AP BIOLOGY

Detailed explanation-1: -Endocrine signaling: a cell targets a distant cell through the bloodstream. A signaling molecule is released by one cell, then travels through the bloodstream to bind to receptors on a distant target cell elsewhere in the body.

Detailed explanation-2: -In endocrine signaling, the signaling molecules (hormones) are secreted by specialized endocrine cells and carried through the circulation to act on target cells at distant body sites.

Detailed explanation-3: -Depending on the ligand’s origin (from the same cell, from the neighbour cell or from far distance), recptor-ligand interaction and signaling pathway activation is classified into four different types: autocrine, endocrine, paracrine and juxtacrine.

Detailed explanation-4: -Paracrine signaling acts on nearby cells, endocrine signaling uses the circulatory system to transport ligands, and autocrine signaling acts on the signaling cell. Signaling via gap junctions involves signaling molecules moving directly between adjacent cells. responses that last only a short amount of time.

Detailed explanation-5: -Define autocrine signaling: It refers to self-targeting, i.e., the cell signals produced by the cells bind to the receptors of the same cells. Define paracrine signaling: Paracrine signaling is between cells that are closely associated or in the vicinity.