The solutes move down<span> their concentration gradient and do not require the expenditure of cellular energy.</span>
Mutualism is the answer simply because the bee and the flower depend on each other for survival. their mutual dependence is necessary for their well-being. obviously without the bee there wouldn't be a flower because bees carry pollen around and without flowers there wouldn't be bees because bees feed on nectar from flowers.
It helps maintain homeostasis by transforming energy that can be used to do cellular work.