Skip to content
Try on iPad

Application of reproduction and genetics: WJEC A‑Level Biology questions

Every WJEC A-Level Biology exam question on 4.5 Application of reproduction and genetics, 2016–2025, with its mark scheme and examiner’s report.

Find questions1,223
Calculations

1,223 questions

  1. Q3(b)(i)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 3(b)(i): As the morphology of the two subspecies of Pediculus is similar, it is difficult to distinguish between them. By comparing base sequences of DNA from head lice

  2. Q3(b)(ii)

    Summer 2025 · Unit 4

    2 marks4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 3(b)(ii): I. Describe the structure of a primer. [1] II. Explain the function of a primer within the PCR process. [1]

  3. Q3(b)(iii)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 3(b)(iii): Taq DNA polymerase is extracted from the bacterium Thermus aquaticus, which lives in hot springs. Explain the reason for using DNA polymerase from this organism

  4. Q3(b)(iv)

    Summer 2025 · Unit 4

    2 marks4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 3(b)(iv): Use the formula below to calculate the number of copies of DNA that should be present in the thermocycler after 30 cycles of the PCR process if one molecule of

  5. Q3(b)(v)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 3(b)(v): After approximately 20 cycles, the production of DNA copies reaches a plateau. Suggest one reason why the number of DNA copies may be fewer than expected after

  6. Q3(c)(i)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 3(c)(i): The genomes of both subspecies of Pediculus have been sequenced. Explain how this information might be used to benefit present day human populations that may be

  7. Q5(b)(i)

    Summer 2025 · Unit 4

    3 marks4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 5(b)(i): I. Use the information above to explain why there was a four-month time interval between transfusions. [2] II. Suggest why laboratory-produced red blood cells r

  8. Q5(b)(ii)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 5(b)(ii): Explain why it was important to carry out each trial using the same volunteers. [1]

  9. Q5(b)(iii)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 5(b)(iii): Embryonic stem cells could provide an alternative source of stem cells. They have the ability to differentiate into any type of cell if given the correct chemic

  10. Q5(c)(i)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 5(c)(i): The increase in blood haemoglobin concentration during the first six months following stem cell transfer is considered significant. Use Graph 5.2 to explain why

  11. Q5(c)(ii)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 5(c)(ii): Use the information provided to explain one advantage of this type of gene therapy as a treatment for sickle cell disease compared to the transfusion of red blo

  12. Q5(c)(iii)

    Summer 2025 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2025 Unit 4, question 5(c)(iii): Suggest one potential disadvantage associated with the use of this gene therapy procedure for treating sickle cell disease. [1]

  13. Q3(a)

    Summer 2024 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2024 Unit 4, question 3(a): The human genome project determined the base pairs that make up human DNA. Explain how the results from the human genome project have allowed the synthesis of t

  14. Q3(b)

    Summer 2024 · Unit 4

    3 marks4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2024 Unit 4, question 3(b): State three advantages of using an artificially synthesised gene rather than extracting the gene from the human genome. [3] The plasmid used to genetically modi

  15. Q3(c)

    Summer 2024 · Unit 4

    2 marks4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2024 Unit 4, question 3(c): Name the two types of enzymes needed for the successful insertion of the human growth hormone gene and state their function in the process. [2] To test that the

  16. Q3(d)(i)

    Summer 2024 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2024 Unit 4, question 3(d)(i): Explain the need for Plate A in the process. [1]

  17. Q3(d)(ii)

    Summer 2024 · Unit 4

    3 marks4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2024 Unit 4, question 3(d)(ii): Explain the results shown on Plate B. [3]

  18. Q3(d)(iii)

    Summer 2024 · Unit 4

    1 mark4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2024 Unit 4, question 3(d)(iii): Suggest one vital property of the cells on Plate C which would need to be confirmed prior to their use in the production of HGH. [1]

  19. Q3(e)

    Summer 2024 · Unit 4

    2 marks4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2024 Unit 4, question 3(e): molecules of HGH. If there are 1 × 108 bacteria in the culture vessel, calculate the number of HGH molecules being produced by the cells. Give your answer in st

