each student in a biology laboratory received two solutions. one solution was distilled water. the other was a salt solution with concentrations of salts slightly greater than that of a living cell. the solutions were labeled x and y, respectively. the students were instructed to place some fresh-water protozoans in each of the solutions and to identify the solutions on the basis of their observations. the protozoans in solution x shriveled. those in solution y swelled up and burst.
