This seems easy.. You got this.
The Mitochondria breaks down sugar to supply and power the cell
Remember that the mitochondria is the powerhouse of the cell, without it, the cell wouldn't be able to function
99% of calcium is found inside the cells of the body.
The answer would be D. Tropical Rainforest, this would be due to the abundance of rain which creates plenty of vegetation and then, more herbivores will live in the rainforest, and the more herbivores there are, the more carnivores will come to the rainforest. The canopy of the tall trees also provide shelter for countless of thousands of species of birds.
When the structure and function of an organism adjusts to its environment it is adapting.