What does gene expression refer to?

Gene expression refers to the process by which information from a gene is used to synthesize functional gene products, typically proteins, that affect the cell's structure and function. This process involves transcription, where the DNA sequence of a gene is transcribed to produce RNA, followed by translation, where the RNA is used to assemble protein molecules based on the genetic code.

The notion of gene expression as the combination of genes expressed in organisms is particularly significant because it encapsulates the dynamic nature of how genes can be activated or silenced in response to various cellular or environmental signals. In different cell types or under different conditions, a specific subset of genes is expressed to fulfill distinct functional roles, which is essential for growth, development, and response to environmental changes.

Understanding gene expression is fundamental in the fields of genetics and molecular biology, as it plays a crucial role in determining phenotypes and understanding diseases, such as cancer, where gene expression can be altered. Therefore, defining gene expression through the lens of the combination of genes expressed in organisms emphasizes its pivotal role in shaping biological functions and characteristics.