(a) The sequence begins with the MMC undergoing meiosis within the micropylar region of the nucellus, producing four megaspores (A). Of these, only one megaspore remains functional after the other three degenerate (B). This functional megaspore then undergoes several rounds of mitotic divisions without cell wall formation, leading initially to a 2 -nucleate stage (C). This is followed by further divisions to reach the 4-nucleate and eventually the 8 -nucleate stages (D). Finally, the cell wall formation occurs, establishing the structure of the female gametophyte with six of the eight nuclei encapsulated in cell walls, and the two polar nuclei situated in the large central cell (E).