NEET BIOLOGY

Detailed explanation-1: -In addition to mitogens that stimulate cell division, there are factors, such as some members of the transforming growth factor- (TGF-) family, that act on some cells to stimulate cell proliferation and others to inhibit it, or that stimulate at one concentration and inhibit at another.

Detailed explanation-2: -Usually it is a secreted protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes. Growth factors typically act as signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptors on the surface of their target cells.

Detailed explanation-3: -Growth factors (GFs) are a group of proteins stimulating the growth of specific tissues. GF plays important roles in the regulation of cell division that drives cell proliferation. Each GF binds to a specific cell–surface receptor.

Detailed explanation-4: -Examples of protein growth factors are vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF). Growth factor specificity to particular cell types is achievable by the expression of highly specific cell surface receptors.