Chemical substances secreted by cells into the extracellular fluids that regulate the metabolic function of other cells in the body are called

a. antibodies
b. hormones
c. proteins
d. enzymes

hormones

Explanation:hormones are chemical molecules which serves to control the function and activities of various body systems.they move from where they are produced through the blood stream,to where they are supposed to act.hormones act by chemically binding to specific receptors on the cell . Once the hormone binds to the receptor, a chain of events is initiated that leads to the target cell’s response. . These responses contribute to human reproduction, growth and development of body tissues, metabolism, fluid, and electrolytes and control other body functions even when in low concentration

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.