A-Level BiologyYear 2017Q10
Page 07 10. The fungus Aspergillus niger is grown in large fermenters to produce citric acid using starch as a substrate. The graph shows the changes in the citric acid and starch concentrations in a fermenter over 168 hours. 168 144 120 96 72 48 24 0 60 50 40 30 20 10 0 30 25 20 15 10 5 0 Time (hours) Starch concentration (g/100 ml) Citric acid concentration (g/100 ml) The citric acid concentration equals the starch concentration at A 0 hours B 48 hours C 72 hours D 120 hours. [Turn over
Paper Source:NH_Biology_all_2017.pdf
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Exam Specification Info
This question is part of the UK A-Level Biology syllabus. In the actual exam, structured questions typically require linking specific keywords to gain full marks. Applaa helps you drill these topics.
Syllabus levelAdvanced Level (A-Level)
SubjectBiology
Official MarksVariable (2–6 marks)