Yes
of course!
No, an ecosystem as well as supporting the food chain also supports the organisms with an environment in which to live and bread.
because the humans has more energy
because it needs a lot of energy to get the food chain to cycle.
A food web can more readily react to changes in the environment that impact one or more species. Also a food web is sometimes strengthened by the loss of one or more species if that species is overly aggressive, whereas a food chain is only as strong as it's weakest link and is always diminished or destroyed by the loss of any member. In short, a food web is more adaptive than a food chain and usually more diverse with more opportunity for cooperative advantage, improving chances of survival over a chain for the included species, especially species higher in the web (further from photosynthesis).
Because the food web contains2 and more food chains
An organism that is omnivorous, like a human, can belong to more than one food chain as it can consume both plants and animals for energy. By feeding on a variety of organisms, omnivores can occupy multiple trophic levels in different food chains.
the food
the food
the food
A food web can more readily react to changes in the environment that impact one or more species. Also a food web is sometimes strengthened by the loss of one or more species if that species is overly aggressive, whereas a food chain is only as strong as it's weakest link and is always diminished or destroyed by the loss of any member. In short, a food web is more adaptive than a food chain and usually more diverse with more opportunity for cooperative advantage, improving chances of survival over a chain for the included species, especially species higher in the web (further from photosynthesis).
Typically, the food chain is like a pyramid more than a chain. The lower on the food chain an organism is, the more of them that there are, because the lower organisms are usually smaller so it takes more of them to feed the larger ones at the top. ie sardines eat plankton, tuna eat sardines, and sharks eat the tuna.....each one is bigger than the other so there are more plankton than tuna, and more tuna than sharks.