The Biological Effects of Tonicity

The video explains tonicity, which is the ability of external solutions to change the water content inside cells. It covers three types of solutions: hypotonic, isotonic, and hypertonic. Hypotonic solutions cause cells to swell, isotonic solutions maintain equilibrium, and hypertonic solutions lead to cell shrinkage. The effects on both red blood cells and plant cells are discussed, highlighting the role of osmosis in these processes.

What happens to a red blood cell when placed in a hypotonic solution?

• It expands and bursts.

• It becomes rigid.

• It remains unchanged.

• It shrivels up.

How do plant cells avoid bursting in a hypotonic environment?

• By increasing solute concentration inside.

• Through their strong cell walls.

• By shrinking their vacuoles.

• By losing water rapidly.

In an isotonic solution, what happens to the water movement across the cell membrane?

• Water moves only out of the cell.

• Water movement stops completely.

• Water moves only into the cell.

• Water moves in and out at the same rate.

What is the solute concentration of an isotonic saline solution compared to blood plasma?

• Varies with temperature.

• Equal to blood plasma.

• Lower than blood plasma.

• Higher than blood plasma.

What effect does a hypertonic solution have on plant cells?

• It causes them to burst.

• It makes them swell.

• It leads to wilting.

• It has no effect.