Which group of eukaryotes consists of single-celled organisms?

The choice of Protists as the correct answer is based on the defining characteristic of this group within the domain of eukaryotes. Protists are primarily known for being a diverse group that includes many single-celled organisms, such as amoebas, paramecia, and various algae. This group is essentially a catch-all category for eukaryotes that do not fit neatly into the other kingdoms, and it encompasses a wide range of life forms that can be unicellular or multicellular.

In contrast, the other groups—Fungi, Animalia, and Plantae—are predominantly multicellular organisms. While there are unicellular fungi, such as yeast, they do not represent the majority of the Fungi kingdom. In the Animalia kingdom, the vast majority of members are multicellular organisms, including all the animals familiar to us. Plantae primarily consists of multicellular plants, although some simple plant-like organisms such as certain algae may be unicellular, they are not classified under this kingdom to the same extent as protists.

Thus, identifying Protists as the group primarily composed of single-celled organisms affirms their unique position in the eukaryotic lineage. This distinction is crucial in understanding the diversity of life forms and their