3. What forms the "rungs" of the ladder? How many are there? What are their names?

Which of the following is most important in making the typical seed more resistant to adverse conditions than the typical spore? a) a different type of sporopollenin b) an internal reservoir of liquid water c) integument(s) d) ability to be dispersed e) waxy cuticle

List charasteristics of athenosphere

Explain the significance of thesaurus geographicus