Pollen Pollen Pollen is a fine to coarse powdery substance comprising pollen grains which are male microgametophytes of seed plants, which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require
Bee pollen in the chambers of honeybee hives, and sometimes in wood and mud created by female ground-nesting bees, such as the leafcutting bee. With the leafcutting bee, when the pollen ball is complete, a single female lays an egg on top of the pollen ball, and seals the brood cell. It differs from field gathered pollen as honey bee secretions induce a fermentation process, where biochemical transformations break down the walls of flower pollen grains and render the nutrients more readily available. Forager bees that gather pollen do not eat it themselves, since they stop producing the proteolytic enzymes necessary to