G0 is best understood as a pause button on the cell cycle rather than a dead end, and the four options are really testing whether you know that the pause can be reversed.
- Neither proliferate nor metabolically active: Cells resting in G0 are still alive and carrying out normal cell functions such as protein synthesis, so calling them metabolically inactive is wrong.
- Metabolically inactive but no longer proliferate: This gets the not proliferating part right but wrongly assumes the cell has shut down metabolically, which contradicts how G0 cells actually behave.
- Can proliferate if metabolism called on to do so: Cells in G0, like liver cells or lymphocytes, stay metabolically active and can be pulled back into the active cycle when the right growth signal arrives, letting them proliferate again.
- Cannot proliferate even metabolism called on to do so: This denies the reversibility of G0 altogether, treating the resting stage as permanent, which is not how the cell cycle actually works for most G0 cells.
Since G0 cells keep their metabolic machinery running and are capable of re-entering the cycle when triggered, the correct description is that they can proliferate if called on to.
Let's summarize:
- G0: a quiescent, reversible pause, not a metabolic shutdown.
- Cells stay active and can resume division on the right signal.
- This rules out both permanently non dividing options.
So the correct description is that G0 cells can proliferate if their metabolism is called on to do so.