Question

a researcher hypothesizes that water will move out of the cell more quickly when the concentration of salt in the water outside the cell is greater. which experiment would best test this hypothesis?
a researcher places cells from three different fish in the same concentration of salt water. then the researcher measures the size of each cell at the end of a 5 - minute period of time.
a researcher places three cells of the same type in varying concentrations of salt water. then the researcher measures the size of each cell every minute during a 5 - minute period of time.
a researcher places cells from three different fish in varying concentrations of salt water. then the researcher measures the size of each cell at the end of a 5 - minute period of time.
a researcher places three cells of the same type in the same concentration of salt water. then the researcher measures the size of each cell every minute during a 5 - minute period of time.

Explanation:

To test if water moves out of cells faster with higher external salt concentration, the experiment needs a constant cell type (to isolate variables) and varying salt concentrations (to test the hypothesis). Measuring size over time tracks water movement (cell shrinkage indicates water loss). The correct option controls cell type and varies salt concentration while monitoring changes continuously.

Answer:

A researcher places three cells of the same type in varying concentrations of salt water. Then the researcher measures the size of each cell every minute during a 5-minute period of time.