Edexcel A Level Biology A (Salters-Nuffield)
Edexcel A Level Biology A (Salters-Nuffield) Topic 6: Forensics Exam Questions
Free Edexcel A Level Biology A (Salters-Nuffield) exam questions on Topic 6: Forensics, with mark schemes. Covers DNA profiling, PCR, gel electrophoresis and determining time of death.
Topic 6: Forensics exam questions
These packs of real past exam questions cover the whole of Topic 6: Immunity, Infection and Forensics, including Topic 6: Forensics. Work through every question on this sub-topic, then mark your answers against the mark scheme.
StemUp mark scheme flashcards
Edexcel A Level Biology A (SNAB) 9BN0 Flashcards (Anki & Quizlet)
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Use them on Anki or Quizlet, then test yourself with the questions on this page.
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About Edexcel A Level Biology A (Salters-Nuffield) Topic 6: Forensics
This part of Topic 6 explains how biology solves crimes. Expect questions on the steps of DNA profiling and estimating time of death.
What you need to know
- DNA profiling Uses short tandem repeats, PCR to amplify DNA and gel electrophoresis to separate fragments.
- PCR Denaturing, annealing primers and extension by Taq polymerase, repeated many cycles.
- Time of death Body temperature, rigor mortis, decomposition, forensic entomology and succession.
- Uses Identifying suspects, paternity testing and identifying remains.
Common mistakes in Topic 6: Forensics
- Saying gel electrophoresis separates by charge only (it is by size).
- Missing the role of Taq polymerase.
- Confusing rigor mortis timing.
Try three Topic 6: Forensics exam-style questions
1. Describe the purpose of PCR in DNA profiling. (2 marks)
Show the mark scheme answer
It amplifies small samples of DNA (1), making millions of copies for analysis (1).
2. Explain how gel electrophoresis separates DNA fragments. (2 marks)
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DNA is negatively charged so it moves towards the positive electrode (1); smaller fragments move further through the gel (1).
3. Explain how body temperature can be used to estimate time of death. (2 marks)
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The body cools at a roughly predictable rate after death (1), so the temperature indicates how long ago death occurred (1).
Topic 6: Forensics FAQs
What does this part of SNAB Topic 6 cover?
DNA profiling, PCR, electrophoresis and estimating time of death.
Which paper tests Topic 6?
Papers 2 and 3.
Do I need the PCR temperatures?
Know the three stages and the purpose of each temperature.
Revise this topic with flashcards: Edexcel A Level Biology A (SNAB) 9BN0 Flashcards, with mark scheme answers for Anki and Quizlet.
