The mitochondria makes energy for the cells.
They ensured that balance in the ecosystem was maintained. They ensure that the genetic diversity and species is maintained. Sea otters applied natural selection pressures on the sea urchins population hence maintaining their level such that they will not overgraze on the kelps. Overgrazing would severely affect the sea urchin population and consequently severely affect the sea otters population too.
Im sorry i don’t understand
The answer is to move molecules across the membrane against a gradient.
