X and Y Chromosomes.
Your Chromosomes Control Whether You Are Male or Female.
There are 23 matched pairs of chromosomes in every human body cell. The 23rd pair are labelled ** or XY. They're the two chromosomes that decide whether you turn our male or female.
ALL MEN HAVE X AND A Y CHROMOSOME: XY
THE Y CHROMOSOME CAUSES THE MALE CHARACTERISTICS.
ALL WOMEN HAVE TWO X CHROMOSOMES: **
THE ** COMBINATION ALLOWS FEMALE CHARACTERISTICS TO DEVELOP.
When making sperm, the X and Y chromosomes are drawn apart in the first division in meiosis. There's a 50% chance that each sperm cell gets an X chromosome and a 50% chance it gets a Y chromosome. A similar thing happens when making egg cells. But the original cell has two X chromosome, so each cell has one X chromosome.
Genetic Diagrams Show…