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.
Free Life Sciences Activities for Different Grades. Life science is a vast subject and there is something new to learn at each grade. It is a subject that introduces kids to a wide range of concepts including genetics, cell biology, viruses and bacteria, organisms, ecology, energy, survival and much more. As kids move from one grade to the other, they are introduced to more complex life science concepts.