Distinguish between the bottom-up and top-down models of community organization.

Bottom -up models of community:

The bottom up models of the community represents the unidirectional influence of the community. The model shows from the lower to the higher tropic levels in the community. This model determines the nutrient minerals and the primary producer abundance.

Top - down models of community :

The top down model of the community represents the one tropic level to the other tropic levels. This model is also known as cascade model. This model determines how the one tropic level controls the other tropic level. For example: the control of herbivores by the predators.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.