How does a hypotonic solution affect a red blood cell? How does it affect a gram positive bacterial cell?

Exposure of a red blood cell to a hypotonic solution causes swelling and eventual bursting of the cell membrane upon prolonged exposure.

Exposure of a gram positive bacterial cell causes the flow of water into the cell however, its rigid cell wall protects it from bursting.

Explanation:

A red blood cell has a cell membrane but no rigid cell wall. The inside of a red blood cell is hypertonic (contains more solutes like DNA, proteins) therefore, an exposure to a hypotonic solution (solution with less solutes and more water), causes water to flow into the cell membrane by osmosis.

Osmosis is the movement of fluids from a region of higher concentration to a region of lower concentration. This creates a balance in fluid contents across both environments.

After prolonged exposure to the hypotonic solution, the flexible cell membrane swells and eventually bursts.

A gram positive bacterial cell has a rigid cell wall and a cell membrane. When exposed to a hypotonic solution, water flows from the outside environment to the interior of the cell by osmosis through the cell wall and membrane. The rigid cell wall of the bacterial cell however, contains the swelling and prevents the cell from bursting.