What type of organisms are classified under the domain Eukarya?

Organisms classified under the domain Eukarya are characterized by having complex cellular structures that include a defined nucleus and membrane-bound organelles. This domain encompasses a diverse range of life forms including complex multicellular organisms like animals and plants, which exhibit higher levels of organization and specialization compared to simpler forms of life.

Additionally, Eukarya includes various unicellular organisms as well, such as protists, which can be quite complex. The key distinguishing feature of Eukarya is the presence of eukaryotic cells that have the capability to form multicellular structures, leading to diverse life forms that interact in various ecological systems. This broad classification captures the complexity of life found in animals, plants, fungi, and certain protists, setting it apart from other domains that contain primarily simpler or unicellular organisms.