2018 Paper 1

• There was also evidence throughout the paper of students not using the information provided in the question stems.

  • If a specific figure or table is referenced in a question, the marks will be directly related to it.
• • When asked for a method, students must write out what actions need to be carried out as if instructing a fellow student.
  • Students should give specific instructions about how the results would be obtained
  • for example using a water bath set to 30°C!!!
  • removing the potato chips every 10 minutes to record their mass, and blotting the potato chips dry with a paper towel.
• Both conclusions were comparative statements, natural habitat being the most favourable and town habitat being the least favourable, and so the marking points were linked to comparative statements between the habitats.

  If question is being COMPARATIVE, YOU MUST ANSWER IN COMPARATIVE STATEMENTS
• • Numbers were provided on the axes and so quoting days of the year was expected in the answers.
  • This question provides a good example to demonstrate the importance of using and quoting the correct evidence from the data when trying to support the conclusions.

  MUST USE DATA TRYING TO SUPPORT CONCLUSIONS
• It was hoped that A-level students could be SPECIFIC!!!!! about why collecting more data would be beneficial.

  • For example, they were told that these graphs were drawn following collection from FOUR DATA POINTS –
  • students should be aware from their graphical work that this would not result in an accurate line of best fit, or that intermediate points could not be determined from these few data points
• 3. Collected from more sites/more years to increase accuracy of (mean) data // representative
• 1. Very, very few students could use their knowledge of section 3.4.6 to point out that these data would have been more meaningful if numbers of each species had been counted so that an index of diversity could be calculated
  2. If question about biodiversity, INDEX OF DIVERSITY MUST BE CALCULATED
  3. Collect at more times of the year so more points on graph/better line (of best fit) on graph; MUST RELATE TO GRAPH!!!!
• • In question 04.1, although many students could describe that the enzyme lowers the activation energy
  • only 18% could explain that this was due to the enzyme BENDING the bonds in the substrate.
  • ‘Due to stress/pressure/tension on bonds
  • OR ‘Due to weakening bonds’
• • Imprecise biological language was also often seen, for example omitting to reference the ‘SHAPE’ of the active site and
  • discussing the 3-D structure of the protein rather than its TERTIARY structure.
• Those who were not awarded marking point two tended not to make a comparative statement about active and passive immunity, and some made vague statements about active immunity ‘taking time’, rather than expressing length of time

  • Passive immunity is FASTER OR
  • Active immunity would be too slow / slower
• 1. Too many generalised answers were given to question 07.4. At this level, a SPECIFIC reason why it would be ethical to have veterinary supervision in this particular procedure was required.
  2. (So) the animal does not suffer from the venom/vaccine/toxin;
  3. 3. (So) the animal does not have PATHOGEN that could be transferred to humans; - when vaccination
• • The first point was for the idea that the radioactive carbon dioxide would be used in the leaf to produce sugar in photosynthesis.
  • The second point was then that sugar is transported in the phloem.
  • students could score the second marking point for appreciating that MASS FLOW/TRANSLOCATION happens in the phloem - using KEY TERMS
• • As with question 08.1, this part required students to explain the data, so answers required application of knowledge in the context of the question.
  • Some did not sufficiently link their knowledge that water moves to the leaf in the xylem with these data to achieve the second marking point, i.e. that water is still moving into the leaf in the xylem.
• Question 09.2 was another that required explanations of results, so the students were expected to USE SOME KNOWLEDGE within each marking point.

  • Able students responded with clear explanations about the effects of the antibody and how the RNA could prevent translation
  • using correct TECHNICAL language and an appropriate level of KNOWLEDGE for an A-level question.
• In question 10.2, although many students could demonstrate knowledge of phospholipids and triglycerides individually, they struggled to complete the required ‘compare and contrast’ command.

  • When this command is used, every marking point requires a COMPARATIVE statement that must be clearly made by the student:
  • examiners will not infer links between separate statements - descriptions of phospholipids and of triglycerides