If the prey population in point B would drop due to bacterial infection, the predator population in point C would also decrease because their food supply is very low. In turn, if the predator population decreases, this gives time for the prey population to recover and increase in point D.

If almost the entire predator population at point F would drop, the prey population would increase in the next cycle. The prey becomes more abundant due to lack of predation.

If the entire population of prey at point D would diminish, the numbers of prey would increase due to the lack of predation in point E. Eventually, the extinction of predator species would cause a population explosion in the prey species and they might quickly degrade the habitat by eating more plants. To avoid this event from happening, some predator species can be reintroduced into the population to restore the balance in the ecosystem and to ensure the survival of the predators.