Explain the difference between the between top-down and bottom-up models. Complete the following sentences and place them in a logical order a. laws of thermodinamics b. primary producers c. the lowest d. top-down e. positive f. carnivores g. bottom-up h. herbivores i. highest According to the ____ model, control of population densities starts at ____ trophic levels. Support for this model comes from the ____ , which state that energy is lost with successive transfers through trophic levels, starting from ____ and moving to____ , then to ____ Additional support comes from the fact that providing fertilizer to plants frequently has a pronounced ____ effect on the population sizes, survivorship, fecundity, and growth of herbivores. However, some populations appear to be controlled by the presence and level of predation. Since predators occupy the ____ trophic levels, predator-controlled populations are considered to be regulated from the ____.