| In some cases, though, the unfertilised ovum itself is believed to be affected. |
| When a human sperm fertilizes a human ovum, a single cell is created with the potential to grow into a human person. |
| We rather think of the latter as a new form of life to whose nature both the ovum and the spermatozoon have made significant contributions. |
| As in most other animals, the sperm mitochondria penetrate the cell membrane of the ovum at fertilization. |
| On the 1st December I bred also from another ovum a small hymenopterous parasite. |
| The fertilised ovum was then implanted in the womb of the surrogate mother. |
