Question

What happens during gene expression

Answer 1

Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA (rRNA), transfer RNA (tRNA) or small nuclear RNA (snRNA) genes, the product is a functional RNA.
A shorter version: Genes are expressed by being transcribed into RNA, and this transcript may then be translated into protein.
http://en.wikipedia.org/wiki/Gene_expression