Chlamydomonas is a member of protista.. In earlier classification schemes it was placed under plantae in sub category algae along with chlorella and the sole reason of it would be presence of cell wall in both. read more
On the basis of characters Chlamydomonas resemble to kingdom protista as well as kingdom plant but on the basis of phylogeny or evolutionary study Chlamydomonas related to kingdom plant not to kingdom protista. On molecular level Chlamydomonas resemble kingom plant. read more
Actually, Chlamydomonas is currently considered to be a protist. The division to which it belongs, the Chlorophyta, has been reclassified under the kingdom Protista following recent biochemical studies. read more
Recently there was a controversy weather they are the part of kingdom algae or kingdom Protista . The one who proposed that they are part of kingdom Protista claimed it on the basis of its level of organisation (that is unicellular). read more