During gene expression, what is the product of transcription?

Transcription is the process by which the information in a gene is transcribed from DNA to a complementary RNA molecule. The primary product of this process is messenger RNA (mRNA). During transcription, an enzyme called RNA polymerase synthesizes the mRNA strand by reading the DNA template and building an RNA molecule that reflects the sequence of nucleotides in the DNA. This mRNA then carries the genetic information from the nucleus, where it is synthesized, to the ribosomes in the cytoplasm, which is the site of protein synthesis.

While other forms of RNA, such as ribosomal RNA (rRNA) and transfer RNA (tRNA), are also important for gene expression and protein synthesis, they are transcribed from DNA but are not the direct product of the transcription process regarding a specific gene's instructions. In conclusion, mRNA is the essential product of transcription as it encodes the information necessary to produce proteins, which are vital for numerous cellular functions.