Strips of plant tissue were immersed in a range of sucrose solutions of different concentrations. Their lengths were measured before immersion and after 30 minutes.

The graph shows the ratio of initial length to final length.

What is a correct description of the change in the cells and in their water potential as the sucrose concentration increases?

The stages of an investigation using plant tissue are listed below.
- A freshly cut slice of plant tissue was rinsed in distilled water, dried and weighed.
- This slice was placed in a solution with a water potential of -4 arbitrary units for thirty minutes.
- The slice was removed from the solution, dried and reweighed.
- The mass of the slice was the same as its original mass.

Which conclusions can be drawn from this investigation?
1 The water potential of the cells of the plant tissue is -4 arbitrary units.
2 The cell sap of the plant tissue has a lower water potential than the surrounding solution.

3 There has been no net movement of water.
4 The cell wall of the plant tissue will not be in contact with the cell membrane.

A student weighed a cylinder of potato and then put it into a test-tube containing a salt solution.
The potato cylinder was removed from the salt solution after one hour. It was blotted dry and then reweighed. The student recorded that the potato had lost mass.

Which row shows the correct explanation for the results the student collected?

Equal sized potato pieces were placed into a test-tube and covered with a sucrose solution. The test-tube was left for 30 minutes. All other variables were standardised.

After 30 minutes, the potato piece had not changed in size.
What can be concluded from this result?

Strips of potato tissue were immersed in distilled water or in sucrose solutions of different concentrations. The graph shows the percentage change in length of the potato tissue over time.

Which row correctly shows how the water potentials of the distilled water and sucrose solutions differ from the initial water potential of the potato tissue?

An experiment was carried out to investigate the effect of concentration of sucrose solution on cells in a plant tissue.

A sample of plant tissue was cut into seven cylinders of equal length and diameter. The mass of each cylinder was recorded.

Each of the seven cylinders was put into a different sucrose solution concentration.

After two hours, the cylinders were removed, blotted dry and reweighed. The percentage change in mass of each cylinder was recorded.

The graph shows the results of this investigation.
percentage change in mass of plant tissue cylinder

Which row explains the results if plant tissue cells were put in a sucrose solution of $0.45 \mathrm{moldm}^{-3}$ ?

A student carried out an investigation to estimate the water potential of potato tissue. The main steps in the procedure and in the analysis of results are outlined in Fig. 6.1.

Six different concentrations of sucrose solution were prepared and an equal volume of each was placed in a labelled beaker. Six equal-sized blocks of potato tissue were cut out of the same potato, blotted dry and weighed.

One potato block was immersed in the solution in each beaker for 30 minutes.

After this time, the block was removed, blotted dry and reweighed.

The experiment was repeated twice.

The mean percentage change in mass of potato tissue was calculated for each concentration of sucrose used.

A graph was drawn of mean percentage change in the mass of potato tissue against concentration of sucrose.