Why are protists, plants, fungi, and animals classified into the same domain but into different kingdoms ?

Archaea and Eubacteria are both prokaryotes. They can be separated mainly by their habitats. Why are protists, plants, fungi, and animals classifies into the same domain but into different kingdoms? They are the same domain because they are all Eukaryotes.

They are the same domain because they are all Eukaryotes. They are different from each other because they are not all Multicellular.

label a cell membrane

label b cytoplasm

label c ribosomes

label d dna

the membrane forms the outside of the cell

cytoplasm is the liquid within

ribosomes are the components within that distribute rna

the dna is the genetic make-up