Biology 2nd Edition by Robert Brooker, Eric Widmaier ,Linda Graham ,Peter Stiling

تمرين 6

Meselson and Stahl were able to demonstrate semiconservative replication in E. coli by
A) using radioactive isotopes of phosphorus to label the old strand and visually determining the relationship of old and new DNA strands.
B) using different enzymes to eliminate old strands from DNA.
C) using isotopes of nitrogen to label the DNA and determining the relationship of old and new DNA strands by density differences of the new molecules.
D) labeling viral DNA before it was incorporated into a bacterial cell and visually determining the location of the DNA after centrifugation.