A eukaryote is an organism whose cells contain a nucleus and other organelles, all enclosed in a membrane. There are two types of division processes for this cell: mitosis and meiosis. The domain Eukaryota seems to be monophyletic, which makes up one of the three domains of life. These types of cells began developing around 1.6-2.1 billion years ago. The internal membrane of a Eukaryote is made up of the endomembrane system, which contains membrane bound structures. The mitochondria of the cell are surrounded by 2 phospholipid bilayers, the inner one called cristae. Many eukaryotes have long cytoplasmic motor projections, such as flagella or cilia. Animal and plant cells are very similar to one another, the only difference between the two is the animal cell’s lack of a cell wall and chloroplasts.