The functional megaspore develops into:

The correct answer is Option (2) → Embryo sac

Each megaspore mother cell of the ovule divides by meiosis to form four megaspores. In most flowering plants, one megaspore stays functional and the other three degenerate. The functional megaspore grows into the female gametophyte, the embryo sac. This is called monosporic development.

(1) Funicle — Incorrect. It is the stalk by which the ovule is attached to the placenta.

(2) Embryo sac — Correct. Its nucleus divides three times to give the 8-nucleate, 7-celled embryo sac.

(3) Endosperm — Incorrect. It is a nutritive tissue. It develops from the primary endosperm cell after triple fusion, which happens after the embryo sac has formed.

(4) Nucellus — Incorrect. It is the mass of cells, rich in food, that lies inside the integuments. The embryo sac is located in it.

NCERT Extract:
The Pistil, Megasporangium (ovule) and Embryo Sac – …