Post-fertilisation Events

Post-fertilisation Events

Everything that happens after the male and female gametes fuse to form the zygote is grouped together as the post-fertilisation events of sexual reproduction. Where fertilisation itself is essentially a single decisive moment — the fusion of two gametes — the post-fertilisation stage covers the whole subsequent process by which that single fertilised cell becomes a new, fully formed organism.

Two closely linked processes make up this stage:

• Formation of the zygote — the diploid cell created immediately by fertilisation, whose further fate depends on the kind of organism and the environment it develops in.
• Embryogenesis — the process by which that zygote divides and its cells differentiate to build the embryo, ultimately giving rise to a complete new individual. …