(a) Describe the process of double fertilisation in angiosperms.
(b) Trace the development of polyploidal cell that is formed after double fertilisation in a non-albuminous seed and albuminous seed.
a) Firstly when male gametes, fuses with the nucleus of the egg cell, to form a diploid zygote (syngamy) and secondly when the male gamete, fuses with two polar nuclei, to form (triploid) primary endosperm nucleus (triple fusion).
b) The primary endosperm nucleus undergoes successive nuclear divisions, to give rise to free nuclei, subsequent cell wall formation results in the cellular endosperm.