A-Level BiologyYear 2017Q1
Page 02 SECTION 1 — 25 marks Attempt ALL questions 1. Trypan blue is used as a vital stain to identify viable cells when viewed in a haemocytometer. A vital stain A stains all cells B only stains dead cells C only stains living cells D only stains the culture medium. 2. Bovine insulin is a soluble protein with an isoelectric point of pH 5·4. Which of the following graphs represents the level of precipitate formed as the pH of a bovine insulin solution is changed? 9 9 9 9 1 1 1 1 pH pH pH pH mass of precipitate (mg) mass of precipitate (mg) mass of precipitate (mg) mass of precipitate (mg) C A B D
Paper Source:NAH_Biology_all_2017.pdf
Get full Socratic AI guidance on this question — free in the Applaa desktop app
Appy Buddy guides you step-by-step toward the answer without giving it away. Type your attempt and get instant, mark-scheme-aware clues that teach you to think like an examiner.
Applaa Desktop App
Join Applaa Community
Create your own games, learn AI concepts, program interactive apps, and share with a kid-safe community approved by parents. Free forever on Windows and Mac.
Download Free
Available for Windows and macOS · COPPA Compliant
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)