Which enzyme is responsible for synthesizing mRNA during transcription?

The enzyme responsible for synthesizing mRNA during transcription is RNA polymerase. This enzyme plays a crucial role in the process of transcription, where it unwinds the DNA double helix and synthesizes a complementary strand of RNA based on the DNA template.

During transcription, RNA polymerase binds to a specific region of the DNA called the promoter. It then proceeds down the DNA strand, synthesizing mRNA by adding ribonucleotides that are complementary to the DNA template strand. This newly synthesized mRNA can then be processed and translated into proteins.

The other enzymes listed serve different functions within cellular processes. DNA polymerase is involved in DNA replication, where it synthesizes a new DNA strand. Ligase is responsible for joining Okazaki fragments on the lagging strand during DNA replication. Restriction enzymes, on the other hand, are used in molecular biology to cut DNA at specific sequences for cloning or analysis purposes. Thus, their functions do not relate to the synthesis of mRNA.