Why do you think the zygote is dormant for sometime in a fertilised ovule?
At the time of fertilization, the zygote is formed by the fusion of the male gamete and the egg cell. The zygote thus formed remains dormant for a while to ensure the formation of the endosperm. The endosperm provides nutrition to the growing embryo. Once the endosperm is formed from the primary endosperm cell, the dormancy of the zygote ends and zygote development commences. Two sperm nuclei proceed into the female gametophyte. The zygote is formed by the fusion of the egg cell with one of the sperm nucleus. The other sperm nucleus fuses with the central cell to form a primary endosperm nucleus. This process is called triple fusion because it involves the fusion of three nuclei; one of the sperm nuclei and the other two of the central cell. The nucleus thus formed is called a triple fusion nucleus. This cell then goes on to develop into the endosperm.
