Use in clinical context
It is important that gametes have half the amount of DNA (haploid) so that at fertilisation when the egg and sperm combine it results in a cell with a full complement of DNA. Errors can occur during meiosis producing gametes with an extra or missing chromosome. The consequences of this following fertilisation depend on which chromosomes are affected. Often the embryo is not viable, but some of these errors can lead to trisomy conditions or sex chromosome disorders.