Which organelle forms the surface of a cell, separating its contents from the outside world

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

Biology ! the conversion of inorganic carbon to organic carbon by plants during photosynthesis is known as _[blank]_. filtration immigration reabsorption primary production

Which statement describes compounds a. compounds are made of one type of atom. b. compounds cannot be represented by models. c. compounds are represented by chemical formulas. d. compounds cannot be broken down into simpler forms.