The filiform apparatus of a mature embryo sac is located at:

The correct answer is Option (1) → Micropylar end

A mature embryo sac is 7-celled and 8-nucleate. At the micropylar end lies the egg apparatus: two synergids and one egg cell. The synergids carry special cellular thickenings at their micropylar tip, called the filiform apparatus. It guides the pollen tube into the synergid.

(1) Micropylar end — Correct. The filiform apparatus is at the micropylar tip of the synergids.

(2) Chalazal end — Incorrect. The chalazal end holds the three antipodal cells. It is the end opposite to the egg apparatus.

(3) Antipodal cells — Incorrect. The antipodals are three cells at the chalazal end. They carry no filiform apparatus.

(4) Polar nuclei — Incorrect. The two polar nuclei lie in the large central cell, in the middle of the embryo sac.

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