Double Fertilization in Flowering Plants — NEET Biology
✅ Asked in NEET 2023After entering one of the synergids, the pollen tube releases the two male gametes into the cytoplasm of the synergid. One of the male gametes moves towards the egg cell and fuses with its nucleus thus completing the syngamy. This results in the formation of a diploid cell, the zygote. The other male gamete moves towards the two polar nuclei located in the central cell and fuses with them to produce a triploid primary endosperm nucleus (PEN). As this involves the fusion of three haploid nuclei it is termed triple fusion. Since two types of fusions, syngamy and triple fusion take place in an embryo sac the phenomenon is termed double fertilisation, an event unique to flowering plants. The central cell after triple fusion becomes the primary endosperm cell (PEC) and develops into the endosperm while the zygote develops into an embryo.
Double fertilization is the fusion of TWO separate sperm nuclei with different targets in the embryo sac. The first sperm fuses with the egg nucleus (syngamy) to form a diploid zygote; the second fuses with two polar nuclei (triple fusion) to form a triploid primary endosperm nucleus. Students often confuse which sperm does what or think both sperm fuse with the egg. Remember: one sperm → egg (zygote), one sperm → polar nuclei (endosperm). This unique process occurs ONLY in flowering plants and is tested because it's a defining characteristic of angiosperms that directly explains embryo and nutrient tissue formation.
This paragraph was tested 2 times in NEET.
In angiosperm, the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are:
Double fertilisation is exhibited by (NEET 2017)
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.