two students decided to repeat the hershey and chase experiment, with modifications. like hershey and chase they used radioactive sulfur but they substituted radioactive nitrogen for radioactive phosphate. they reasoned that each nucleotide has only one phosphate and two to five nitrogen atoms. thus, labeling the nitrogen atoms would provide a stronger signal than labeling the phosphates. which of the following is the biggest shortcoming in their experimental design? answer with explanation @aibot
The biggest shortcoming in their experimental design is the assumption that labeling the nitrogen atoms would provide a stronger signal than labeling the phosphates. While it is true that nucleotides generally have more nitrogen atoms (two to five) compared to phosphates (one), it does not necessarily mean that the radioactive signal from nitrogen atoms would be stronger.
In the Hershey and Chase experiment, they used radioactive phosphorus (not phosphate) to label the DNA in the bacteriophage. This was because the DNA backbone contains phosphates and incorporating radioactive phosphorus into the DNA allowed them to track the transmission of genetic material.
By substituting radioactive nitrogen for radioactive phosphate, the students may not accurately capture the transmission and replication of genetic material. This is because nitrogen is also present in other cellular components such as proteins and nucleotide bases, making it difficult to distinguish the specific signal from DNA.
Therefore, the students’ experimental design fails to ensure that the radioactive signal they detect is exclusively from the DNA and may lead to inaccurate or inconclusive results.