in turn has many branches, each referred to as a physical science, together called the physical sciences.
Among the undergraduate courses that are useful when a student applies to a physical therapy education program are anatomy, biology, chemistry, social science, mathematics and physics. Before granting admission, many programs require volunteer experience in physical therapy departments of hospitals or clinics. Specific course prerequisites vary for each school, but the following courses will fulfill all that are generally required.