Flowers are reproductive structures of plants. Flowers can be complete or incomplete. Complete flowers consist of vegetative and reproductive parts
Plants can reproduce sexually or asexually. Sexual reproduction requires sperm and eggs, producing genetically different offspring. Asexual reproduction produces genetically identical offspring without sex cells
Pollen is a powdery substance produced by seed plants for sexual reproduction. Pollen grains contain male gametes and are protected by sporopollenin coating. Pollen grains vary in size from 2.5-5 μm to 90-100 μm in diameter