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 were probably formed when one prokaryotic cell engulfed another and second cell became a friendly addition (endosymbiosis)-The first eukaryotic cells were probably heterotrophic-The heartwood of a tree is made of the _____ layers of the _____. oldest, xylem-The history of ecology is more like a bush than a tree.