Final answer:
A cell that has burst open is described as having undergone lysis, which can happen due to osmotic disruption causing the cell to absorb too much water until the plasma membrane breaks.
Step-by-step explanation:
The word that describes a cell that has burst open is lyse or lysis. This often occurs when a cell, such as a red blood cell, swells beyond what the plasma membrane can tolerate. The reason for this swelling is often due to osmotic disruption, where water moves into the cell by osmosis from an area with fewer solutes to an area with more solutes. When the cell takes in too much water, it can no longer maintain its integrity, leading to the plasma membrane tearing apart and ultimately causing the cell to burst. Additionally, certain processes in the immune system, like the complement system involving C5 to C9, can create complexes that induce holes in the plasma membrane of an invader, causing it to swell and burst.