<prompt> Which of the following is not seen in humansEstrous CycleMenstrual CycleEndometrial cycleOvarian Cycle  <response>: Ans a Estrous CycleRef: Ganong, 25th edp.403Estrous Cycle is seen in animals.It has three phases namely,Proestrus - ovarian follicle enlargesEstrus - period of sexual receptivityMetestrus - postovulatory phaseDiestrus - a short period of inactivity before next proestrus 