Currently, over three fourths of all living plants are angiosperms. The angiosperms developed a close contact with insects which promoted cross-pollination and resulted in more vigorous offspring. Their generation time to reproduce is short, and their seeds can be dispersed by animals. For these reasons, the angiosperms were able to travel and disperse all around the world. See also A Brief History of Life .
Polyploidy is an important mechanism in the evolution of plants.
It can be 3n, 4n or more. It arises as a result of meiotic irregularities and gives rise to sterile progeny which can still reproduce asexually. Polyploidy can be induced by treatment of colchicine. Triploid offspring can be produced by crossing a colchicine-induced or naturally occurring tetraploid and a diploid. Plant biology Plants are eukaryotic, multicellular organisms.