I believe that last one is true (photosynthesis of plants)
good luck
The number of predators and preys change from time to time following
cycles. Whenever there is fewer prey, predators start dying because they
have not enough to eat; however, that provokes the population of prey
to be increased while there are fewer predators. So if suddenly the
number of prey gets bigger, regardless of the number of predators, the
cycles get disturbed by this sudden occurrence. The predators will get
more to hunt, therefore getting more violent.
I think it's Genetic engineering
