[Campbell Biology P.169] While gap junctions in animal cells are functionally similar to pla... | Practice Question

While gap junctions in animal cells are functionally similar to plasmodesmata in plants, they differ structurally. What is a key structural distinction between gap junctions and plasmodesmata as described in the text?

  • A: Gap junctions allow passage of large macromolecules, while plasmodesmata only allow small molecules.
  • B: Gap junction pores are not lined with membrane, whereas plasmodesmata channels are.
  • C: Gap junctions are formed by membrane proteins, while plasmodesmata are formed by the extracellular matrix.
  • D: Gap junctions are only found in epithelial tissue, while plasmodesmata are found throughout the plant.

Explanation

The text explicitly states: ' Gap junctions are most like the plasmodesmata of plants, although gap junction pores are not lined with membrane—rather, they consist of proteins extending from each cell's membrane that form a connecting pore. '