1. What new, important trait do all gymnosperms and angiosperms share, that is lacking in ferns and horsetails?
2. Which group evolved first, Gymnosperms or Angiosperms? Which is most numerous (rich in species) now? 
3. Which group (Gymno or Angio) was dominant in the Cenozoic era? The Mesozoic era? The Paleozoic era? (fig 29.1)
4a. Which gymnosperm group is represented by the most living species? 
4b. Which by only one?
4c. Which is mainly tropical?
4d. Which two groups develop their seeds in cones, which are often large?
5. Are flowers associated with "naked seeds" or "enclosed seeds"?
6. Gymnosperms lack flowers; then how do they get fertilized to make seeds?
7. What is the micropyle?
8. Which of the following plant clades makes the most use of animal (especially insect) pollinators for fertilization? How do the other clades accomplish fertilization?
Gymnosperms, Mosses, Ferns, Angiosperms
9. What happens during "double fertilization"? Which plant groups do it?
10. How is triploid endosperm formed, and what is its function?
11. What are the three stages of activity in the life of an angiosperm pollen grain which succeeds in fertilizing an ovule with its sperm? 
12. What happens in the grain stage, the tube stage, and the sperm stage?