There are a lot of adaptations, and they are different depending on how the plant is pollinated. For example in wind pollinate species, the anthers hang out of the flower so they can get dispersed by...
They are produced in the anther and are male sex cells for a plant. They contribute by being the reproductive cells together with the female sex cells and get fertilised to eventually develop into a...
this is because premature pollen grain do not contain the sperm cell for fertilization. only the generative nucleus in mature pollen grain will divide mitosisly to form sperm cell for fertilization