Cell-to-cell communication (gap junctions, plasmodesmata) Original Scenario-Based Download PDF

Questions

1. 1.

   Deep within an exploratory bio-dome, synthetic biologists create a living biosensor consisting of two specialized cell layers: an outer layer of walled botanical cells that coordinates pressure signals, and an inner layer of flexible mammalian cells that propagates rapid electrical impulses. To establish cytoplasmic continuity, the outer tissue relies on plasma-membrane-lined tunnels traversing rigid barriers with an internal desmotubule, while the inner tissue utilizes clustered transmembrane protein complexes spanning intercellular space. When assessing how chemical messengers directly flow from cell to cell without crossing external fluid in these respective layers, which statement correctly compares these communication channels?

   • A) The outer layer relies on plasmodesmata, which maintain continuous plasma membranes and an endoplasmic reticulum extension across cell walls, whereas the inner layer relies on gap junctions composed of connexon protein rings that align without membrane fusion.
   • B) The outer layer relies on gap junctions that fuse the phospholipid bilayers of adjacent cells to form a shared cytoplasm, whereas the inner layer uses plasmodesmata made of clathrin proteins to pump molecules against their concentration gradient.
   • C) The outer layer uses plasmodesmata that completely seal the extracellular space to prevent fluid loss, whereas the inner layer uses gap junctions that transport large organelles and intact chromosomes via continuous microtubules.
   • D) The outer layer utilizes connexin channels embedded in the cellulose matrix to selectively export vesicle contents, whereas the inner layer utilizes plasmodesmata containing tight junction strands to regulate paracrine hormones.