KingdomProtista

Eukaryotes are considerably more complicated than prokaryotes (KingdomMonera).

Each cell has at least one nucleus, a structure where the DNA is stored bound by a double membrane. Generally there is more than one ChromoSome, and there are usually multiple copies of the same genes. Nuclei divide through a process called NuclearMitosis, where microtubules pull apart the divided chromosomes and ensure each daughter has a full set.

Many eukaryotes also undergo a process of SexualReproduction. This involves two phases: SynGamy, where two haploid (single gene set) cells fuse to form a diploid, and NuclearMeiosis, a process similar to mitosis where the chromosomes are divided to form haploids. The role of haploid and diploid stages in the life cycle varies considerably.

There are a wide variety of intracellular organelles. These include membrane bound structures, notably EndoplasmicReticulum and various-purposed vacuoles. Nearly all eukaryotes have MitoChondria to burn food, and quite a few have ChloroPlasts for photosynthesis; these appear to actually be reduced endosymbiont bacteria.

Multicellular organization has arisen among the eukaryotes a number of times. Of such forms, the KingdomAnimalia, KingdomPlantae, and KingdomFungi are typically listed separately as top-level taxa. Other groups are left in the junk-basket category of KingdomProtista. These include the following:

• TaxonEuglenozoa (euglenids, kinetoplastids)
• TaxonAlveolata (ciliates, dinoflagellates, apicomplexan sporozoa)
• TaxonChromista (stramenopiles: water molds, golden and brown algae, diatoms)
• FlagellateTaxa
• AmoeboidTaxa
• AlgalTaxa
• SlimeMolds