Chromosones

• Chromosones carry genetic information in a molecule called DNA
• DNA exists in a cell's nucleus within structures called chromosomes.
• Each section of a chromosome that contains the code for the production of a particular protein is called a gene.
• Each human body cell contains 46 chromosomes. These can be arranged into 23 pairs.
• Each chromosome in a pair carries the same types of genes. The 23rd pair are the sex chromosomes:

  • In females, the two chromosomes are identical in shape. There are two X chromosomes. Females are referred to as XX.
  • In males, one of the chromosomes is a different in shape. There is an X and also a Y chromosome. Males are referred to as XY.