Final answer:
Different cell types may respond differently to the same hormone due to variation in receptors and gene expression. Hormones act by binding to specific receptors on cells, influencing gene expression and resulting in various cellular responses. The sensitivity of cells to hormones is regulated by the number of available receptors and can be altered through up-regulation or down-regulation.
Step-by-step explanation:
Even though different cell types may respond to the same hormone, they do not necessarily turn on the same sets of genes. This is because each type of cell contains different genes which produce different receptors or the same receptor with different signaling components. When a hormone, acting as a ligand, binds to these receptors, it can activate a variety of responses depending on the cell type. These responses can range from stimulation of protein synthesis to changes in cell permeability or mitosis rates.
Hormones alter conditions inside cells by binding to hormone receptors, which act as transcription regulators. This leads to changes in gene expression. Whether a hormone's effect is turned on or off depends on the presence or absence of a stimulus that regulates the hormone's action. Additionally, the sensitivity of a cell to a hormone is determined by the number of receptors on its surface, which can undergo up-regulation or down-regulation.