Question

How does transcription differ from DNA replication?

Answer 1

Deoxyribonucleic acid (DNA) is a molecule that contains the genetic information that is important for the development, functioning, reproduction, and growth of all organisms. It is composed of two polynucleotide chains that form a double-helix structure.

Complete answer:
Two important steps associated with DNA are its replication and transcription. DNA replication is the process of splitting of DNA to form two daughter strands in which each daughter contains half of the parental DNA. This is the reason that each daughter cell formed during cell division contains the same genetic information as that of their parent cells. It occurs during the S phase of the cell cycle. Some important enzymes that help in DNA replication are DNA polymerase and DNA helicase. DNA polymerase adds nucleotides to each strand. For replication to occur, a small strand of DNA known as the primer is required.
On the other hand, transcription is the process of transferring genetic information from DNA to RNA (ribonucleic acid). It occurs during the G1 and G2 phases of the cell cycle. The enzymes used as the catalyst for this reaction are RNA polymerase and transcriptase. No primer is required in transcription. Unlike replication, only one DNA strand is used for transcription because if both the strands would be used, it would create difficulty in understanding which one code should be followed. The strand which is used for transcription is known as the template strand. A complementary RNA molecule (transcript) is synthesized from the template strand.

Note: Both the processes, DNA replication, and transcription produce a new copy of DNA in a cell. DNA transcription involves replicating DNA into RNA while replication produces another copy of DNA. Thus, we can say that in both the processes new nucleic acids (either DNA or RNA) are formed.