Q.14 In a fertilised embryo sac, the haploid, diploid, and triploid structure are

(1) synergid, zygote and primary endosperm nucleus

(2) synergid, antipodal and polar nuclei

(3) antipodal, synergid and primary endosperm nucleus

(4) synergid, polar nuclei and zygote

 
(a)

 (i) Synergid—haploid

(ii) Polar nuclei—haploid

(iii) Antipodal—haploid

(iv) Zygote—diploid

Since, all these cells three cells (synergid, polar nuclei and antipodals are) formed by mitosis from the functional megaspore, they are haploid (n).
Egg cell fertilises with the male gamete to form a diploid zygote.

(v) Primary Endosperm Nucleus (PEN).
Diploid secondary nucleus fertilises with a haplold male gamete to form a triploid
PEN.