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Oxford Cambridge and RSA
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fdWednesday 18 June 2025 – Morning
76hghjkahbcv ;zyhg;aurghaj rgggggaaaa r
edA Level Biology B (Advancing Biology)rtrtryyyt
A-Level OCR 2025 Biology B
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qwH422/03 Practical skills in biology (Advancing Biology) Paper 3
Dfwewe344t5656564
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tiTime allowed: 1 hour 30 minutes
433ffhbyuyii7n689888898
Turn over
, 2
1 Two functions of the roots of plants are to take up water from the soil and to store starch.
(a) The photomicrograph shows a transverse section of a root in a monocotyledonous plant.
A
C
B
× 20
(i) The cells labelled A and B are two different types of cell in the vascular tissue of the root.
Identify the types of cell labelled A and B.
A .......................................................................................................................................................
B .......................................................................................................................................................
[2]
(ii) The diameter of one region of the root is represented by the line C in the image.
The magnification used to produce the image was × 20.
Calculate the actual diameter of C.
Give your answer in mm.
Diameter =........................................................... mm [2]
(iii) One risk when dissecting plant tissues, such as roots, is the potential for injury when using sharp
instruments.
State one other health and safety risk that should be considered before dissecting plant tissues.
..........................................................................................................................................................
...................................................................................................................................................................... [1]
© OCR 2025
, 3
(b) A scientist investigates how the rate of water uptake by roots is affected by the presence of salt
(NaCl) in the surrounding soil.
This is the method they use:
• Grow 110 tomato plants in pots of soil in a greenhouse.
• Add 50 mmol dm–3 salt solution to the soil of 55 plants, every day.
• The other 55 plants are a control group.
• Calculate the rate of water uptake per day (dm3 d–1) by the roots of each plant.
The results of the investigation are shown in the graph.
2.5
Key:
control
salt solution
2.0
Mean 1.5
rate of
water
uptake
(dm3 d–1) 1.0
0.5
0.0
0 20 40 60 80 100 120 140 160
Time (days)
(i) State how the group of control plants would be set up differently to the group of plants given salt
solution and explain the purpose of this control group.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
...................................................................................................................................................................... [2]
(ii) Calculate the largest percentage difference in water uptake between the plants in the control
group and the plants given salt solution.
Use your answer to complete the sentence.
On day ............................. the water uptake of the control plants was................................. % greater
than the water uptake of the plants given the salt solution. [2]
© OCR 2025 Turn over
Oxford Cambridge and RSA
dgdgdgsaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrggggggggggggggggggsssssssssssssssssssssssssssssssggggggggg
ggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
fdWednesday 18 June 2025 – Morning
76hghjkahbcv ;zyhg;aurghaj rgggggaaaa r
edA Level Biology B (Advancing Biology)rtrtryyyt
A-Level OCR 2025 Biology B
Dszxewwwwwwwv eeeeeeeeeeeeeeeeeeeeeeeeeffffffffffffffwq
qwH422/03 Practical skills in biology (Advancing Biology) Paper 3
Dfwewe344t5656564
B-bhgyyyyyyyyyyyyy
tiTime allowed: 1 hour 30 minutes
433ffhbyuyii7n689888898
Turn over
, 2
1 Two functions of the roots of plants are to take up water from the soil and to store starch.
(a) The photomicrograph shows a transverse section of a root in a monocotyledonous plant.
A
C
B
× 20
(i) The cells labelled A and B are two different types of cell in the vascular tissue of the root.
Identify the types of cell labelled A and B.
A .......................................................................................................................................................
B .......................................................................................................................................................
[2]
(ii) The diameter of one region of the root is represented by the line C in the image.
The magnification used to produce the image was × 20.
Calculate the actual diameter of C.
Give your answer in mm.
Diameter =........................................................... mm [2]
(iii) One risk when dissecting plant tissues, such as roots, is the potential for injury when using sharp
instruments.
State one other health and safety risk that should be considered before dissecting plant tissues.
..........................................................................................................................................................
...................................................................................................................................................................... [1]
© OCR 2025
, 3
(b) A scientist investigates how the rate of water uptake by roots is affected by the presence of salt
(NaCl) in the surrounding soil.
This is the method they use:
• Grow 110 tomato plants in pots of soil in a greenhouse.
• Add 50 mmol dm–3 salt solution to the soil of 55 plants, every day.
• The other 55 plants are a control group.
• Calculate the rate of water uptake per day (dm3 d–1) by the roots of each plant.
The results of the investigation are shown in the graph.
2.5
Key:
control
salt solution
2.0
Mean 1.5
rate of
water
uptake
(dm3 d–1) 1.0
0.5
0.0
0 20 40 60 80 100 120 140 160
Time (days)
(i) State how the group of control plants would be set up differently to the group of plants given salt
solution and explain the purpose of this control group.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
...................................................................................................................................................................... [2]
(ii) Calculate the largest percentage difference in water uptake between the plants in the control
group and the plants given salt solution.
Use your answer to complete the sentence.
On day ............................. the water uptake of the control plants was................................. % greater
than the water uptake of the plants given the salt solution. [2]
© OCR 2025 Turn over
