CAIE A Level Biology 9700 · Nucleic acids and protein synthesis
The table shows the percentage of each nitrogenous base in a sample of DNA from a fungal species.
| Base | Percentage |
|---|---|
| Adenine | 31.0 |
| Thymine | 31.0 |
| Guanine | 19.0 |
| Cytosine | 19.0 |
Describe the structure of DNA, using the base composition data in the table to support your description.
4 marks, so the mark scheme is looking for about 4 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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