AQA
A-Level
BIOLOGY
3.2a Cells
2.8-2.9 | Transport across Cell Membranes
Time allowed
60 minutes
QUESTION PAPER
Score Percentage
/49 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1
,.A group of students carried out an investigation to find the water potential of potato tissue.
The students were each given a potato and 50 cm3 of a 1.0 mol dm−3 solution of sucrose.
• They used the 1.0 mol dm−3 solution of sucrose to make a series of different
concentrations.
• They cut and weighed discs of potato tissue and left them in the sucrose solutions
for a set time.
• They then removed the discs of potato tissue and reweighed them.
The table below shows how one student presented his processed results.
Concentration of Percentage change
sucrose solution / mol in mass of potato
dm−3 tissue
0.15 +4.7
0.20 +4.1
0.25 +3.0
0.30 +1.9
, 0.35 −0.9
0.40 −3.8
(a) Explain why the data in the table above are described as processed results.
........................................................................................................................
........................................................................................................................
(1)
(b) Describe how you would use a 1.0 mol dm−3 solution of sucrose to produce 30 cm3
of a 0.15 mol dm−3 solution of sucrose.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(c) Explain the change in mass of potato tissue in the 0.40 mol dm−3 solution of sucrose.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(d) Describe how you would use the student’s results in the table above to find the
water potential of the potato tissue.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
A-Level
BIOLOGY
3.2a Cells
2.8-2.9 | Transport across Cell Membranes
Time allowed
60 minutes
QUESTION PAPER
Score Percentage
/49 %
4.1 | CELL BIOLOGY | QUESTION PAPER 1 1
,.A group of students carried out an investigation to find the water potential of potato tissue.
The students were each given a potato and 50 cm3 of a 1.0 mol dm−3 solution of sucrose.
• They used the 1.0 mol dm−3 solution of sucrose to make a series of different
concentrations.
• They cut and weighed discs of potato tissue and left them in the sucrose solutions
for a set time.
• They then removed the discs of potato tissue and reweighed them.
The table below shows how one student presented his processed results.
Concentration of Percentage change
sucrose solution / mol in mass of potato
dm−3 tissue
0.15 +4.7
0.20 +4.1
0.25 +3.0
0.30 +1.9
, 0.35 −0.9
0.40 −3.8
(a) Explain why the data in the table above are described as processed results.
........................................................................................................................
........................................................................................................................
(1)
(b) Describe how you would use a 1.0 mol dm−3 solution of sucrose to produce 30 cm3
of a 0.15 mol dm−3 solution of sucrose.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(c) Explain the change in mass of potato tissue in the 0.40 mol dm−3 solution of sucrose.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(d) Describe how you would use the student’s results in the table above to find the
water potential of the potato tissue.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
