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.
National Science Education Standards. The National Science Education Standards (NSES) are guidelines for K-12 science education in United States schools. They were established by the National Research Council in 1996 to provide a set of goals for teachers to set for their students and for administrators to provide professional development. The NSES have significnatly influenced various states' own science learning standards and state-wide standardized testing.