Bayer and colleagues describe the first paternal effect on plant embryogenesis, and show that the timing of zygote elongation and the first division are mediated by a signal provided by the sperm ...

During fertilisation the haploid nucleus of a sperm cell and the haploid nucleus of an egg cell fuse together to form a diploid zygote.

There is an initial duplication of DNA before cell division followed by stages of ... each parent contributes 23 chromosomes to the zygote through a process of chromosomal reduction called meiosis ...