In the majority of angiosperms:

Step-by-step solution

MEGASPOROGENESIS: Definition: The process of formation of megaspores from megaspore mother cell (MMC) is called megasporogenesis. i) Embryosac generally develop from a single megaspore that differentiate from a single megaspore mother cell (MMC) in the micropylar region of the nucellus. ii) MMC is a large cell containing dense cytoplasm and a prominent nucleus. iii) The MMC undergoes meiosis and forms a linear tetrad of four haploid megaspores. Out of which one remains functional (chalazal end) and three degenerate