. P OST - FERTILISATION : S TRUCTURES AND E VENTS Following double fertilisation, events of endosperm and embryo development, maturation of ovule(s) into seed(s) and ovary into fruit, are collectively termed post-fertilisation events. . .
Endosperm Endosperm development precedes embryo development. Why? The primary endosperm cell divides repeatedly and forms a triploid Figure . (a) Fertilised embryo sac showing zygote and Primary Endosperm Nucleus (PEN); (b) Stages in embryo development in a dicot [shown in reduced size as compared to (a)]