Testosterone Is One, So Is Estrogen

This page is the CodyCross answer for the clue below from Physics, Group 1897, Puzzle 5 (Harmonic Oscillator).

Question is: Testosterone Is One, So Is Estrogen

and the answer is: HORMONE

Word Meaning:

HORMONE — (physiology) Any substance produced by one tissue and conveyed by the bloodstream to another to effect physiological activity.

Definitions from Wiktionary.