3) Two students decided to repeat the Hershey and Chase experiment, with modifications for a science competition. They radioactively tag the nitrogen of the DNA, rather than the phosphate. Each nucleotide has only one phosphate and two to five nitrogen atoms, the strategy of labeling the nitrogen atoms would detect a stronger signal than labeling the phosphates. Why won't this approach work

Explanation:

In the Hershey and Chase experiment, they aimed to show where the phage DNA went when it exited the protein coat and entered the bacteria. In this scenario, the two student's approach won't work because amino acids (and therefore all proteins) also have nitrogen atoms which ultimately means that the radioactivity would not distinguish between DNA and proteins and the experiment will not provide the correct results.

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the fossil record provides evidence of a common ancestor to many species.