Class 12 Biology Molecular Basis of Inheritance DNA Replication

DNA Replication

Replication is the process of reproducing or creating a copy of something. In this topic, we will see how DNA creates a copy of itself.

Various hypotheses were proposed by various scientists regarding the replication model of DNA i.e. how DNA replicates. Some of these were:

  • Semi-conservative DNA replication model
  • Conservative DNA replication
  • Dispersive DNA replication

 

Semi-conservative DNA replication model

Watson & Crick suggested the ‘Semi conservative DNA replication’ model. According to this model, the two strands of DNA separate.

Each strand act as template for synthesis of a new strand. The new strand is synthesized based on complementary base pairing with the template.

Each new DNA molecule has 1 parental strand & 1 one newly formed strand. This is how the original DNA molecule (1 copy) gives rise to two copies.

Class_12_Molecular_Basis_Of_Inheritance_SemiConservative_DNA_Model

Conservative DNA replication

According to this model, Complete DNA molecule (and not just one strand) acts as a template for new synthesis.

Class_12_Molecular_Basis_Of_Inheritance_Conservative_DNA_Model

Dispersive DNA replication

According to the Dispersive model, the new DNA is synthesized in short pieces. A part of the old strand is attached to the end of a part of newly synthesized strand.

Class_12_Molecular_Basis_Of_Inheritance_Dispersive_DNA_Replication

Share these Notes with your friends  

< Prev Next >

You can check our 5-step learning process


.