Answer:
6. Because of how old the rocks are
Explanation:
6. Sedimentary rock forms in layers because of the order they were formed. The older rocks will form first and as time goes on, rock forms above it to create a new layer, and so on.
Breaking cells open to release the DNA.
Separating DNA from proteins and other cellular debris.
Precipitating the DNA with an alcohol.
Cleaning the DNA.
Confirming the presence and quality of the DNA.
Her conclusion is invalid because using sand instead of soil slows down plant growth. Fertilizer, on its own, does not 'greatly' increase the size of the plant.
The correct way to do this experiment would be to keep all other parameters same, except the fertilizer. This will give her accurate results.
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