Both gametophyte and sporophytes are unicellular in

In unicellular green algae, the gametophyte which is vegetative cell and gametes are unicellular and the sporophyte (zygote or zygospore) is also unicellular. In Funaria and Dictyota both gametophyte and sporophytes are multicellular. In Volvox, the gametophyte is multicellular and coenobium but the sporophyte (zygote or zygospore) is unicellular.