Question

Why is DNA replication bidirectional ?

Answer 1

Bidirectional DNA replication:

1. DNA replication is the process of making new copies of double-stranded DNA by synthesizing new DNA strands.
2. DNA replication is a bidirectional process as the strands of DNA are antiparallel, i.e., 3'-5' in one strand and 5'-3' in the other direction.
3. The DNA polymerase synthesizes the DNA in 5'-3' direction.
4. Hence, on the template strand the synthesis occurs in 5'-3' direction continuously whereas in the non-template strand it occurs discontinuously in 3'-5' direction creating small fragments of DNA known as Okazaki fragments.
5. Thus, bidirectional replication involves replicating DNA in two directions at the same time which results in a leading strand and a lagging strand.
6. DNA replication can occur in a unidirectional or bidirectional fashion.
7. When the replication occurs bidirectionally, none of the two ends will be stationary and both will be moving.