1. Follow the apparent evolution of the different kinds of land plants, pointing out how each step is an adaptation to the land and how the plants might have moved in stages from green algae to plants living on dry land.
2. Discuss why the seed plants have a reproductive advantage over plants that reproduce by releasing spores, with emphasis on the multicellular embryo, stored food, and seed coat as opposed to the single cell of the spore.
3. Discuss the effects of the development of pollen
on the evolutionary success of the seed plants, with emphasis
on the advantage gained in having animals disperse pollen rather
than the wind. Discuss the allergies many people have to pollen
and how much energy must go into producing this pollen.