Question

Discuss the three theoretical models which describes structure of the DNA and describe the semi conservative replication of the DNA double helix structure. Furthermore, explain the differences between prokaryotic and eukaryotic DNA replication

Answer 1

Answer:

Three theoretical models for the replication of DNA had been proposed in the past. Out of these, the method of semi-conservative replication is most widely accepted.

Conservative replication: In this method, no DNA unwinding takes place. The parent DNA gives rise to daughter DNA.

Dispersive Method: In this method, the chains in the DNA molecule break and recombination occurs randomly. The daughter and parent strands will have segments of recombinant DNA.

Semi- conservative: In this method, the two strands of the double helix unwind. Each strand acts as a template for the synthesis of a new strand.

DNA replication is more complex in eukaryotes as compared to prokaryotes. Prokaryotes have a single point of origin from where the replication begins. Eukaryotes have multiple points of origin. Eukaryotic cells have a unidirectional method of replication whereas prokaryotes do not. Prokaryotes just have two polymerases whereas eukaryotes have more than four. The replication rate is faster in prokaryotes.