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0610/51 — Paper 5 Practical Test

Cambridge Assessment International Education · October/November 2025

DOCUMENTS
CI · QP · MS
TOTAL PAGES
35
QUESTIONS
17
MARKS
40
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WHAT THIS PAPER ASKS YOU TO DO

Question 1PRACTICAL

Dye movement in celery stalks vs temperature

Compare how far a coloured dye travels up celery stalks standing in ice-cold and warm water baths, then measure an insect photograph and draw a celery leaf.

[26]
  1. 1(a)(i)Record the starting temperatures of the water in large beaker C and large beaker W in Table 1.1, then (later) their final temperatures.[1]
  2. 1(a)(ii)Prepare a table and record your results. Include the number of 5 mm sections cut before the dye was no longer visible, and the total distance moved by the coloured dye, for both celery stalks.[5]
  3. 1(a)(iii)Calculate the rate of movement of the dye in the celery stalk in beaker W. Include the unit.[2]
  4. 1(a)(iv)State a conclusion for this investigation.[1]
  5. 1(a)(v)This investigation was only done once. Explain why it is better to repeat an investigation.[1]
  6. 1(b)Identify two variables that were kept constant in this investigation.[2]
  7. 1(c)(i)The data you have recorded in Table 1.1 may indicate that there is a source of error with the method used in this investigation. Identify the possible error and describe an improvement to the method to reduce the effect of this error.[2]
  8. 1(c)(ii)In step 9, it is difficult to determine precisely the final position of the dye in the xylem. Suggest an improvement to the method that would reduce this source of error.[1]
  9. 1(d)(i)Line AB represents the body length of the black aphid in Fig. 1.5 (magnification ×35). Measure line AB, then calculate the actual body length of the black aphid using magnification = (length of line AB) / (actual body length). Give your answer to one significant figure.[3]
  10. 1(d)(ii)State three ways that the leaf miner fly shown in Fig. 1.6 differs from the black aphid shown in Fig. 1.5.[3]
  11. 1(e)Fig. 1.7 is a photograph of a celery leaf. Draw a large diagram of the celery leaf shown in Fig. 1.7.[4]
  12. 1(f)Carbon dioxide moves into celery leaves for photosynthesis. State the name of an indicator which could be used to test for the presence of carbon dioxide gas.[1]
Sit this question →Run it on the guided bench →
Question 2PRACTICAL

Height and vital capacity

Name the protein-test reagent, then plot and interpret a printed data set relating a person's height to their lung vital capacity.

[8]
  1. 2(a)In people with certain lung diseases the enzyme elastase is more active. Elastase is a protein. State the name of the reagent that is used to test for protein.[1]
  2. 2(b)(i)Plot a line graph on the grid of the data in Table 2.1 (height of the person vs vital capacity).[4]
  3. 2(b)(ii)Describe the relationship shown in your graph between height and vital capacity.[1]
  4. 2(b)(iii)Use your graph to estimate the vital capacity of a person who has a height of 175 cm. Indicate on your graph how you obtained your estimate.[2]
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Question 3WRITTEN ONLY

Planning: pH and amylase activity

Written only — plan an investigation into the effect of pH on amylase activity, using iodine solution.

[6]
  1. 3Amylase is an enzyme that catalyses the breakdown of starch to form reducing sugars. Plan an investigation to determine the effect of pH on the activity of amylase. Use iodine solution in your method.[6]
Sit this question →

What the lab technician is told: exact solutions, concentrations and apparatus to set out. This is where the bench comes from.

QUESTION 1 — MATERIALS

Prepared fresh on the day of the exam.

  • celery stalks— Apium graveolens, leaves removed, cut to approximately 10 cm length, presented on a white tile2
  • 100 cm³ beaker of dye— dye to a depth of 1 cm from the bottom (approximately 25 cm³), labelled 'dye' — a water-based dark food colouring, strong enough to clearly stain the vascular bundles2
  • 250 cm³ beaker of ice-cold water— depth of 2 cm from the bottom (approximately 60 cm³), labelled C — the cold water-bath1
  • empty 250 cm³ beaker labelled W— filled with warm water (40–50 °C, approximately 60 cm³) only once the candidate raises their hand to request it1

QUESTION 1 — APPARATUS

  • white tile1
  • thermometer— −10 °C to +110 °C, 1 °C graduations1
  • stop-clock1
  • knife or scalpel1
  • hand lens— at least ×6 magnification1
  • permanent marker pen1
  • 30 cm ruler with a mm scale— also needed for Question 21
  • paper towels5
  • suitable eye protection1
  • gloves1 pair

⚠ No hazards are flagged for this paper — celery, food dye and water only. The 30 cm ruler is shared with Question 2, which otherwise needs no apparatus of its own.

THE CURATED BENCHES BUILT FROM THIS

Same skills, taught rather than examined — guided step by step, with the apparatus mistakes explained as you make them.

Dye uptake in celery: does warmer water speed up the xylem stream? →