Practice question

Angiosperm gametophytes develop from haploid spores produced within sporangia located in third and fourth floral whorls according to classical ABC model. Third whorl stamens produce microsporangia generating male gametophytes pollen grains, while fourth whorl carpels form megasporangia ovules generating female gametophytes embryo sac. First whorl sepals and second whorl petals are sterile protective and attractive structures aiding pollination and preventing desiccation. This organization directly links MADS-box floral organ identity patterning to gametophyte generation location, elegantly coordinating transition from diploid sporophyte to haploid gametophyte phase during sexual reproduction of flowering plants.