Question

why is the 3’ to 5’ strand known as the “lagging strand?” polymerase leaves this strand fragmented because it doesn’t directly build in the 3’ to 5’ direction because primase can only bond to the 3’ to 5’ strand, leaving fragments because helicase only unzips dna strands in one direction, 5’ to 3’

Explanation:

DNA polymerase synthesizes DNA in the 5' to 3' direction. On the 3' to 5' template strand, DNA is synthesized in short, discontinuous fragments (Okazaki fragments) because the polymerase has to work in the opposite direction to the replication - fork movement. This causes the synthesis on this strand to be slower or 'lagging' compared to the leading strand where synthesis is continuous.

Answer:

A. Polymerase leaves this strand fragmented because it doesn't directly build in the 3’ to 5’ direction