Which Structure or Compartment is Separate from the Apoplastic Transport

Question

Which structure or compartment is separate from the apoplastic transport route?
A) the lumen of a xylem vessel
B) the lumen of a sieve tube
C) the cell wall of a mesophyll cell
D) the cell wall of a root hair

Accepted Answer

The lumen of a sieve tube is part of the symplastic route, which involves transport within the cytoplasm of cells connected by plasmodesmata. The apoplastic route involves movement through the cell walls and intercellular spaces, excluding the cytoplasm and the lumina of xylem vessels or sieve tubes.