CAIE A Level Biology 9700 · Nucleic acids and protein synthesis
The table shows the percentages of the four bases in a sample of double-stranded DNA isolated from a bacterium.
| Base | Percentage (%) |
|---|---|
| A | 28 |
| T | 28 |
| C | 22 |
| G | 22 |
Describe the structure of DNA and explain how these data support the current understanding of DNA structure.
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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