BI102

General Biology

Spring 2012

Dr. Brian K. Penney

Goulet 2320

603 641-7149

bpenney@anselm.edu

Brian K. Penney 's web page

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1. Define an ecosystem, and compare the flow of energy versus chemicals through an ecosystem.

   Ecosystems include the biological community and abiotic resources. Two fundamental processes in ecosystems are

   • energy flow: energy comes from an outside source, flows one way through various components of an ecosystem and is then lost

   • chemical cycling: materials pass through biotic and abiotic reservoirs, often changing form and availability to other reservoirs

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2. Define and compare the concepts of a food web versus food chain.

   Trophic structure determines energy flow, and is a key factor in ecosystem dynamics.

   • the food chain is an abstract grouping of organisms in an ecosystem based on tropic level (producers, primary and secondary consumers, detritivores). In reality, food chains interconnect to form food webs, and the variety of links stabilize ecosystems

   • primary production and rates of transfer differ among ecosystems and limit the length and complexity of food webs

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3. Compare the primary production of tropical rain forests, coral reefs and open ocean. Explain why the differences between them exist.

   • See 37.15

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4. Explain how water, carbon, nitrogen and phosphorous cycle within ecosystems, and how humans have affected each cycle.

   for each cycle, you should know the important reservoirs, links between them and which links are one-way versus-two way. These four cycles are among the most important because they concern the major materials required by plants for photosynthesis.

   • WATER

   • CARBON

   • NITROGEN

   • PHOSPHOROUS

Copyright 2007-2012, Brian K. Penney

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