Here's why:

* Genes are segments of DNA: They carry the genetic code, which is a set of instructions for building and maintaining an organism.

* DNA codes for proteins: The sequence of nucleotides in a gene dictates the sequence of amino acids in a protein.

* Proteins are the workhorses of the cell: They perform a vast array of functions, including:

* Enzymes: Catalyze biochemical reactions.

* Structural components: Provide support and shape to cells and tissues.

* Hormones: Act as chemical messengers.

* Antibodies: Defend against pathogens.

* Transporters: Move molecules across cell membranes.

So, a gene's instructions are ultimately translated into a protein, which then carries out a specific function within the organism.