Understand the three domains of life: Bacteria, Archaea, and Eukarya. These domains classify all living organisms based on cellular structure and genetics.
Recall that fungi are organisms with complex cellular structures, including membrane-bound organelles such as a nucleus.
Recognize that organisms with a true nucleus and membrane-bound organelles belong to the domain Eukarya.
Note that Bacteria and Archaea are prokaryotes, meaning they lack a nucleus, which excludes fungi from these domains.
Conclude that since fungi have eukaryotic cells, they belong to the domain Eukarya.