Replication was allowed to take place in the presence of redioactive deoxynucleotides precursors in E. coli that was a mutant for DNA ligase. Nswly synthesised redioactive DNA was purified and strands were separated by denatureation. These were centrifuged using density gradient centrifugation. Which of the following would be a correct resulat ?

Explanation

In above case, as E. coli is a mutant for DNA ligase, it will result in no further joining of Okazaki fragments on lagging strand.
This will ultimately result into the formation of both high molecular weight fragments (on leading strands) and low molecular weight fragments (on lagging strand). Hence, only the graph (a) could be th e appropriate result centrifugation .