Red blood cells will burst when placed in freshwater due to osmosis. Freshwater is hypotonic compared to the inside of the cells, which causes water to flow into the cells. Since red blood cells lack a rigid cell wall, they cannot withstand the increased internal pressure, leading to lysis (bursting).
In contrast, plant cells have a rigid cell wall that provides structural support. When placed in freshwater, water also enters plant cells, but instead of bursting, the internal pressure increases, creating turgor pressure. This turgor pressure helps maintain the cell's shape and prevents bursting, allowing plant cells to remain intact even in hypotonic environments.