Eukaryotic cells are defined by having organelles which contain individual membranes that carry out specialized functions. This varies from a prokaryotic cell where the components within the cell float freely within one membrane. The advanced structure of a eukaryote allows a greater diversity of organisms with cells, tissue and organ systems specialized to carry out specific functions. The defining feature a eukaryote has which a prokaryote lacks is the nucleus, sometimes referred to as the nuclear envelope. This organelle serves to produce and distribute genetic material throughout and organism.
Kingdoms that contain eukaryotic cell structures include fungi, plantae and animalia. Despite being more complex by nature, there are still some unicellular organisms which are classified in the eukaryotic taxonomy. Contrary to popular belief, prokaryotes are far more common then eukaryotes when it comes to individual organisms. Many eukaryotes in fact have prokaryotes which make up the organisms structure however since a eukaryotic organism is vastly more complex, when thinking individual cells the biomass variation between prokaryotes and eukaryotes are fairly equal.
A eukaryotic cell is normally much larger than its prokaryote counterpart and the materials contained within the cells such as ribosomes are generally larger in size as well. Simple membranes called vesicles or vacuoles are formed by splitting off from other membrane materials to bind organelles in a more secured structure within the cell. The endoplasmic reticulum (ER) is responsible for transferring materials generated in the nucleus to other parts of the cell for further use and distribution.
Mitochondria are another key component which almost all eukaryotes contain. It has two membranes of phospholipid bi-layers which encase the organelle and its DNA. Mitochondria are believed to have been derived from endosymbionts which are organisms that live in other organisms or cells. Contained within mitochondria are its own DNA and similar versions can be found in plastids in plant life.
Eukaryotic reproduction is done through the cell division processes known as meiosis or mitosis. The nucleus effectively separates two duplicate chromosomes by using microtubules to move them within the cell before division occurs. Mitosis is the process from which a cell splits its self into two identical clones, like the process of skin cells replacing themselves in humans. Meiosis is the division process that is required in sexual reproduction where a diploid (two chromosome cell) from each parent combines the chromosomal sequence to pass on genetic materials.