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Plant and animal responses: OCR A‑Level Biology A questions

Every OCR A-Level Biology A exam question on 5.1.5 Plant and animal responses, 2016–2025, with its mark scheme and examiner’s report.

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1,984 questions

  1. Q11

    June 2025 · Paper 1

    1 mark5.1.5 Plant and animal responses
    The whole paper ↗
    June 2025 Paper 1, question 11: A student completes a series of experiments to investigate the role of auxin in apical dominance. The experimental procedures are shown in the table. Experiment

  2. Q18(a)

    June 2025 · Paper 1

    4 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2025 Paper 1, question 18(a): Describe the role of plant hormones in the control of seed germination. [4]

  3. Q18(b)

    June 2025 · Paper 1

    6 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2025 Paper 1, question 18(b): (b)* Scientists investigate the effect of gibberellin on stem length in young soybean plants. This is the method they use: • Select young plants with 4 pairs of

  4. Q18(c)

    June 2025 · Paper 1

    3 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2025 Paper 1, question 18(c): Soybeans are important food crops. Farmers often grow soybeans with the plants close together but this causes the stems to grow too long so that the plants fall

  5. Q2(c)

    June 2025 · Paper 3

    2 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2025 Paper 3, question 2(c): Heart rate is lowered when the heart receives stimulation from the vagus nerve. Explain why the vagus nerve is considered part of the peripheral nervous system

  6. Q3(a)

    June 2025 · Paper 3

    6 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2025 Paper 3, question 3(a): (a)* The three photomicrographs, D, E and F, show three different types of muscle tissue. D E F 9 State which photomicrograph shows cardiac muscle, which shows

  7. Q3(b)

    June 2025 · Paper 3

    3 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2025 Paper 3, question 3(b): The table lists events that occur during muscle contraction. Each event is represented by a letter. Letter Event H ATP binds to myosin, which causes myosin to d

  8. Q3(c)(ii)

    June 2025 · Paper 3

    2 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2025 Paper 3, question 3(c)(ii): Explain how the binding of antibodies to acetylcholine receptors in the neuromuscular junction reduces the rate at which Ca2+ ions bind to troponin. [2]

  9. Q19(a)(i)

    June 2024 · Paper 1

    1 mark5.1.5 Plant and animal responses
    The whole paper ↗
    June 2024 Paper 1, question 19(a)(i): Describe the meaning of the term tropism. [1]

  10. Q19(a)(ii)

    June 2024 · Paper 1

    1 mark5.1.5 Plant and animal responses
    The whole paper ↗
    June 2024 Paper 1, question 19(a)(ii): State one named example of a tropism. [1]

  11. Q19(a)(iii)

    June 2024 · Paper 1

    2 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2024 Paper 1, question 19(a)(iii): Give one example of an abiotic stress and the corresponding plant response. Example Plant response [2]

  12. Q19(b)(i)

    June 2024 · Paper 1

    1 mark5.1.5 Plant and animal responses
    The whole paper ↗
    June 2024 Paper 1, question 19(b)(i): Mycorrhizae are associations between some types of fungi and the roots of plants, including trees. The fungal hyphae grow into the roots and help the trees take

  13. Q19(b)(ii)

    June 2024 · Paper 1

    6 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2024 Paper 1, question 19(b)(ii): (ii)* The results are shown in the table. Mean PPO Activity ± Standard Deviation (Arbitrary Units) Group At start After 72 h 1 18 ± 2 20 ± 2 2 16 ± 2 50 ± 4 3 1

  14. Q20(a)(iv)

    June 2024 · Paper 1

    4 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2024 Paper 1, question 20(a)(iv): Use the data in Fig. 20.1 and Fig. 20.2 and your own knowledge of homeostatic control to explain the changes in breathing rate and heart rate during the experim

  15. Q11

    June 2023 · Paper 1

    1 mark5.1.5 Plant and animal responses
    The whole paper ↗
    June 2023 Paper 1, question 11: In a phototropism investigation oat seedlings were illuminated from one side as shown by the arrow in the table. The table shows the results of four different e

  16. Q17(a)(i)

    June 2023 · Paper 1

    2 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2023 Paper 1, question 17(a)(i): Explain why the Petri dishes were placed vertically and in the dark. [2]

  17. Q17(a)(ii)

    June 2023 · Paper 1

    2 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2023 Paper 1, question 17(a)(ii): Explain the purpose of the Petri dish containing distilled water instead of IAA solution. [2]

  18. Q17(b)

    June 2023 · Paper 1

    2 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2023 Paper 1, question 17(b): One of the students recorded the result shown in Table 17.1. Table 17.1 Mean root length in test solution Mean root length in water (number of grid squares) (nu

