All modern organisms fall into two classes, eukaryotes and prokaryotes. Eukaryotes (from the Greek meaning "true kernel") have a cell nucleus that harbors most of the cell's genetic information and includes organisms such as humans, plants and fungi. In prokaryotes, the cell's contents, including its genetic material, are diffusely distributed. Eukaryotes typically have much larger genomes, which is generally thought to relate to their greater complexity. Prokaryotes, however, not to be outclassed, comprise the bulk of Earth's biomass. Generally speaking, prokaryotes seem to approach the process of living by making copies of themselves as quickly as they can, while eukaryotes survive by being highly specialized at making copies of themselves in particular ways.
