Multicellular organism . All species of animals , land plants and most fungi are multicellular , as are many algae , whereas a few organisms are partially uni - and partially multicellular , like slime molds and social amoebae such as the genus Dictyostelium . A sporophyte ( [ spɔːrəʊˌfaɪt ] ) is the diploid multicellular stage in the life cycle of a plant or alga . All land plants , and most multicellular algae , have life cycles in which a multicellular diploid sporophyte phase alternates with a multicellular haploid gametophyte phase .
Multicellular organisms include land plants.