$DNA$ replication in bacteria occurs

The mode of $DNA$ replication is .....

Which enzyme catalyzes the process of reverse transcription?

$DNA$-dependent $DNA$ polymerase catalyzes polymerization in which direction?

Replication was allowed to take place in the presence of radioactive deoxynucleotide precursors in $E. coli$ that was a mutant for $DNA$ ligase. Newly synthesised radioactive $DNA$ was purified and strands were separated by denaturation. These were centrifuged using density gradient centrifugation. Which of the following would be a correct result?

At the end of $DNA$ replication,the $DNA$ molecule has: