Question: 119 In angiosperm, the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are :
(1) Synergids, Zygote and Primary endosperm nucleus
(2) Synergids, antipodals and Polar nuclei
(3) Synergids, Primary endosperm nucleus and zygote
(4) Antipodals, synergids, and primary endosperm nucleus
Answer: Option (1)
Explanation:
In the embryo sac of angiosperms, different cells have different ploidy levels.
Synergids are haploid structures as they are part of the female gametophyte and contain a single set of chromosomes.
After fertilization, one male gamete fuses with the egg cell to form the zygote, which is diploid due to the fusion of two haploid nuclei.
The second male gamete fuses with the two polar nuclei during double fertilization to form the primary endosperm nucleus, which is triploid.
Thus, the correct sequential order of haploid, diploid and triploid structures in a fertilized embryo sac is synergids, zygote and primary endosperm nucleus.
Hence, Option (1) is the correct answer.