Biology 9700 · AS & A Level · Principles of genetic technology
Principles of genetic technology — practice question
In 1984, the geneticist Alec Jeffreys developed a DNA testing method called DNA profiling, which creates a DNA banding pattern on a gel. This banding pattern, or profile, is different for every individual. DNA profiling is used in police forensic work to identify criminals. Since 1987, police in many countries have gathered and stored DNA from crime scenes to build DNA profiles, then compared these with the DNA profiles of criminal suspects.
(a(i))[2]
Explain why PCR may be needed before crime-scene DNA is profiled.
(a(ii))[2]
Explain why electrophoresis leads to a DNA banding pattern on a gel.
(b(i))[2]
Suggest why the police approach of comparing crime-scene DNA against the GEDmatch database worked so successfully.
(b(ii))[2]
Explain why GEDmatch can be described as an example of bioinformatics.
(b(iii))[2]
Comment on the social and ethical issues arising from this first successful conviction.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Crime-scene DNA may exist in very small amounts” …