Question

samples of blood were mixed with different sodium - chloride solutions. in one concentration of sodium chloride, the red blood cells were maintain their normal shape. in another concentration of sodium chloride, the red blood cells were observed to swell and burst. the cells maintained their normal shape were in a state of homeostasis. which process best explains what happened to the red blood cells which swelled and burst and why?
a. salt diffused into the red blood cells and the higher concentration of salt caused the red blood cells to burst.
b. water diffused into the red blood cells by osmosis, and the higher concentration of water caused the red blood cells to burst.
c. salt was taken into the red blood cells by passive transport, and the higher concentration of salt caused the red blood cells to burst.
d. water was taken into the red blood cells by active transport, and the higher concentration of water caused the red blood cells to burst.

Explanation:

Osmosis is the movement of water across a semi - permeable membrane from an area of lower solute concentration to an area of higher solute concentration. In this case, water diffused into the red blood cells (from a lower solute - higher water concentration outside to a higher solute - lower water concentration inside), causing them to swell and burst. Salt does not diffuse into the cells in a way that would cause bursting as described in the incorrect options, and water movement in this context is by osmosis (passive) not active transport.

Answer:

B. Water diffused into the red blood cells by osmosis, and the higher concentration of water caused the red blood cells to burst.