Final answer:
Spikes on a blood cell are caused by a hypertonic solution, as water leaves the cell due to osmotic pressure, leading to the cell's collapse and a spiked appearance.
Step-by-step explanation:
The type of solution that causes "spikes" to form on a blood cell is a hypertonic solution. When red blood cells are placed in a hypertonic solution, water flows out of the cells and into the surrounding solution due to osmotic pressure. This causes the cells to shrink and take on a spiked, shriveled appearance as they collapse. This is in contrast to an isotonic solution, where the red blood cell retains its normal shape, and a hypotonic solution, where the cell swells and may even burst from an excess influx of water.
It is critical that intravenous (IV) solutions be isotonic with blood serum to avoid these deleterious effects on red blood cells.