Which best describes the purpose of gene expression?

The purpose of gene expression is best described as the process by which genetic information from a gene is used to produce a functional gene product, primarily proteins. This process consists of two main stages: transcription, where the DNA sequence of a gene is transcribed into messenger RNA (mRNA), and translation, where the mRNA is translated into a specific sequence of amino acids, ultimately folding into a functional protein.

Producing proteins is vital for carrying out various functions in the cell, including catalyzing biochemical reactions, providing structure, signaling, and regulating biological processes. Thus, gene expression is fundamental to the functioning of cells and the organism as a whole.

In contrast, replicating genetic material pertains to DNA replication, which occurs during cell division, and is not a function of gene expression. Breaking down excess nucleotides relates to nucleotide metabolism, which is not directly tied to the concept of gene expression. Repairing damaged DNA involves processes that maintain genomic integrity but do not directly relate to the synthesis of gene products. Understanding gene expression and its central role in biology is crucial for grasping how traits are inherited and how organisms adapt to their environment.