What meaning is associated with the root word "estro-"?

The root word "estro-" is derived from the Greek word "estrus," which refers to the period of sexual receptivity in female mammals. This term is commonly associated with female reproductive cycles. In medical terminology, it often relates to hormones such as estrogen, which play crucial roles in female development and reproductive health. Therefore, the meaning connected to "estro-" is specifically indicative of females and their reproductive biology.

The other choices do not accurately align with the meaning of "estro-," as they pertain to different concepts that do not relate to the female reproductive aspect evoked by the root word.