Stage 5 of fertilization:
Formation of male and female pronuclei:
- Chromosomal material of the sperm decondensates and enlarges
- Chromosomal material of the ovum decondensates following the completion of meiosis
At this stage, the male and female pronuclei are indistinguishable.
As they grow, the pronuclei replicate their DNA _ still 1N (haploid)- 23 chromosomes, each in chromatid pairs