The youngest female documented to have given birth to a healthy child was a 5-year-old girl in the 1930s; the father was never identified. She began having regular menstrual periods around eight months of age. She was diagnosed as pregnant after being taken to a doctor for suspicion of having an abdominal tumor; her periods had ceased several months earlier and her breasts were well-developed.

Question

When do the reproductive organs normally develop? Describe the maturation her body underwent to render her fertile, specifying at what ages these changes normally take place. Even without a positive pregnancy test, what clues suggest pregnancy rather than a tumor? What is the earliest age at which gamete development normally begins and ends in both genders?

What will be an ideal response?

Answer 1

Internal reproductive organs are present as early as six weeks after fertilization. The reproductive organs are
gender-distinct by 10 weeks. To be fertile means to have mature reproductive organs and active hormonal control
of a menstrual cycle. Final sexual maturation resumes at puberty as hormone production increases, normally
between ages 8 and 14. These changes include the onset of menses, breast growth, skeletal changes, and
development of axillary and pubic hair. The presence of breasts and history of menstrual cycling were major clues
for suspecting pregnancy. Gamete development begins in fetuses of both genders with mitotic divisions in germ
cells. Meiosis begins in female fetuses but halts in meiosis I, resuming at puberty and halting in meiosis II, and
finishing meiosis only if fertilization occurs. Meiosis begins and is completed in males starting at puberty.