  20. Q5(a)(i)

    Summer 2023 · Unit 4

    3 marks4.5 Application of reproduction and genetics
    The whole paper ↗
    Summer 2023 Unit 4, question 5(a)(i): Explain the following processes during the PCR: [3] I. a single stranded DNA primer is added; II. the DNA is heated to 95°C at the start of a cycle; III. the DN
All 40 questions on Application of reproduction and genetics, as a list
  1. Summer 2025, Unit 4, Q3(b)(i) (1 mark): As the morphology of the two subspecies of Pediculus is similar, it is difficult to distinguish between them. By comparing base sequences of DNA from head lice
  2. Summer 2025, Unit 4, Q3(b)(ii) (2 marks): I. Describe the structure of a primer. [1] II. Explain the function of a primer within the PCR process. [1]
  3. Summer 2025, Unit 4, Q3(b)(iii) (1 mark): Taq DNA polymerase is extracted from the bacterium Thermus aquaticus, which lives in hot springs. Explain the reason for using DNA polymerase from this organism
  4. Summer 2025, Unit 4, Q3(b)(iv) (2 marks): Use the formula below to calculate the number of copies of DNA that should be present in the thermocycler after 30 cycles of the PCR process if one molecule of
  5. Summer 2025, Unit 4, Q3(b)(v) (1 mark): After approximately 20 cycles, the production of DNA copies reaches a plateau. Suggest one reason why the number of DNA copies may be fewer than expected after
  6. Summer 2025, Unit 4, Q3(c)(i) (1 mark): The genomes of both subspecies of Pediculus have been sequenced. Explain how this information might be used to benefit present day human populations that may be
  7. Summer 2025, Unit 4, Q5(b)(i) (3 marks): I. Use the information above to explain why there was a four-month time interval between transfusions. [2] II. Suggest why laboratory-produced red blood cells r
  8. Summer 2025, Unit 4, Q5(b)(ii) (1 mark): Explain why it was important to carry out each trial using the same volunteers. [1]
  9. Summer 2025, Unit 4, Q5(b)(iii) (1 mark): Embryonic stem cells could provide an alternative source of stem cells. They have the ability to differentiate into any type of cell if given the correct chemic
  10. Summer 2025, Unit 4, Q5(c)(i) (1 mark): The increase in blood haemoglobin concentration during the first six months following stem cell transfer is considered significant. Use Graph 5.2 to explain why
  11. Summer 2025, Unit 4, Q5(c)(ii) (1 mark): Use the information provided to explain one advantage of this type of gene therapy as a treatment for sickle cell disease compared to the transfusion of red blo
  12. Summer 2025, Unit 4, Q5(c)(iii) (1 mark): Suggest one potential disadvantage associated with the use of this gene therapy procedure for treating sickle cell disease. [1]
  13. Summer 2024, Unit 4, Q3(a) (1 mark): The human genome project determined the base pairs that make up human DNA. Explain how the results from the human genome project have allowed the synthesis of t
  14. Summer 2024, Unit 4, Q3(b) (3 marks): State three advantages of using an artificially synthesised gene rather than extracting the gene from the human genome. [3] The plasmid used to genetically modi
  15. Summer 2024, Unit 4, Q3(c) (2 marks): Name the two types of enzymes needed for the successful insertion of the human growth hormone gene and state their function in the process. [2] To test that the
  16. Summer 2024, Unit 4, Q3(d)(i) (1 mark): Explain the need for Plate A in the process. [1]
  17. Summer 2024, Unit 4, Q3(d)(ii) (3 marks): Explain the results shown on Plate B. [3]
  18. Summer 2024, Unit 4, Q3(d)(iii) (1 mark): Suggest one vital property of the cells on Plate C which would need to be confirmed prior to their use in the production of HGH. [1]
  19. Summer 2024, Unit 4, Q3(e) (2 marks): molecules of HGH. If there are 1 × 108 bacteria in the culture vessel, calculate the number of HGH molecules being produced by the cells. Give your answer in st
