The functional megaspore in an angiosperm develops into
During megasporogenesis, the megaspore mother cell(2n) undergoes meiosis to form 4 haploid megaspores. Out of the four haploid megaspores, one remains functional and the other three degenerate. This functional megaspore undergoes free nuclear divisions and forms the 7 celled, 8 nucleated embryo sac.