CBSE Class 10 Answered

Mam/Sir could you please explain the process of DNA copying?

Asked by Paraukkhal | 10 Feb, 2011, 06:52: PM

Expert Answer

Dear student,

DNA copying or replication is the process by which two copies of a DNA molecule is produced from one.

Since the two strands of a DNA molecule have complementary base pairs, the nucleotide sequence of each strand automatically supplies the information needed to produce its partner. If the two strands of a DNA molecule are separated, each can be used as a template to produce a complementary strand. Each template and its new complement together then form a new DNA double helix, identical to the original.

Before replication can occur, the length of the DNA double helix about to be copied must be unwound. In addition, the two strands must be separated by breaking the weak hydrogen bonds that link the paired bases. Once the DNA strands have been unwound, they must be held apart to expose the bases so that new nucleotide partners can hydrogen-bond to them.
The enzyme DNA polymerase then moves along the exposed DNA strand, joining newly arrived nucleotides into a new DNA strand that is complementary to the template. Each cell contains a family of more than thirty enzymes to ensure the accurate replication of DNA.

Regards, Team Topperlearning

Answered by | 12 Feb, 2011, 12:53: AM