MITOCHONDRIA

Normal structures in cells. Mitochondria are located in the cell's cytoplasm outside the nucleus (which is home to the normal human complement of 46 chromosomes). Each mitochondrion has a chromosome made of DNA but, otherwise, the mitochondrial chromosome is quite different in size and shape from other chromosomes: The mitochondrial chromosome is much smaller, it is round (whereas the chromosomes in the nucleus are shaped like rods) and there are many copies of the mitochondrial chromosome per cell. No matter whether we are male or female, we all inherit our mitochondrial chromosome from our mother so we all owe our mitochondrial chromosomes to Eve (rather than to Adam).