Why do most communities have only about 3 or 4 tropic levels?

Which is an example of a population?

Which of the following types of stars is most likely to end up as a supernova? in graph a, the curve peaks at 800 nm, in the red section of the visible light spectrum. in graph b, the curve peaks at 550 nm, in the green section of the visible light spectrum. in graph c, the curve peaks at 450 nm, in the blue section of the visible light spectrum. in graph d, the curve peaks at 300 nm, in the violet section of the visible light spectrum. a b c d

Energy for use in cells is stored in form of 1.chemical bond energy 2.physical energy 3.heat energy 4.mechanical energy.