Question

Name the nuclei that participate in the triple fusion.

Answer 1

Hint: Double fertilization is the process in which the two male gametes fuse with 2 cells of the female gametophyte.
In this process, syngamy and triple fusion are seen which forms zygote and PEN or the primary endosperm nucleus respectively.

Complete answer: The 7 Celled 8 nucleated female gametophyte in angiosperms show double fertilization.
1. Double Fertilization is the process in which the fusion of polar nuclei with one male gamete and that of the egg cell with another male gamete.
2. The fusion of egg and male gamete is known as Syngamy and that of the male gamete with the polar nuclei is known as triple fusion.
3. While syngamy forms the zygote, triple fusion is said to give rise to a PEN or the primary endosperm nucleus which further forms the endosperm.
This phenomenon of double fertilization is seen in angiosperm plants.
4. The endosperm hence produced is triploid and is known to provide nourishment to the developing zygote.

So the correct answer is ‘A sperm nucleus and two polar nuclei’

Note: The primary nuclei fuse with the male gamete to form the primary endosperm nuclei, which is triploid, and later forms the endosperm because the primary endosperm nucleus or the PEN is triploid, this process is termed as triple fusion.