What is Chlorella (green algae) like?

Chlorella vulgaris is a common unicellular green algae in Chlorella genus of Chlorophyta. It is a spherical unicellular freshwater algae with a diameter of 3 ~ 8 microns. It is one of the earliest life on earth. It appeared more than 2 billion years ago, and its genes have never changed. It is an efficient photosynthetic plant, which grows and reproduces by photosynthesis and is widely distributed.