What is a primary sexual characteristic in females?

A primary sexual characteristic in females refers to the anatomical structures that are directly involved in reproduction and are present at birth. The development of female reproductive organs, such as the ovaries, fallopian tubes, uterus, and vagina, is a key aspect of primary sexual characteristics. These organs are essential for the functions of reproduction, including ovulation, fertilization, and gestation.

In contrast, menstrual cycle regulation, breast development, and changes in voice pitch are secondary sexual characteristics or functions that emerge later in life due to hormonal changes, primarily during puberty. While they are indeed important aspects of female sexual development, they do not constitute primary sexual characteristics since they do not involve the intrinsic reproductive structures themselves.