In angiosperms, the correct pairing is microspore—n.
Chromosome Counts in Angiosperm Life Cycle
The life cycle of angiosperms involves alternation of generations, with distinct haploid (n) and diploid (2n) stages. The microspore is a haploid cell produced by meiosis in the anther and gives rise to the male gametophyte (pollen grain) through mitotic divisions. Therefore, it correctly has a chromosome count of n.
Similarly, the megaspore is also a product of meiosis in the ovule and is haploid (n), not diploid (2n). Thus, any pairing of megaspore with 2n is incorrect. The egg cell, derived from the megaspore via mitosis, remains haploid (n), making pairings such as egg—2n incorrect.
Endosperm and Pollen Grain Chromosome Counts
The endosperm in angiosperms is typically triploid (3n), formed by the fusion of a sperm cell (n) with two polar nuclei (each n, together 2n) in the embryo sac. Hence, endosperm—2n is incorrect. The mature pollen grain contains two cells—the tube cell and the generative cell—both of which are haploid (n), so pollen grain—2n is also incorrect.
Thus, among common options, only microspore—n is correctly paired.
