BSC 2023 Ch 55

BSC 2023 Ch 55 The biggest difference between the flow of energy and the flow of chemical nutrients in an ecosystem is that __________. - Answer- nutrients are recycled, but energy is not The biggest difference between the flow of energy and the flow of chemical nutrients in an ecosystem is that nutrients are recycled, but energy is not. Chemical nutrients can be recycled within ecosystems through biogeochemical cycles. Energy is lost from an ecosystem as a result of respiration. It is incorrect to say that the biggest difference between the flow of energy and the flow of chemical nutrients in an ecosystem is that the amount of energy is much greater than the amount of nutrients. Energy and nutrients are not directly comparable in this fashion. It is incorrect to say that the biggest difference between the flow of energy and the flow of chemical nutrients in an ecosystem is that energy is recycled, but nutrients are not. It is incorrect to say that the biggest difference between the flow of energy and the flow of chemical nutrients in an ecosystem is that organisms always need nutrients but they don't always need energy, or that organisms always need energy but they don't always need nutrients. Organisms always need both. - AnswerPrimary producers are _________. - Answer- autotrophs Primary producers are autotrophs. Ecologists group species into trophic levels based on species' main sources of nutrition and energy. The trophic level that ultimately supports all the other levels consists of autotrophs, also called the primary producers of the ecosystem. Most autotrophs are photosynthetic organisms that use light energy to synthesize sugars and other organic compounds, which they use as fuel for cellular respiration and as building materials for growth. The most common autotrophs are plants, algae, and photosynthetic prokaryotes, although chemosynthetic prokaryotes are the primary producers in ecosystems such as deep-sea hydrothermal vents and places deep below the ground or ice. Organisms in trophic levels above the primary producers are heterotrophs, which depend directly or indirectly on the outputs of primary producers for their sources of energy. Herbivores, which eat plants and other primary producers, are primary consumers. Carnivores that eat herbivores are secondary consumers, and carnivores that eat other carnivores are tertiary consumers. "Heterotrophs" is incorrect because heterotrophs are organisms that obtain organic food molecules by eating other organisms or substances derived from them. "Grain farmers" is incorrect because these farmers plant grains, which are organisms that are autotrophs. "Grazers" is incorrect because grazers are herbivores or consumers that eat the primar