In the meselson-stahl experiment, cells were grown for one generation in growth medium containing a relatively heavy nitrogen isotope, then transferred to new medium containing a lighter nitrogen isotope. after another round of cell division, what is true of the dna in the cells?
answer
a. all dna contains only the lighter nitrogen isotope.
b. half of the dna contains only the light nitrogen isotope.
c. all dna contains only the heavy nitrogen isotope.
d. all dna contains a hybrid of heavy and light nitrogen isotopes