AP BIO - Cell Transport & Osmosis Exam Review

Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 0.15 M salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are:

• hypotonic to both fresh water and the salt solution

• hypertonic to both fresh water and the salt solution

• hypertonic to fresh water but hypotonic to the salt solution

• hypotonic to fresh water but hypertonic to the salt solution

• isotonic with fresh water but hypotonic to the salt solution

Tags

NGSS.HS-LS1-3

Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?

• Water will leave the cells, causing them to shrivel and collapse.

• NaCl will be exported from the red blood cells by facilitated diffusion.

• The blood cells will take up water, swell, and eventually burst.

• NaCl will passively diffuse into the red blood cells.

• The blood cells will expend ATP for active transport of NaCl into the cytoplasm.

Tags

NGSS.HS-LS1-3

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane which is permeable to sodium chloride and water but not to glucose. At the beginning of the experiment:

• side A is hypertonic to side B.

• side A is hypotonic to side B.

• side A is isotonic to side B.

• side A is hypertonic to side B with respect to glucose.

• side A is hypotonic to side B with respect to sodium chloride.

The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane which is permeable to sodium chloride and water but not to glucose. If you examine side A after three days, you will find:

• a decrease in the concentration of NaCl and glucose and an increase in the water level.

• a decrease in the concentration of NaCl, an increase in water level, and no change in the concentration of glucose.

• no net change in the system.

• a decrease in the concentration of NaCl and a decrease in the water level.

• no change in the concentration of NaCl and glucose and an increase in the water level.

A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water–equal to the volume of blood lost–is transferred directly into one of his veins. What will be the most probable result of this transfusion?

• It will have no unfavorable effect as long as the water is free of viruses and bacteria.

• The patient's red blood cells will shrivel up because the blood fluid has become hypotonic compared to the cells.

• The patient's red blood cells will swell because the blood fluid has become hypotonic compared to the cells.

• The patient's red blood cells will shrivel up because the blood fluid has become hypertonic compared to the cells.

• The patient's red blood cells will burst because the blood fluid has become hypertonic compared to the cells.

A protein pump lowers the pH of a cell's cytosol by pushing H+ ions into the cell against their concentration gradient. Based on the figure to the right, which of these experimental treatments would increase the rate of sucrose transport into the cell?

• decreasing extracellular sucrose concentration

• decreasing extracellular pH by allowing more H+ to leave the cell

• decreasing cytoplasmic pH by pumping more H+ ions into the cell

• adding an inhibitor that blocks the regeneration of ATP

• adding a substance that makes the membrane more permeable to hydrogen ions

The sucrose-H+ cotransporter is considered a symporter due to its role of transporting both sucrose and H+ ions in the same direction. Which of the following statements best explains what powers this form of active transport?

• The hydrolysis of ATP by the Sucrose-H+ cotransporter pumps sucrose against its concentration gradient.

• Sucrose flows through the cotransporter via facilitated diffusion.

• The sucrose is pushed through the cotransporter by the water potential outside the cell.

• The cotransporter harnesses energy from allowing H+ ions to flow down their electrochemical gradient.

Five dialysis bags, constructed from a semi-permeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.

Which line represents the bag that contained a solution isotonic to the 0.6 molar solution at the beginning of the experiment?

• A

• B

• C

• D

• E

Tags

NGSS.HS-PS1-5

Five dialysis bags, constructed from a semi-permeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.

Which lines represent the bag that contained a solution hypertonic to the 0.6 molar solution at the beginning of the experiment?

• A

• B

• C

• D

• E

Tags

NGSS.HS-PS1-5

Five dialysis bags, constructed from a semi-permeable membrane that is impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.

Which lines represent the bag that contained a solution hypotonic to the 0.6 molar solution at the beginning of the experiment?

• A

• B

• C

• D

• E

Tags

NGSS.HS-PS1-5