  19. Q17(c)(i)

    June 2023 · Paper 1

    4 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2023 Paper 1, question 17(c)(i): Plot a graph of the data in Table 17.2. [4]

  20. Q17(c)(ii)

    June 2023 · Paper 1

    2 marks5.1.5 Plant and animal responses
    The whole paper ↗
    June 2023 Paper 1, question 17(c)(ii): The students were given an IAA solution of concentration 100 ppm. Outline a procedure the students could use to prepare the 8 test solutions required for the ex
All 73 questions on Plant and animal responses, as a list
  1. June 2025, Paper 1, Q11 (1 mark): A student completes a series of experiments to investigate the role of auxin in apical dominance. The experimental procedures are shown in the table. Experiment
  2. June 2025, Paper 1, Q18(a) (4 marks): Describe the role of plant hormones in the control of seed germination. [4]
  3. June 2025, Paper 1, Q18(b) (6 marks): (b)* Scientists investigate the effect of gibberellin on stem length in young soybean plants. This is the method they use: • Select young plants with 4 pairs of
  4. June 2025, Paper 1, Q18(c) (3 marks): Soybeans are important food crops. Farmers often grow soybeans with the plants close together but this causes the stems to grow too long so that the plants fall
  5. June 2025, Paper 3, Q2(c) (2 marks): Heart rate is lowered when the heart receives stimulation from the vagus nerve. Explain why the vagus nerve is considered part of the peripheral nervous system
  6. June 2025, Paper 3, Q3(a) (6 marks): (a)* The three photomicrographs, D, E and F, show three different types of muscle tissue. D E F 9 State which photomicrograph shows cardiac muscle, which shows
  7. June 2025, Paper 3, Q3(b) (3 marks): The table lists events that occur during muscle contraction. Each event is represented by a letter. Letter Event H ATP binds to myosin, which causes myosin to d
  8. June 2025, Paper 3, Q3(c)(ii) (2 marks): Explain how the binding of antibodies to acetylcholine receptors in the neuromuscular junction reduces the rate at which Ca2+ ions bind to troponin. [2]
  9. June 2024, Paper 1, Q19(a)(i) (1 mark): Describe the meaning of the term tropism. [1]
  10. June 2024, Paper 1, Q19(a)(ii) (1 mark): State one named example of a tropism. [1]
  11. June 2024, Paper 1, Q19(a)(iii) (2 marks): Give one example of an abiotic stress and the corresponding plant response. Example Plant response [2]
  12. June 2024, Paper 1, Q19(b)(i) (1 mark): Mycorrhizae are associations between some types of fungi and the roots of plants, including trees. The fungal hyphae grow into the roots and help the trees take
  13. June 2024, Paper 1, Q19(b)(ii) (6 marks): (ii)* The results are shown in the table. Mean PPO Activity ± Standard Deviation (Arbitrary Units) Group At start After 72 h 1 18 ± 2 20 ± 2 2 16 ± 2 50 ± 4 3 1
  14. June 2024, Paper 1, Q20(a)(iv) (4 marks): Use the data in Fig. 20.1 and Fig. 20.2 and your own knowledge of homeostatic control to explain the changes in breathing rate and heart rate during the experim
  15. June 2023, Paper 1, Q11 (1 mark): In a phototropism investigation oat seedlings were illuminated from one side as shown by the arrow in the table. The table shows the results of four different e
  16. June 2023, Paper 1, Q17(a)(i) (2 marks): Explain why the Petri dishes were placed vertically and in the dark. [2]
  17. June 2023, Paper 1, Q17(a)(ii) (2 marks): Explain the purpose of the Petri dish containing distilled water instead of IAA solution. [2]
  18. June 2023, Paper 1, Q17(b) (2 marks): One of the students recorded the result shown in Table 17.1. Table 17.1 Mean root length in test solution Mean root length in water (number of grid squares) (nu
  19. June 2023, Paper 1, Q17(c)(i) (4 marks): Plot a graph of the data in Table 17.2. [4]
  20. June 2023, Paper 1, Q17(c)(ii) (2 marks): The students were given an IAA solution of concentration 100 ppm. Outline a procedure the students could use to prepare the 8 test solutions required for the ex
  21. June 2023, Paper 1, Q17(c)(iii) (2 marks): Describe two precautions the students should take to make sure the concentrations of the solutions they prepare are accurate. 1 2 [2]
  22. June 2023, Paper 1, Q17(c)(iv) (1 mark): Suggest why the range of IAA concentrations could be described as logarithmic. [1]
  23. June 2023, Paper 3, Q1(c) (2 marks): The nervous system of a cat coordinates a response to stop objects becoming stuck in their throat. Sensory receptors at the back of the throat detect the stimul
