Final answer:
Type II nuclear receptors (NR) are activated by hormones and ligands, such as estrogens, thyroid hormone (T3), and retinoids. These receptors act as transcription factors and bind to specific DNA sequences called hormone response elements (HREs) to regulate gene expression and mediate changes in cell function.
Step-by-step explanation:
Type II nuclear receptors (NR) are activated by various hormones and ligands. For example, estrogen receptors are activated by estrogens, thyroid hormone receptors are activated by the thyroid hormone (T3), and peroxisome proliferator-activated receptors (PPARs) are activated by retinoids and fatty acids. These receptors function as hormone-activated transcription factors and bind to specific DNA sequences called hormone response elements (HREs) to trigger gene transcription and translation, resulting in changes in cell function.