How does osmosis affect the cells?

Osmosis has a direct impact on cells but it may affect cells differently depending on the type of cell and the type of osmosis that occurs. 

An animal cell, which has a relatively thin cell wall, will lyse when placed in a hypotonic solution. The solution within the cell has a lower concentration of water than the hypotonic solution, hence water flows into the cell to achieve equilibrium. The excess water in the cell causes dissolution of the cells by lysis. 

On the other hand, a hypotonic solution is ideal for a plant cell, which has a thicker, more rigid cell wall and requires more water. A plant cell will maintain its structure and will not lyse when placed in a hypotonic solution. 

However, when placed in an isotonic solution, an animal cell will find equilibrium and survive while a plant cell will lose its turgidity, resulting in drooping of the leaves.