Organisms with cells possessing a membrane-bounded nucleus in which the DNA is complexed with histones and organized into chromosomes. Eukaryotic cells also have an extensive cytoskeleton of protein filaments and tubules, and many cellular functions are sequestered in membrane-bounded organelles such as mitochondria, chloroplasts, endoplasmic reticulum and Golgi apparatus. The eukaryotes comprise protozoans, algae, fungi, slime moulds, plants and animals. cf. prokaryotes.