Question

After double fertilisation, __________ degenerate, ________ forms into an embryo, _________ forms endosperm.

• A. synergids, zygote, secondary nucleus
• B. antipodals, zygote, PEN
• C. antipodals, endosperm, embryo
• D. antipodals, PEN, zygote

Answer 1

The correct option is B antipodals, zygote, PEN

Double fertilisation is unique to flowering plants. It involves syngamy and triple fusion. After double fertilisation, antipodals and synergids degenerate and the zygote divides and develops into an embryo.

The endosperm is triploid as it is formed by the fusion of three haploid nuclei. Fusion of one male gamete (n) with the diploid secondary nucleus (2n) (formed by fusion of two haploid polar nuclei) results in the formation of triploid (3n) primary endosperm nucleus (PEN). PEN divides and develops into a triploid nutritive tissue, the endosperm.