Final answer:
Signals are typically conveyed to a target cell's interior by binding to specific cell surface receptors, which trigger signal transduction to transmit the signal inside the cell.
Step-by-step explanation:
The signal is typically conveyed into the target interior by binding to specific membrane receptors. These receptors are located on the surface of the cell and interact with water-soluble hydrophilic ligands that cannot diffuse through the cell membrane. Upon ligand binding, this triggers a series of reactions known as signal transduction, which transmits the signal into the cytoplasm of the cell and can lead to various cellular responses, including the transcription and translation of specific genes. Hydrophobic ligands, however, can directly pass through the plasma membrane and bind to internal receptors. These ligand-receptor complexes can then move to the nucleus to interact directly with DNA and initiate protein synthesis.