Stage 6 of fertilization:
Membranes of the pronuclei break down, chromosomes condense and arrange themselves for mitotic cell division
- On membrane dissolution, there is 1 cell with 46 chromosomes = diploid (2N)
- The first cleavage follows shortly, leaving 2 cells, each with 46 chromosomes.
- Mitosis in the new zygote uses centrioles derived from the sperm. The oocyte has no centrioles.