CAIE A Level Biology 9700 · The mitotic cell cycle
A line of human cells is grown in culture and undergoes many rounds of cell division. After many divisions, scientists observe that the chromosomes have become shorter. Describe the structure of a chromosome and explain how telomeres protect the genetic information during repeated DNA replication.
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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