Aliermation of generations is a type of life cycle characteristic of plants and a few algae and fungi in which they spend part of their life in a multicellular ' \(n\) ' gametophyte stage (sexual stage) and part in a multicellular ' \(2 n\) ' sporophyte.(asexual) stage. The gametophyte develops from a spore and produces gametes; the sporophyte develops from a zygote and produces spores. In ferns the sporophyte is reduced to a prothallus.