AP BIOLOGY

Detailed explanation-1: -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-2: -Mitogens stimulate the rate of cell division by removing intracellular molecular brakes that restrain cell-cycle progression in G1. Growth factors promote an increase in cell mass by stimulating the synthesis and inhibiting the degradation of macromolecules.

Detailed explanation-3: -Growth Factor Signaling Transduction Growth factors, which generally considered as a subset of cytokines, refer to the diffusible signaling proteins that stimulate cell growth, differentiation, survival, inflammation, and tissue repair.

Detailed explanation-4: -When proteins synthesized by one cell can diffuse over small distances to induce changes in neighboring cells, the event is called a paracrine interaction, and the diffusible proteins are called paracrine factors or growth and differentiation factors (GDFs).