1. Double fertilisation is an event unique to angiosperms and gymnosperms. 2. The zygote develops into an embryo 3. Primary endosperm nucleus (PEN) develops into endosperm which provides nourishment to the developing embryo. 4. The synergids and antipodals degenerate after fertilisation. 5. During these events the ovules develop into seeds and the ovaries develop into fruit. Regarding 1,2,3,4 and 5: