В каждом из 4 гнёзд пыльника из клеток археспория после мейоза образуются микроспоры, которые затем прорастают в мужские гаметофиты — пыльцевые зёрна.

Translate this to English?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
The pollen is set free by the opening (dehiscence) of the anther, generally by means of longitudinal slits, but sometimes by pores, as in the heath family ( Ericaceae ), or by valves, as in the barberry family ( Berberidaceae ).