  24. June 2022, Paper 1, Q13 (1 mark): An electromyogram (EMG) records the electrical activity of a muscle. The figure shows an EMG trace of a muscle undergoing fatigue. 0 10 20 30 40 50 60 70 80 Tim
  25. June 2022, Paper 1, Q19(a) (3 marks): The table lists structural and functional differences between different types of muscle. Place a tick (3) in each box where the structure or function applies to
  26. June 2022, Paper 1, Q19(b)(i) (3 marks): Identify three proteins that make up the filaments labelled Z on Fig. 19.1. 1 2 3 [3]
  27. June 2022, Paper 1, Q19(b)(ii) (2 marks): Labels X and Y in Fig. 19.1 indicate two distinct bands. Explain why the two bands look different. [2]
  28. June 2022, Paper 1, Q19(b)(iii) (3 marks): Use your knowledge of the sliding filament model of muscle contraction to explain why Fig. 19.2 represents contracted muscle. [3]
  29. June 2022, Paper 1, Q19(c) (2 marks): After death, the concentration of ATP in muscle cells decreases. During this time, the muscles become rigid in a process called rigor mortis. Suggest why a lack
  30. June 2022, Paper 1, Q19(d) (6 marks): (d)* Muscle contraction requires energy in the form of ATP. Describe the different sources of the ATP that is used in muscle contraction during strenuous exerci
  31. June 2022, Paper 3, Q3(b)(i) (1 mark): Use the graph to estimate the auxin concentration at which inhibition of lateral shoots is 100%. Auxin concentration = mol dm–3 [1]
  32. June 2022, Paper 3, Q3(b)(ii) (1 mark): The student identified a possible anomaly in their results: the data point for the apical shoot receiving 10–6 mol dm–3 of auxin. State what the student could d
  33. June 2022, Paper 3, Q3(b)(iii) (3 marks): Using the graph, describe the conclusions that can be drawn about the role of different auxin concentrations in the control of apical dominance. [3]
  34. June 2022, Paper 3, Q3(c)(i) (1 mark): Suggest appropriate units for the dependent variable in this investigation. [1]
  35. June 2022, Paper 3, Q3(c)(ii) (6 marks): (ii)* The student has access to standard laboratory equipment and planting materials. Outline a method that the student could use to investigate the effect of g
  36. June 2022, Paper 3, Q3(d) (3 marks): A friend of the student had an apple tree in their garden. The friend asked the student if there was a way to ripen the fruit on the apple tree more quickly so
  37. November 2021, Paper 1, Q12 (1 mark): Which of the following statements is/are correct? 1 The autonomic nervous system contains sensory and motor neurones. 2 Somatic and parasympathetic motor neuron
  38. November 2021, Paper 1, Q16(a)(ii) (1 mark): State which subdivision of the peripheral nervous system supplies structure A on Fig. 16.1. [1]
  39. November 2021, Paper 1, Q16(b)(i) (2 marks): Identify the letter and name of the structure in Fig. 16.2 that is connected by nerves to structure A in Fig. 16.1. Letter Name [2]
  40. November 2021, Paper 1, Q16(b)(ii) (2 marks): Normal human resting heart rate is approximately 70 beats per minute (bpm). Cutting the parasympathetic nerve to the heart increases this to approximately 100 b
  41. November 2021, Paper 1, Q16(b)(iii) (2 marks): Injury to the parts of the brain labelled G and H in Fig. 16.2 can lead to a range of symptoms including: • fatigue • weight gain • menstrual irregularities • l
  42. November 2021, Paper 1, Q16(c) (2 marks): Complete the following passage using the most appropriate terms. The knee-jerk reflex is an example of a spinal reflex as it only goes through the whereas the b
  43. November 2021, Paper 3, Q3(d) (1 mark): Many plants have defensive responses to herbivores. State one example of a response that plants use against herbivory. [1]
  44. November 2020, Paper 3, Q3(a)(i) (6 marks): (i)* Describe and explain the results shown in Tables 3.1 and 3.2. [6] Additional answer space if required.
  45. November 2020, Paper 3, Q3(a)(ii) (1 mark): The students wanted to test whether there was a significant difference between the stem lengths of the seedlings in Group A and the seedlings in Group B. State
  46. November 2020, Paper 3, Q3(a)(iii) (1 mark): Justify your choice of statistical test given in part (ii). [1]
  47. November 2020, Paper 3, Q3(a)(iv) (3 marks): Table 3.2 records the direction of growth as: • away from light • neither away from nor towards light • towards light. The students used the chi‑squared test to
