Hormones are chemical substances that help to regulate processes in the body. Hormones are secreted by glands and travel to their target organs in the bloodstream. Hormones can be used to control human fertility.
Fossil evidence because these changed occur over long time periods (millions of years).
<span>1) maintenance of body homeostasis by regulation and coordination of all organ systems.
2) Acts as the sensor and control center for many systems
3) provides communication between the control center sensors and effectors.
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Homeostasis and transport of molecules
