In angiosperms, one sperm will need to fertilize the actual egg, while the other will need to fertilize the endosperm.
Zooplankton ingest phytoplankton, along with any MeHg present in the phytoplankton but eliminate MeHg from their cells more slowly than they ingest it. This leads to bioaccumulation and magnification of MeHg concentrations in the zooplankton compared to the phytoplankton
Maintenance of a consistent body temperature