Talk about digenetic life cycle of algae *isomorphic*

All Ulva species alternate between gametophytic and sporophytic life stages (haplodiplontic life cycle n/2n) with similar morphologies (isomorphic generation). The gametophytes are haploid and the sporophytes are diploid. Both gametes (biflagellated) are motile (zoogamy, planogamy) and the female gamete is larger than the male (anisogamous). The gametes fuse to produce a quadriflagellate zygote. The zygote swims for a short time then comes to rest, withdraws its flagella and grows into a new sporophyte. The mature sporophyte forms sporangia and produces by meiosis haploid quadriflagellate zoospores. Zoospores withdraw their flagella and develop into gametophytes.