WJEC Biology for A2 Level: Revision Workbook

Preparing for the examination Types of exam question There are two main types of questions in the exam. 1. Short-answer structured questions The majority of questions fall into this category. These questions may require description, explanation, application, and/or evaluation, and are generally worth 6−10 marks. Application questions could require you to use your knowledge in an unfamiliar context or to explain experimental data. The questions are broken down into smaller parts, e.g. (a), (b), (c), etc., which can include some 1-mark name or state questions, but most will require description, explanation or evaluation for 2−5 marks. You could also be asked to complete a table, label or draw a diagram, plot a graph, or perform a mathematical calculation. Some examples requiring ‘name’, ‘state’ or ‘define’: ⦁ Define the term biodiversity. (1 mark) ⦁ State the term used to describe the transfer of energy between consumers. (1 mark) ⦁ Name the cells shown that are undergoing meiosis. (1 mark) ⦁ Identify hormone A shown in the graph. (1 mark) Some examples requiring mathematical calculation: ⦁ The magnification of the image above is × 32,500. Calculate the actual width of the organelle in micrometres between points A and B. (2 marks) ⦁ Using the graph, calculate the initial rate of reaction for the enzyme. (2 marks) ⦁ Calculate the percentage energy lost through respiration by secondary consumers. (2 marks) ⦁ Use the Hardy–Weinberg formula to estimate the number of individuals in a population of 1000 that would be carriers of the condition. (4 marks) ⦁ Calculate χ 2 for the results of the cross shown. (3 marks) Some examples requiring description: ⦁ Describe how biodiversity loss could be delayed. (1 mark) ⦁ Describe how a sweep net could be used to estimate the diversity index of insects at the base of a hedge. (3 marks) Some examples requiring explanation: ⦁ Suggest one limitation of the method used and explain how this could have affected the validity of the conclusion drawn. (2 marks) ⦁ Explain why there must be three bases in each codon to assemble the correct amino acid. (2 marks) ⦁ Explain the term planetary boundary. (2 marks) ⦁ Explain why it is important when using a biosensor to measure urea concentration to maintain a constant temperature and pH. (2 marks) ⦁ Explain how the structures of cellulose and chitin are different from that of starch. (2 marks) Some examples requiring application: ⦁ Suggest the function of NAD in the series of reactions shown. (1 mark) ⦁ A drug has been shown to block the initiation of S phase in mitosis. Suggest why this could be used to treat cancer. (3 marks) ⦁ Use the information provided to explain why sodium benzoate would affect the accuracy of the biosensor. (5 marks) Some examples requiring evaluation: ⦁ Describe how you could improve your confidence in your conclusion. (2 marks) ⦁ Analyse the data in the table and draw alternative conclusions. Explain how you reached these conclusions. (3 marks) ⦁ Evaluate the strength of their evidence and hence the validity of their conclusion. (4 marks) 10 | WJEC Biology for A2 Level: Revision Workbook | Introduction Copyright: Sample material