Answer the following questions based on Meselson and Stahl's experiment : <br>
a. Write the name of the chemical substance used as a source of nitrogen in the experiment by them. <br>
b. Why did the scientists synthesize the light and the heavy DNA molecules in the organism in
the experiment? <br>
c. How did the scientists make it possible to distinguish the heavy DNA molecule from the
light DNA molecule? Explain. <br>
d. Write the conclusion the scientists arrived at, after completing the experiment.