Question

For each statement, choose which strand, if any, fits the description of the diagram relative to the right side of the origin of replication.

strand A 5' 3' strand B ori

1- Producing an identical copy of this strand involves a single primer molecule.................   ["neither strand", "strand A", "strand B", or "both strands"]      

2- Producing an identical copy of this strand involves multiple primer molecules................. ["neither strand", "strand B", "both strands", or "strand A"]      

3- This is the template for the leading strand synthesis.................... ["strand B", "both strands", "strand A", or "neither strand"]

4- The regular DNA replication machinery of the cell can not prevent the shortening of this strand during successive replication cycles.................... [ "strand B", or "strand A]

Answer 1

1. Neither strand can be used to produce an identical copy of this strand involving a single primer molecule because during the replication process the complementary strand gets replicated at the desired strand and not the identical copy of the desired strand, either by using a single or multiple primer molecule.
2. Neither strand can be used to produce an identical copy of this strand involving a single primer molecule because during the replication process the complementary strand gets replicated at the desired strand and not the identical copy of the desired strand, either by using a single or multiple primer molecule.
3. The template for leading strand synthesis would be “strand A” as the replication begins at ori region of DNA and the leading strand is replicated continuously in 3’ to 5’ direction.
4. The regular DNA replication machinery of the cell can not prevent the shortening of this “strand A” during successive replication cycles as the replication machinery and primer need some bases to sit and start the replication process. Once, the polymerase sits on the DNA, it doesn’t replicate the section of DNA where it sits, therefore, the strand shortens at successive replication.