Humans typically have 46 chromosomes in most body cells, arranged as 23 pairs.

Basic breakdown

  • 23 pairs = 46 individual chromosomes.
  • 22 of those pairs are called autosomes and are the same in males and females.
  • The last pair are the sex chromosomes :
    • Most females: XX
    • Most males: XY

Special case: reproductive cells

  • Egg and sperm cells each have 23 single chromosomes (not pairs).
  • When they join at fertilization, they form a cell with 46 chromosomes again.

When the number is different

  • Having extra or missing chromosomes is called aneuploidy.
  • Example: Down syndrome often involves an extra copy of chromosome 21, giving 47 chromosomes per cell.

Information gathered from public forums or data available on the internet and portrayed here.