Final answer:
Steroid hormones exert their action by binding to intracellular receptors in target cells and initiating or enhancing the synthesis of proteins.
Step-by-step explanation:
Steroid hormones exert their action by binding to intracellular receptors residing in the cytoplasm or nucleus of a target cell. Once the hormone binds to its receptor, it forms a hormone-receptor complex that moves toward the chromatin in the cell nucleus. This complex then binds to a specific site on DNA and initiates or enhances the synthesis of mRNA, leading to the production of proteins and increasing or decreasing specific cell processes.