Describe the major differences between seedless vascular plants, gymnosperms, and angiosperms.

Question

What will be an ideal response?

Answer 1

Answer: Gymnosperms and angiosperms (seed plants) both produce seeds, which are specialized structures for protecting the developing sporophyte embryo from drying out and other dangers; this is something that seedless vascular plants do not have. Seed plants also produce gametophytes that develop within protective tissues in the sporophyte, which is something that does not happen in seedless vascular plants; instead, seedless vascular plants release gametophytes as single-celled spores that then must develop on their own. Seed plants also differ from seedless vascular plants in making pollen grains, which are specialized male gametophytes that are protected from drying out and that do not need external water to reach an egg. All of these adaptations allow seed plants to generally live in drier conditions than seedless vascular plants can handle. Within the seed plants, angiosperms differ significantly from gymnosperms in many ways. Angiosperms have enhanced xylem and phloem that provide more efficient transport of water and nutrients. Angiosperms have enhanced nutrition for embryos, with double fertilization that produces a unique triploid endosperm to nourish the embryo. They have flowers that often attract animal pollinators, thus providing more efficient means for pollination. Also, angiosperms have ovaries, which are tissues that shelter the ovule from desiccation and attack. Ovaries typically develop into fruits that can help protect seeds as well as aid in seed dispersal.