Well the insects eat the plant and the small animals eat the insects and so on.if the insects die the food chain is broken.
D. Predators
Predators keep populations of other species in check. This was pretty clearly demonstrated in Yellowstone National Park after the wolves were eradicated there. The deer populations increased to the point that the aspen trees nearly disappeared due to the saplings' being eaten by deer. Since the reintroduction of wolves to the park, the aspen trees have begun to flourish once again.
The answer to this question is Homeostasis <span />
The answer to your question is both C
Cellular respiration occurs with a product of Carbon Dioxide (CO2)
