Final answer:
There are two types of cells that reside in G0: those that enter G0 temporarily until an external signal triggers G1, and those that never or rarely divide and remain in G0 permanently.
Step-by-step explanation:
The two types of cells that reside in G0 are:
- Cells that enter G0 temporarily until an external signal triggers the onset of G1.
- Cells that never or rarely divide, such as mature cardiac muscle and nerve cells, remain in G0 permanently.
Cells in G0 are in a quiescent (inactive) stage that occurs when cells exit the cell cycle. Some cells enter G0 temporarily due to environmental conditions or growth factors, while others remain in G0 permanently. This phase allows cells to rest and perform their specific functions without preparing for division.