Complex sentence: In some multicellular green algae ("Ulva lactuca" is one example), red algae and brown algae sporophytes and gametophytes may be externally indistinguishable isogamous, all of one size, shape and general morphology.
Split into simpler sentences: In some multicellular green algae ("Ulva lactuca " is one example), red algae and brown algae sporophytes and gametophytes may be externally indistinguishable (isomorphic). In"Ulva" the gametes are isogamous, all of one size, shape and general morphology.