What is the name of the collection of bones that run down your back?

In addition to seeds, which of the following characteristics are unique to the seed-producing plants? a) sporopollenin b) lignin present in cell walls c) pollen d) use of air currents as a dispersal agent e) megaphylls

Why do we perceive objects as retaining their brightness under different lighting levels?

Organize the word parts according to where they appear in a medical term.