What type of pathogen is responsible for epidemics and pandemics

Typically viruses, for example avian influenza (bird flu).

All birds are thought to be susceptible to infection with avian influenza viruses; certain avian influenza viruses (H5 and H7) may cause lethal outbreaks in poultry. Humans can occasionally be infected with avian influenza A viruses (10).

To receive pollen grains

Explanation:

A flower is a modified shoot which is meant for reproduction. The stamen is the male reproductive organ and the pistil is a flower's female organ. A pistil is located in the centre of the flower and is surrounded by petals, sepals and stamens.

Some flowers have a long pistil that reaches above the petals to receive wind disseminated pollen grains. This helps transfer pollen and fertilize the ova in the ovaries.