• Question: If you have 23 pairs of chromosomes (46 in total), how can you have one chromosome in each cell?

    Asked by kattypuss to Rachael, Penny, Jennifer, Jean-Paul, David, Dave, Andrew on 6 Jan 2014.
    • Photo: Penelope Mason

      Penelope Mason answered on 6 Jan 2014:

      You have 23 pairs in each normal cell, so you have two copies of each chromosome. Normal cells are therefore called diploid. Egg and sperm cells have only one copy of each chromosome (unless they have mutations) so that when they fuse together the resulting cell has two copies like other normal cells. So these are a special case, and are called haploid. This is how you come to have half your chromosomes from one parent and half from the other.

    • Photo: David Christensen

      David Christensen answered on 6 Jan 2014:

      Penelope’s right. We have 46 chromosomes in every cell of our bodies (except sperm and egg cells). The 23 pairs of chromosomes have all of the information to make you as you are, so all cells need all of this information to do their jobs. Each cell is then given a bit more information, such as about where it is in the body and can communicate with other cells around it so that it knows exactly what its job is and which parts of all of the chromosomes it needs to use.

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