CAIE A Level Biology 9700 · Nucleic acids and protein synthesis
A eukaryotic gene contains both introns and exons. The gene is transcribed to produce a primary transcript (pre-mRNA). Describe the modifications that occur to this primary transcript to form mature mRNA, and explain why these modifications are essential for the subsequent translation of the mRNA into a polypeptide.
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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