For most terrestrial ecosystems, pyramids of numbers, biomass, and energy are essentially the same-they have a broad base and a narrow top. The primary reason for this pattern is that Question 44 options: a. secondary consumers and top carnivores require less energy than producers. b. at each step, energy is lost from the system as a result of keeping the organisms alive. c. as matter passes through ecosystems, some of it is lost to the environment. d. biomagnification of toxic materials limits the secondary consumers and top carnivores. e. top carnivores and secondary consumers have a more general diet than primary producers.

Generally Ecological pyramids helps to visualise the structure of Ecosystem.Its diagrammatically showed the relative amounts of numbers of organisms ,their energy, and the amount of energy that is converted in living tissue as usable mass (biomass) at different tropic levels.

Basically, large amount of energy is lost as energy flow from one tropic level to another in an ecosystem. This can be explained with the second law of thermodynamics; which states that in the conversion of energy from one form to another in a system, there is always a tendency towards disorderliness.That is the entropy changes of the universe can never be negative.Relatively in a biological system, this means that energy is lost in metabolic process( glycolysis, chemeosmosis, assimilation, growth .......) as heat, as organisms at one tropic level is consumed by another at the next level, from the base to the peak of these pyramids.

The amount of energy transfer efficiency among the two successive tropic levels is obtained by dividing the energy transfer at present tropic level with the energy transfer at previous tropic levels and mutiply the results by 100% . This known as Tropic level transfer efficiency(TLTE) .

The lower energy efficiency between successful present and previous tropic levels in these pyramids accounts for the similarities.