Royal jelly, a thick, milky substance secreted by young nurse honeybees to feed a bee colonyâs larvae, most notably the queen larvae, is a rich source of nutrients, as well as acetycholine, a neurotransmitter that plays a critical role in cognitive function.
The origin of the eukaryotic cell is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The timing of this series of events is hard to determine; Knoll (2006) suggests they developed approximately 1.6â2.1 billion years ago.
The First Eukaryotic Cells. Fossils of the first eukaryotic. cells do not appear in rocks until 1.5 billion years ago, over 2. billion years after bacteria. Multicellular life is restricted to. the four eukaryotic kingdoms of life.