Biology

Meselson and Stahl's experiment eas based on the semi-conservative replication of the DNA. It means that when a parental DNA undergoes replication, each strand of the parental DNA serves as a template and the new daughter strand is synthesized on the template strand. Keeping the semi-conservative replication in view, and starting with DNA strands having N15​ and there after N14​, after the fourth generation there will be 0 strands having N15​ N15​, 2 strands having N15​ N14​ and 14 strands having  N14​  N14​. So the ratio comes out to be 0 : 1 : 7. so the correct option will be 'd'

4th ans.

4