what is meant by gene expression
Gene expression. Gene expression is the process by which the genetic code-the nucleotide sequence-of a gene is used to direct protein synthesis and produce the structures of the cell.Genes that code for amino acid sequences are known as 'structural genes'.The process of gene expression involves two main stages:Transcription: the production of messenger RNA (mRNA) by the enzyme RNA polymerase, and the processing of the resulting mRNA molecule.enes that code for amino acid sequences are known as 'structural genes'. The process of gene expression involves two main stages: Transcription: the production of messenger RNA (mRNA) by the enzyme RNA polymerase, and the processing of the resulting mRNA molecule.