CAIE A Level Biology 9700 · Nucleic acids and protein synthesis
In eukaryotic cells, a gene's primary transcript (pre-mRNA) contains both introns and exons. Describe the process by which the primary transcript is modified to produce mature mRNA, and explain why this modification is necessary for polypeptide synthesis.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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