Signs of animals and unicellular organisms.

Animals have characteristic features, thanks to which a group of living organisms was singled out into a separate kingdom of living nature. The first sign is a heterotrophic type of nutrition. They are not able to synthesize organic substances, but can only eat ready-made substances. Also, they are able to move. Only a few species can lead an attached lifestyle.
Single-celled organisms are characterized by the fact that they consist of one cell. These can be protozoa, animals, plants, fungi and other kingdoms with the exception of viruses.