Question

What is DNA copying? State its importance.

Answer 1

Hint: Meiosis creates a copy of DNA in each gamete during gametogenesis. The copying follows crossing over, linkage and recombination during gametogenesis to create new variations.

Complete answer:
Complete step by step answer:
DNA copying is a process where a molecule of DNA makes its identical copies of itself inside a gamete (reproductive cell). It takes place through the process of DNA replication. In this process on both strands of DNA a new strand is synthesised. So due to the synthesis of this new strand, the DNA replication process is considered Semi conservative in nature. It was proposed by Watson & Crick but proved by Meselson & Stahl. The process completes in three steps:
> Initiation
> Elongation
> Termination.
The whole process is incomplete without the enzymes. So, for completion, they require enzymes and the most important enzyme of this process is DNA-dependent polymerase.
Importance:
> With the help of this process, variations are easily created for the offspring.
> Inheritance of variations is made through this process.
> When this variation is caused on a large scale it assimilates easily in a population and supports the survival of the fittest with certain adaptations due to the advantage of variations.

Note:
DNA copying is the process by which DNA makes a copy of itself during cell division. Steps are:
Step 1- “Unzip DNA helix”.
Helicase enzymes carry out this unzip process.
Step 2- Replication fork is made & the two separated strands act as templates for making the new strands of DNA.
The strands are oriented in the 3’ to 5’ direction i.e. towards the replication fork, is the Leading strand. The strand oriented in the 5’ to 3’ direction is the lagging strand.
On leading, strand DNA replication is a continuous process.
On the Lagging strand, the DNA replication is discontinuous, takes place with the help of formation of a structure called Okazaki fragments which are later joined as one using a Ligase enzyme.