Refer to the graph below. The graph shows results from an investigation using living cartilage cells extracted from slaughtered cows.The cells were treated so that they took up a fluorescent dye in their cytosols without losing viability.(This dye undergoes a change in fluorescence intensity upon binding calcium ions.) The treated cells were then exposed to forces that mimic the forces on cartilage during weight-bearing exercise.This experiment was then repeated with cells that were pretreated with a calcium ion channel inhibitor before exposure to forces of weight-bearing exercise.This inhibitor is specific for intracellular calcium ion channels.Which statement is consistent with the results shown in the graph?
A) Calcium ions move out of the cytosol into other cell compartments in response to a mechanical stimulus.
B) Calcium ions are inhibited from moving out of the cytosol into other cell compartments as the result of a mechanical stimulus.
C) A mechanical stimulus induces cellular changes in cartilage that include the opening of intracellular calcium ion channels.
D) Extracellular calcium ion channels open as part of the response of cartilage cells to a mechanical stimulus.
E) Cartilage cells use an inhibitor molecule to prevent intracellular calcium ion release during weight-bearing exercise.

Question

Refer to the graph below.  The graph shows results from an investigation using living cartilage cells extracted from slaughtered cows.The cells were treated so that they took up a fluorescent dye in their cytosols without losing viability.(This dye undergoes a change in fluorescence intensity upon binding calcium ions.) The treated cells were then exposed to forces that mimic the forces on cartilage during weight-bearing exercise.This experiment was then repeated with cells that were pretreated with a calcium ion channel inhibitor before exposure to forces of weight-bearing exercise.This inhibitor is specific for intracellular calcium ion channels.Which statement is consistent with the results shown in the graph?
A) Calcium ions move out of the cytosol into other cell compartments in response to a mechanical stimulus. 
B) Calcium ions are inhibited from moving out of the cytosol into other cell compartments as the result of a mechanical stimulus. 
C) A mechanical stimulus induces cellular changes in cartilage that include the opening of intracellular calcium ion channels. 
D) Extracellular calcium ion channels open as part of the response of cartilage cells to a mechanical stimulus. 
E) Cartilage cells use an inhibitor molecule to prevent intracellular calcium ion release during weight-bearing exercise.

Quizplus · Accepted Answer

The graph shows an increase in fluorescence intensity upon exposure to weight-bearing exercise in the control group (untreated cells) but not in the group pretreated with a calcium ion channel inhibitor. This suggests that a mechanical stimulus induces the opening of intracellular calcium ion channels, leading to an increase in cytosolic calcium ions and a change in fluorescence intensity. Option A and B are incorrect because the graph shows an increase in fluorescence intensity, indicating an increase in cytosolic calcium ions, not a decrease or movement to other compartments of the cell. Option D is incorrect because the inhibitor used is specific for intracellular calcium ion channels, not extracellular ones. Option E is also incorrect because the inhibitor is used to block intracellular calcium ion channels, not prevent the release of calcium ions.

Refer to the Graph Below