Multicellularity first developed about 1.2 billion years ago, probably through joining or division of cells that eventually led to the of multicellular organisms.

As a bee feeds upon the nectar produced by a flower, the bee may become coated with the flower's pollen. as the bee flies from flower to flower, some of this pollen may contact a flower's pistil, resulting in pollination. this relationship between the bee and the flower is an example of a. parasitism b. commensalism c. mutualism d. competition