Hormones are intercellular chemical signals that

A) are secreted into the external environment where they act.
B) affect only non-hormone producing organs or tissues.
C) help coordinate growth, development and reproduction.
D) operate primarily by positive feedback.

Intercellular Signals

Chemical or physical messages passed between cells to coordinate their activities and functions within an organism.

Coordinate Growth

The process by which various parts of an organism grow at rates that maintain the overall shape and proportion of the organism.