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.
Science and math classes Take science and math classes in high school. It is great if you can take AP science classes. Take as many science classes as you can, especially chemistry, biology, physics, and even prepare in math. These are classes you need to do well in because they count as part of your science GPA.