A prokaryote is a cell without a nucleus and eukaryotes are cells that contain nuclei. There's one quick test to distinguish prokaryotes from eukaryotes: if you can see a single organism, it's a eukaryote. All prokaryotes are single-celled organisms. Some eukaryotes are also single-celled organisms, but every multi-celled organism is eukaryotic. read more
Some of the advances seen in the evolution of eukaryotic organisms include linear, rather than circular, DNA and the development of numerous organelles within the cytoplasm of the cell. The linear DNA of eukaryotic cells is found primarily in the nucleus. read more