Final answer:
If the signal molecule acts on the cell that secreted it, the chemical is called an autocrine ligand. Autocrine ligands are signaling molecules that are released by a cell and bind to receptors on the same cell, eliciting a response.
Step-by-step explanation:
If the signal molecule acts on the cell that secreted it, the chemical is called a autocrine ligand. Autocrine ligands are signaling molecules that are released by a cell and bind to receptors on the same cell, eliciting a response. This type of signaling is characterized by self-stimulation and is involved in various physiological processes.