Solution concentration can be described in terms of tonicity. Solutions are hypertonic, isotonic, or hypotonic to cells. A hypertonic is one that has a greater concentration of solute outside the cell and therefore a lower concentration. Water will leave the cell, to the outside environment. This is one reason why organisms that live in fresh water cannot survive in salt water, the ocean. Water will leave the organism’s cells and eventually the cells will undergo plasmolysis and the organisms will die. An isotonic solution is a balanced solution. That is, the solution concentration is balanced with the solution inside the cell. Finally, when a cell is surrounded by a hypotonic solution, concentration of solute is greater inside the cell, concentration of water greater outside. Water moves into the cell and the cell swells. If enough water enters, the cell can burst.
On Day 2, the egg was placed in 10% salt water. Based on the student data, what type of solution would we label 10% salt water in this case?
A) hypertonic
B) hypotonic
C) isotonic
D) saline