An investigation was carried out to study how temperature affects the decay of different milk varieties (Whole Milk, Soy Milk, and Almond Milk). During decay, decomposer microorganisms break down nutrients in the milk, producing organic acids that lower the pH.
The graph below shows the time taken (in hours) for each type of milk to reach a pH of 4.8 at different temperatures.
Which type of milk remains fresh the longest at 20 ∘C20\ ^\circ\text{C}20 ∘C?
Describe the effect of temperature on the time taken for Whole milk to reach pH 4.8. Use data from the graph in your answer.
The time taken for Soy milk to reach pH 4.8 at 25 ∘C25\ ^\circ\text{C}25 ∘C is less than at 15 ∘C15\ ^\circ\text{C}15 ∘C. Suggest one reason why.
Organisation of an ecosystem Questions
Practise AQA GCSE Biology Organisation of an ecosystem with exam-style questions for Foundation and Higher tier. 24 questions covering Levels of organisation, How materials are cycled, Decomposition (biology only), and Impact of environmental change (biology only) (HT only), matched to the AQA GCSE Biology (8461) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.