The role of chromosomes in sex & gender
- Chromosomes are made of nucleic acids (mainly DNA in humans) and protein and are found in the nucleus of cells
- Humans have 23 pairs of chromosomes in each cell (the 23rd pair determines the baby’s sex) with the chromosome pattern for a male being XY (one of the pair looks like and X and one like a Y) and for a female it is XX
- Chromosomes determine a baby’s sex at fertilisation: all eggs carry an X chromosome, and if the egg is fertlised by a Y-chromosome carrying sperm, the the child will be a male and if the sperm carries an X chromosome, then the baby will be female
- During prenatal development, individuals have gonads which are identical and have the ability to turn into either testes or ovaries, so if a Y chromosome is present it produces a protein which causes the gonads to become testes
The 23rd chromosome pair of a male