Why was Chlamydomonas called unicellular?

It is called unicellular due to the fact that its body consists of one cell. She belongs to the kingdom of protists, that is, the simplest. This is their characteristic feature, as is the presence of heterotrophic nutrition and membrane organelles. All vital processes take place inside this one cell. Energy metabolism, gas exchange, excretion, reproduction, movement and many other processes are provided by various organelles, both membrane (nucleus, mitochondria, etc.) and non-membrane (cilia, flagella, ribosomes).