What does gene expression refer to?

Gene expression refers to the process by which information from a gene is used to synthesize a functional gene product, typically proteins. This process involves two key stages: transcription and translation. During transcription, the DNA sequence of a gene is transcribed to produce messenger RNA (mRNA). After this, during translation, the mRNA is used as a template to build a specific protein through the assembly of amino acids in the correct order specified by the mRNA.

This means that gene expression encompasses the entire flow of information from the genetic code in the DNA, through the creation of mRNA, and ultimately resulting in the formation of proteins. This is fundamental to numerous biological processes, as proteins perform critical functions within the cell and organism, including acting as enzymes, structural components, signaling molecules, and more.

The other choices refer to different concepts that do not encapsulate the full process of gene expression. For example, mutations in DNA do not directly explain how genes are expressed; instead, they can affect expression. The replication of DNA pertains to how the genetic material is copied, rather than how it is expressed. Lastly, transcription of RNA represents only the first step of gene expression but does not include the subsequent translation into proteins. Thus, the correct understanding of