  48. November 2020, Paper 3, Q3(c)(i) (1 mark): State the name of a plant hormone that would be expected to affect root growth. [1]
  49. November 2020, Paper 3, Q3(c)(ii) (1 mark): In the investigation, the students controlled light, temperature and mineral concentration. State one other factor that the students should have controlled in t
  50. November 2020, Paper 3, Q3(d) (2 marks): The growth of plant roots is thought to be controlled by specialised cells called statocytes. One hypothesis for how a statocyte controls root growth involves s
  51. June 2019, Paper 1, Q7 (1 mark): The following passage outlines the process of phototropism in plants: Auxin is synthesised in cells at the of the shoot. Auxin causes the cells to on one side,
  52. June 2019, Paper 1, Q8 (1 mark): A scientist tested a plant suffering from water stress. The plant was found to have high levels of abscisic acid (ABA) in its tissues. Which of the following st
  53. June 2019, Paper 1, Q9 (1 mark): Which of the following statements, A to D, is evidence for geotropism? A leaves are shed from deciduous plants in the autumn B roots grow downwards C shoots gro
  54. June 2019, Paper 1, Q10 (1 mark): Many trees drop their leaves in the autumn. Which of the following plant hormones is/are thought to be involved in the control of leaf drop? 1 auxin 2 ethene 3
  55. June 2019, Paper 1, Q17(a) (3 marks): Explain why gibberellin is classed as a plant hormone. [3]
  56. June 2019, Paper 1, Q17(b)(i) (4 marks): Plot the results from Table 17 as a suitable graph. [4]
  57. June 2019, Paper 1, Q17(b)(ii) (1 mark): Gibberellin causes an increase in internodal length. State one other role of gibberellin in plants. [1]
  58. June 2019, Paper 1, Q22(e)(i) (1 mark): Explain why this relationship occurs in P. pusillus stems. [1]
  59. June 2019, Paper 1, Q22(e)(ii) (2 marks): Give two examples of the commercial uses of auxin. 1 2 [2]
  60. June 2019, Paper 3, Q5(b)(i) (2 marks): What additional information do the scientists need to confirm their hypothesis? [2]
  61. June 2019, Paper 3, Q5(b)(ii) (1 mark): Suggest one valid conclusion it is possible for the scientists to draw from the results in Fig. 5.1. [1]
  62. June 2019, Paper 3, Q5(b)(iii) (1 mark): The scientists also recorded the level of cannibalism amongst the beet armyworm larvae. Cannibalism was measured as the number of beet armyworm larvae eaten by
  63. June 2018, Paper 1, Q12 (1 mark): The image below is a diagram of the human brain. Z Y X W Which of the labelled regions would be directly involved in learning to play a musical instrument? A W
  64. June 2018, Paper 1, Q15 (1 mark): The drug metoprolol prevents stimulation of post-synaptic receptors in the sympathetic nervous system. Which of the following conditions could this drug be used
  65. June 2018, Paper 1, Q16(b)(ii) (3 marks): Explain why glucose is required for the contraction of skeletal muscle. [3]
  66. June 2018, Paper 1, Q23(b) (4 marks): The student wrote the following summary about the control of heart rate. When the heart rate is too low the level of carboxylic acid in the blood becomes higher
  67. June 2018, Paper 1, Q23(c)(i) (2 marks): Suggest how the Moro reflex helps to prevent harm to a newborn baby. [2]
  68. June 2018, Paper 1, Q23(c)(ii) (3 marks): The Moro reflex gradually disappears and usually stops completely after babies reach nine months. Other reflexes develop as children grow older. Describe a refl
  69. June 2017, Paper 1, Q14 (1 mark): The commercially grown tobacco plant, Nicotiana rustica, has many pests. One such insect pest is Manduca sexta, which causes damage to the stems and leaves of N
  70. June 2017, Paper 1, Q21(a) (6 marks): Plant hormones affect the growth of plant tissues in different ways. One such effect is to promote the formation of seedless fruit. Cytokinins are a group of pl
  71. June 2017, Paper 1, Q21(b) (6 marks): Another response affected by plant hormones is phototropism. A student completed an investigation into phototropism in cress seeds. This was the method used: •
  72. June 2017, Paper 3, Q5(b)(i) (2 marks): Suggest two symptoms of MS that might not be present in people with Guillain–Barré syndrome. Explain your answers. 1 2 [2]
  73. June 2017, Paper 3, Q5(b)(ii) (2 marks): Multiple sclerosis and Guillain–Barré syndrome both cause muscle weakness and loss of muscle function. Suggest and describe how the function of neuromuscular ju

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