What classification includes organisms like eukaryotic algae and protozoa?

The classification that includes organisms such as eukaryotic algae and protozoa is indeed the Kingdom Protista. This kingdom is characterized by a diverse group of mostly unicellular and simple multicellular organisms that do not fit into the traditional categories of plants, animals, or fungi.

Eukaryotic algae are plant-like protists that can perform photosynthesis due to their chloroplasts, while protozoa are primarily heterotrophic and often resemble small animals in their feeding habits. Both groups share the feature of having complex cell structures with a defined nucleus, which distinguishes them from prokaryotic organisms found in other kingdoms. Therefore, Kingdom Protista serves as a catch-all classification for these varied eukaryotic life forms.