Prokaryotic refers to organisms that lack a cell nucleus and membrane-bound organelles. The antonym of prokaryotic is eukaryotic, which are organisms that possess a distinct nucleus and other membrane-bound organelles like mitochondria, chloroplasts, and endoplasmic reticulum. Eukaryotes include animals, plants, fungi, and protists. Unlike prokaryotes, eukaryotes have a more complex cellular structure and are usually larger in size. They reproduce sexually and asexually, and possess linear chromosomes that are enclosed within the nucleus. Eukaryotic cells also have a cytoskeleton that gives them support, shape, and the ability to move.