Functional megaspore in an angiosperm develops into:

Megaspore is the first cell of the female gametophytic generation in angiosperm. It is formed from the megaspore mother cell by meiosis. Out of the four cells created, only one megaspore develops, and remaining three degenerates. The formation of the female gametophyte from a single functional megaspore is called as monosporic development. It undergoes three successive generations of free nuclear mitosis to form 8-nucleated and 7-celled embryo sac.