The embryo sac contains 3 antipodals, 3 synergids, 1 egg and 2 polar nuclei.
- After positive pollen–pistil interaction, the pollen tube develops and enters the ovule through synergids guided by filiform apparatus.
- One of the male gamete fertilises the female gamete to form diploid zygote.
- The another male gamete fuses with the secondary nucleus (polar nuclei if they are already fused) to form a triploid primary endosperm nucleus (PEN) that develops into endosperm.
- The three antipodals at chalazal end and synergids at micropylar end start degenerating.
