Starting from a single Megaspore Mother Cell (MMC), how many meiotic and mitotic divisions are respectively required to form a typical mature embryo sac in angiosperms?

Step-by-step solution

The process of megasporogenesis involves a single Megaspore Mother Cell (MMC) undergoing one meiotic division to form a linear tetrad of four megaspores. In a typical angiosperm, three megaspores degenerate and one remains functional. During megagametogenesis, this single functional megaspore undergoes three sequential mitotic divisions to form 2, 4, and finally 8 nuclei, which then organize into a 7-celled mature embryo sac. Therefore, 1 meiotic and 3 mitotic divisions are required in total. Answer: 1 meiotic and