Ans.
According to early classification system, both protists and animals were grouped under same kingdom as they both are eukaryotic and mostly heterotrophic organisms.
This classification was not accurate as protists do not share all caharcteristics with animals. Animals are multicellular organisms, but not all protists are multicellular as they can be either multicellular or unicellular. Many protists possess cell walls, while animal cells do not have cell walls. Some of the protists are autotrophs that can make their food, while all animals are heterotrophs.
Thus, the early classification, in which protists and animals were placed in a single kingdom was not accurate.
