AP BIOLOGY

Detailed explanation-1: -Juxtacrine signaling occurs between neighboring cells that are in physical contact with each other. In this case, the signaling molecule is not free, but is instead bound to the membrane of the cell. It may then interact with a receptor on the membrane of an adjacent cell.

Detailed explanation-2: -Paracrine signaling Often, cells that are near one another communicate through the release of chemical messengers (ligands that can diffuse through the space between the cells). This type of signaling, in which cells communicate over relatively short distances, is known as paracrine signaling.

Detailed explanation-3: -Direct signaling (also called juxtacrine signaling) involves communication between cells that are in direct contact with each other. This communication is often mediated by gap junctions in animal cells and plasmodesmata in plant cells.

Detailed explanation-4: -Endocrine Signaling These types of signals usually produce a slower response but have a longer-lasting effect. The ligands released in endocrine signaling are called hormones, signaling molecules that are produced in one part of the body but affect other body regions some distance away.

Detailed explanation-5: -A signal is detected when the chemical signal (also known as a ligand) binds to a receptor protein on the surface of the cell or inside the cell. 2. Transduction: When the signaling molecule binds the receptor it changes the receptor protein in some way. This change initiates the process of transduction.