OCR A Level Manipulating Genomes

Image: Rainis Venta, via Wikimedia Commons

I’ve worked with many students studying OCR A Level biology, and this is a topic that often causes confusion. It can feel like a collection of separate ideas, and students often struggle to understand how the sections hang together. Additional confusion can then come from the differences between the classic techniques (e.g. for gel electrophoresis and DNA profiling) that are examined by OCR and the modern versions of these techniques that may come up during an internet search.

This summary covers the bare essentials required by OCR for the topics I get asked about most. Methods and applications are kept separate, and colour coding shows where techniques overlap.

What this resource covers

This resource covers the following parts of the OCR A Level specification:

6.1.3 Manipulating genomes

(a) the principles of DNA sequencing and new DNA sequencing techniques
(b)(i) how gene sequencing has allowed for genome-wide comparisons between individuals and between species
(b)(ii) how gene sequencing has allowed for the sequences of amino acids in polypeptides to be predicted
(b)(iii) how gene sequencing has allowed for the development of synthetic biology
(c‌) the principles of DNA profiling and its uses
(d) the principles of the polymerase chain reaction (PCR) and its application in DNA analysis
(e) the principles and uses of electrophoresis for separating nucleic acid fragments or proteins
(f)(i) the principles of genetic engineering
(f)(ii) the techniques used in genetic engineering