Final answer:
Aldosterone uses direct gene activation to regulate gene expression without involving G proteins or second messengers like cAMP.
Step-by-step explanation:
Aldosterone uses direct gene activation to exert its biological effects. Being a steroid hormone, aldosterone enters cells and binds to intracellular receptors. These receptors then interact with DNA at specific hormone response elements to alter gene expression. This process does not involve G proteins or second messengers such as cAMP, which are typical of peptide hormone signaling pathways.