What are the signs of unicellular animals?

Single-celled animals are a misnomer. They must be called protozoa or protists. This is a separate kingdom of living nature. The protist organism consists of one cell. They have a heterotrophic diet. Some protozoa are also capable of autotrophic nutrition (euglena green). Another characteristic feature of protists is that they are capable of movement in search of food, sexual partners and to avoid dangers. But unlike bacteria, protists have membrane organelles in their structure.