Question

Mention the main steps in DNA replication.

Answer 1

Answer:

Main steps of DNA replication are;

Step 1: Unwinding of the DNA

Here the enzyme DNA helicase breaks the hydrogen bonding between the nucleotide base pairs forming a fork-like structure which is called as replication fork, thus unwinding the DNA. Now, we have two DNA strands one leading and one lagging.

Step 2: Elongation

Here in the leading strand DNA polymerase forms the new strand. While in the lagging strand primase enzyme forms mini stretches of RNA primers called 'Okazaki fragment' which is then after the elongation of the leading strand the DNA polymerase will then convert those Okazaki fragments into DNA strands.

Step 3: Termination

Now after the completion of the new DNA strand synthesis the DNA polymerase enzyme terminates the process and the enzyme DNA ligase ligates the fragments forming a complete strand.

Step 4: Proofreading

In this step, the DNA polymerase enzyme completely proofreads the newly formed DNA strand for any mistakes.

Answer 2

Explanation:

double standard DNA molecules unwids with the help of certain enzymes to express two standard of DNA

ii) a DNA polymerase enzymes catalyzes the formation of a new daughter strand which can form a double helix with one stand of parental DNA molecules two DNA molecules.

iii) the two identical DNA molecules them become two chromatids which remain attached by a centromere

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