AQA a level biology paper 2 // 13th June 2019 // unofficial mark scheme LIST

Predictions on grade boundaries guys?
I felt the exam was reasonable but this is relative to the specificity of the mark scheme. Similar to 2017 Gb imo, if not lower

Why add glucose solution for growth (question)

- The question stated the room was dark so therefore light is not present to initiate the light-dependent and light-independent stage (the calvin cycle) where sugars are produced.
- The glucose solution (absorbed by roots?) is used in respiration for growth.

Why does adenylate cyclase (being inhibited) reduce glucose concentration (question)

- I believe the question referred to the enzyme being inhibited so the enzyme (adenyl cyclase) could not bind to the substrate ATP (could state that no E-S complexes form) to form product cAMP.
- cAMP is the second messenger to activate enzyme kinase (protein) which catalyses glycogenolysis (converts starch or fat into glucose) which moves by facilitated diffusion out of liver into bloodstream.

but the shoots can't carry out photosynthesis because they don't have leaves yet, I said the glucose is used to respire, and without the glucose the cells would die so there would be no growth, which would affect the results of the experiment

Agreed, same or slightly lower/higher by a mark so around 50

Good point I didn't actually think about that, now I feel stupid