Question

If a hybrid DNA ($N^{14}{N}^{15}$) is allowed to replicate thrice in a medium containing $N^{14}$, then what is the proportion of light, heavy and hybrid DNA obtained, respectively?

Answer 1

The give question relates to Meselson and Stahl's experiment. If a hybrid DNA (N${}^{14}$N${}^{15}$) is allowed to replicate thrice in a medium containing N${}^{14}$, Meselson and Stahl found that in third generation 25% hybrid and 75% light DNA and no heavy DNA were obtained. So the proportion of light, heavy and hybrid DNA is found to be 3:0:1 respectively