A) They contain cytoplasm at maturity.
B) They have both primary and secondary walls.
C) They have only secondary walls made of lignin.
D) They have only primary walls made of cellulose.
E) All of these answers apply.

A) Only fossilized plants exhibit this habit.
B) The ancestors of land plants, green algae, lack the structural support to stand erect in air.
C) At the time of the first land plants, the atmosphere had oxygen mainly close to the ground.
D) Land animals of that period consumed erect plants.
E) Land animals of that period were small, so they needed short plants to eat.

A) cuticle and pores
B) roots and true leaves
C) roots and vascular tissue
D) tracheids and vessel elements
E) All of these answers apply.