Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Chromosome 9 inversion ?
    ### Response:
    Chromosomes are the structures found in every cell of the body that contain our DNA, the instructions that tell our body what to do. Humans have 23 pairs of chromosomes, which means that each human cell contains 46 chromosomes. Each chromosome has a p and q arm; p is the short arm and q is the long arm.
    