In a typical angiosperm embryo sac, the special cellular thickenings known as the filiform apparatus are precisely located at the:

Step-by-step solution

According to NCERT, in the female gametophyte (embryo sac) of an angiosperm, the synergids possess special cellular thickenings specifically at their micropylar tip. These thickenings are collectively called the filiform apparatus. The filiform apparatus plays an important role in guiding the pollen tube into the synergid. It is not found at the chalazal tip, nor is it a part of the egg cell or the antipodals. Answer: Micropylar tip of the synergids