Distinguish between the pollen grains of
insect-pollinated and wind-pollinated flowers
Define self-pollination as the transfer of grains grains from the anther of a flower to the stigma of the same flower or different flower on the same plant
Define cross pollination as transfer of pollen grains from the anther of a flower ot the stigma of a species.
Describe the growth of the pollen tube and its entry into the ovule followed by fertilisation (details of production of endosperm and development are not required).