How do chromosomes determine biological sex?
Quick Answer
In typical human development, the presence of a Y chromosome and the SRY gene usually triggers male-typical gonadal development. Without a Y chromosome, development usually follows the female pathway.
The Full Story
Humans usually have 46 chromosomes arranged in 23 pairs, including one pair of sex chromosomes. Typically, XX leads to ovarian development and XY leads to testes development because the SRY gene on the Y chromosome initiates a cascade of gene activity. However, sex development is more complex than chromosomes alone, and variations such as Turner syndrome, Klinefelter syndrome, and differences in sex development can alter the usual pattern. Biological sex is determined by genetics, hormones, and development together.
Key Facts
YouTube Angle
Suggested video title for this topic:
"How chromosomes help set the body’s developmental path"
Was this answer helpful?
Tap a reaction — it helps us pick what to cover next.