  20. Summer 2023, Unit 4, Q5(a)(i) (3 marks): Explain the following processes during the PCR: [3] I. a single stranded DNA primer is added; II. the DNA is heated to 95°C at the start of a cycle; III. the DN
  21. Summer 2023, Unit 4, Q5(a)(ii) (1 mark): Explain why a certain type of polymerase, called Taq polymerase, is necessary in the final extension stage of the cycle at 70°C. [1] The researchers collected e
  22. Summer 2023, Unit 4, Q5(e) (2 marks): Ivory from elephant tusks contains DNA. Suggest how the data on the DNA profiles of populations could help with combatting poaching. [2]
  23. Summer 2023, Unit 4, Q6 (9 marks): The Human Genome Project was completed in April 2003 when an accurate and complete human genome sequence was made available to scientists and researchers. As a
  24. Summer 2022, Unit 4, Q3(b)(i) (2 marks): State why stem cells must be used in this technique. [2]
  25. Summer 2022, Unit 4, Q3(b)(ii) (2 marks): Describe two advantages of using this type of stem cell treatment over using embryonic stem cells. [2] The gene editing relies on the RNA guide recognising a ta
  26. Summer 2022, Unit 4, Q3(b)(iii) (2 marks): Suggest how the results of the Human Genome Project has made the use of this gene editing technique possible. [2]
  27. Summer 2019, Unit 3, Q5(c)(i) (1 mark): A sample of DNA was taken from each of the varieties. State the technique that could be used to show the relatedness of the two varieties of barnacles. [1]
  28. Summer 2019, Unit 4, Q2(c)(i) (2 marks): State what information has been obtained from the Anopheles and Plasmodium Genome Projects. [2]
  29. Summer 2019, Unit 4, Q2(c)(ii) (2 marks): State two uses of the information obtained from these genome projects in the control of malaria. [2]
  30. Summer 2019, Unit 4, Q7 (9 marks): Plants, such as maize (Zea sp.), can be genetically modified to provide resistance to insect pests. The bacterium, Bacillus thuringiensis, naturally produces a
  31. Summer 2018, Unit 4, Q4(d)(i) (1 mark): On the diagram above complete the nucleotide sequence of the DNA primer complementary to the strand of DNA. [1]
  32. Summer 2018, Unit 4, Q4(d)(ii) (1 mark): Explain why two different DNA primers are required. [1]
  33. Summer 2018, Unit 4, Q4(d)(iii) (1 mark): A sample of blood from a pregnant woman is taken. Primers specific to a gene on chromosome 21 are used to replicate it. Primers specific to another gene on a di
  34. Summer 2018, Unit 4, Q4(d)(iv) (2 marks): After the PCR, the DNA fragments are separated using gel electrophoresis and the level of fluorescence for each gene is measured. The level of fluorescence corr
  35. Summer 2018, Unit 4, Q4(d)(v) (4 marks): The diagram below shows the quantity of genes from chromosome 21 and the quantity of the control gene following PCR in three pregnant women A, B and C. 0.7 gene
  36. Summer 2018, Unit 4, Q4(e) (2 marks): Suggest two concerns that some people may have about the ethics of prenatal diagnosis. [2]
  37. Summer 2017, Unit 4, Q2(c) (2 marks): Through gene therapy, it is hoped that the functional version of the gene can be isolated and introduced into muscle cells. Historically, a virus has been used
  38. Summer 2017, Unit 4, Q2(d)(iii) (1 mark): There is another drug available which is used to remove mutated exons from the dystrophin gene. State the advantage of using this drug to treat DMD rather than
  39. Summer 2017, Unit 4, Q2(d)(iv) (1 mark): Scientists are also investigating a means of using a molecular patch for germ line gene therapy. State one ethical issue of using germ line gene therapy in the
  40. Summer 2017, Unit 4, Q3(a)(iv) (3 marks): The inheritance of mitochondrial diseases can be prevented using the technique outlined in the following diagram. healthy donor’s DONOR nuclear DNA is EGG remov

Questions, mark schemes and examiner’s reports are © WJEC CBAC Ltd, from their published past papers. Plumi isn’t affiliated with any exam board. Want whole papers? Every WJEC A-Level Biology paper.

Rather write your answers by hand on iPad? Plumi marks them against the same mark schemes.