Which among these has helped the angiosperms to become the most dominant form of plant?
Both a and b
Vascular tissue - the xylem and phloem, and flowers in angiosperms have helped them to grow in various conditions. While the vascular system is most well defined in angiosperms, the flowers are their exclusive feature, the reproductive units of angiosperms. With the advent of flowers, the pollination process became more elaborate, meaning it was not only dependent on wind but insects and animals could also assist in pollination thereby increasing the spread of these plants. Further, pollination results in the formation not only of the seed, as in the gymnosperms, but also the fruit through double fertilization. With fruit, seed development is even more ensured and its natural dispersal is improved.