The kelp life cycle involves a diploid sporophyte and haploid gametophyte stage. Between generations, the algae go through separate sporophyte (diploid) and gametophyte (haploid) phases. The condition of having separate sporophyte and gametophyte plants is called alternation of generations. The condition of having separate sporophyte and gametophyte plants is called alternation of the generations. The haploid gametophyte has "n" unpaired chromosomes, i.e. half the number of the sporophyte. The multicellular diploid sporophyte produces structures called spore capsules. The relationship between the sporophyte and gametophyte varies among different groups of plants. In heteromorphic algae, the morphology and size are different in the gametophyte and sporophyte. The fertilized zygote then grows into the mature diploid sporophyte. The zygote divides by mitotic division and grows into a multicellular, diploid sporophyte. Here the zygote divides repeatedly by mitosis and grows into a multicellular diploid sporophyte. The zygote divides by mitotic division and grows into a sporophyte that is diploid. The gametophytes remain attached to and part of the sporophyte. Two gametes fuse to form a zygote which develops into a new sporophyte. These spores are produced in sporangia that develop on the leaves of the fern's sporophyte.