Which kingdom includes all animals and is characterized by heterotrophic eukaryotes?

The kingdom that includes all animals and is characterized by heterotrophic eukaryotes is indeed Kingdom Animalia. Members of this kingdom are defined by their inability to produce their own food, which means they rely on other organisms for nourishment—this is what makes them heterotrophic. They also possess complex, multicellular structures that allow for specialized functions and systems, distinguishing them from simpler life forms.

Kingdom Animalia encompasses a vast diversity of organisms, ranging from simple sponges to complex mammals, all sharing these fundamental characteristics of being multicellular eukaryotes that consume organic material. The organism's structure is organized into tissues and organs, allowing for more advanced functions and interactions with their environment.

In contrast, other kingdoms mentioned do not encompass animals: Kingdom Protista primarily consists of unicellular organisms or simple multicellular organisms, Kingdom Fungi includes organisms that absorb nutrients from decomposing organic matter, and Kingdom Plantae consists of autotrophic eukaryotes that produce their own food through photosynthesis. This distinction is crucial in understanding the classification of living organisms and their nutritional modes.