Practice question

Seed habit evolution confers multiple adaptive advantages over free spores: embryo protected within integumented seed coat, dormancy allows dispersal temporally and spatially avoiding stress, nutrient reserves support autonomous seedling establishment, reduction of gametophyte limits resource investment compared to massive gametophyte dependent forms. Dependence on external water for fertilization using flagellate antherozoids swimming characterizes pteridophytes and bryophytes, eliminated by evolution of siphonogamy and pollen tube in seed plants. Therefore describing dependence on water as seed advantage contradicts gymnosperm and angiosperm adaptation to terrestrial land environments.