Question

graph 1 title
% change in mass (%)
select all points

1. make a claim about the water potential of the potato. provide evidence and reasoning to support your claim.

claim

• the water potential of the potato is equal to the 0.2 m nacl solution.

evidence
b
reasoning

• a 0.2 m nacl solution is hypertonic with the potato cells.
• a 0.2 m nacl solution is isotonic with the potato cells.
• a 0.2 m nacl solution is hypotonic with the potato cells.

Explanation:

1. Claim: The water potential of the Potato is equal to the 0.2 M NaCl solution.
2. Evidence: From the graph, the linear fit line for % change in mass crosses 0% at a NaCl concentration of 0.2 M. A 0% change in mass means no net movement of water into or out of the potato cells.
3. Reasoning: Water moves across a semipermeable membrane from an area of higher water potential to lower water potential. No net water movement occurs when the water potential of the potato cells is equal to the water potential of the surrounding solution, so the potato cells and 0.2 M NaCl solution have equal water potential.

Answer:

• Claim: The water potential of the Potato is equal to the 0.2 M NaCl solution.
• Evidence: The linear fit line on the graph shows 0% change in potato mass at 0.2 M NaCl.
• Reasoning: A 0.2 M NaCl solution is isotonic with the Potato cells.