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A student investigated the movement of water in potatoes - Edexcel - GCSE Biology Combined Science - Question 5 - 2023 - Paper 1
Question 5
A student investigated the movement of water in potatoes. The student used three identical cubes of potato. The size of a cube is shown in Figure 6. Calculate the v... show full transcript
Worked Solution & Example Answer:A student investigated the movement of water in potatoes - Edexcel - GCSE Biology Combined Science - Question 5 - 2023 - Paper 1
Step 1
Step 2
Give one way the student could ensure the measurement of the mass of the cube is accurate.
Answer
To ensure the measurement of mass is accurate, the student could use a calibrated balance or scale that is sensitive enough to detect small changes in mass. Additionally, the mass should be measured at the same temperature to avoid variations that might affect the readings.
Step 3
Explain the mass change in the cube in the concentrated salt solution.
Answer
In the concentrated salt solution, the mass change can be explained by osmosis. Water moves from an area of lower solute concentration (inside the potato cube) to an area of higher solute concentration (the concentrated salt solution) to equalize solute concentrations on both sides of the cell membrane. This causes the potato cube to lose water, and thus its mass decreases.
Step 4
Describe how the student could modify this investigation to find this concentration.
Answer
The student could conduct a series of experiments using different concentrations of salt solution and measure the mass change of the potato cubes after each trial. By identifying the concentration at which the mass of the potato cube remains constant, the student can determine the concentration where the potato cells neither gain nor lose mass.
Step 5
Explain why potato cells do not burst when placed in water.
Answer
Potato cells do not burst in water due to the presence of a sturdy cell wall. The cell wall provides structural support and rigidity, preventing excessive influx of water that could lead to lysis. Additionally, the vacuoles within the cells fill with water, creating turgor pressure that maintains cell shape without bursting.