Why won't this experiment work? For a science fair project, two - ProProfs Discuss
Topics
Products
Follow Us:

Why won't this experiment work? For a science fair project, two students decided to repeat the  Hershey and Chase experiment, with modifications. They decided to label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogens. Thus, labeling the nitrogens would provide a stronger signal than labeling the phosphates.



A. There is no radioactive isotope of nitrogen.
B. Radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long.
C. Meselson and Stahl already did this experiment.
D. Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive.
E. Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.

This question is part of Chapter 16-17 Test - AP Biology
Asked by Muitran, Last updated: Feb 22, 2020

+ Answer
Request

2 Answers

Matz Lewis Clark

Traveler and writer by profession.

Matz Lewis Clark, College student, Graduation, Orlando

Answered Feb 28, 2019

The answer to this question is letter E. It should be noted that amino acids are also equipped with nitrogen atoms which means that it also contains proteins. The main goal of the experiment is to distinguish between the DNA and proteins but this is not possible if both of them have it.

The radioactivity will not be useful in checking what’s wrong. It is best if the two students would think of another project that may produce more productive results. It will also be advisable if they would also think of making other changes or modifications to the experiment that they want to re-do.

 

John Smith

John Smith

Answered Dec 19, 2016

Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.
 

Search for Google images
Select a recommended image
Upload from your computer
Search for Google images
Select a recommended image
Upload from your computer
Search for Google images
Select a recommended image
Upload from your computer

Email Sent
We have sent an email to your address "" with instructions to reset your password.