Introduction
  1. The chickaree lives in the forests of the Sierra Nevada and eats pine cones  .
  2. Animals depend on the plants of the forest for oxygen   as well as for food.
  3. Some plant seeds are dispersed by clinging to the coats   of animals, or in the digestive   tracts of animals.
  4. The pattern of interactions among organisms and their environment is called a(n) ecosystem  .
  5. The living or biotic part of an ecosystem is called a(n) community  .
  6. Through photosynthesis  , trees and other plants convert the energy of sunlight into the energy of chemical   bonds.
  7. The green plants are thus the producers   of the ecosystem.
  8. In contrast to the plant producers, the deer and mountain lion are consumers  .
  9. Organisms which break down and recycle materials in wastes and dead bodies are called decomposers  .
  10. Producers are often called autotrophs   - they make their own food; consumers and decomposers are called heterotrophs   - they get their food from other organisms.
Section I: Trophic Structure
  1. A butterfly is an example of a primary   consumer in the trophic pyramid.
  2. The hawk is a tertiary   consumer if it eats an insect-catching bird.
  3. Primary   consumers are also called herbivores.
  4. In a forest ecosystem, the insects outnumber the trees, so the pyramid of numbers   is partially inverted.
  5. The pyramid of biomass   may sometimes seem inverted if producers have a higher reproductive rate than consumers.
  6. The pyramid of energy flow   is always upright, since the number of calories always decreases   as one goes up each level.
Section II: Energy Flow
  1. Energy enters most ecosystems in the form of solar   radiation, and leaves as heat  .
  2. Because energy passes through the ecosystem and is not reused, the ecosystem is said to be a(n) open   system with regard to energy.
  3. A mouse is about 10   % efficient at turning cheese into cat food.
  4. Most food chains contain five   or fewer links.
  5. Plants convert about 1   % of solar energy into food for grasshoppers and mice.
  6. Energy export   occurs when energy leaves an ecosystem, while energy import   occurs when energy is introduced into an ecosystem.
  7. Our fossil   fuel reserves are composed of stored production energy from ecosystems of the past.
Section III: Materials
  1. In photosynthesis, carbon dioxide   and water   are combined to form glucose.
  2. The compounds from photosynthesis are broken down by respiration, where energy is release, and carbon dioxide   and water   are re-formed.
  3. With regard to materials, the ecosystem is a closed   system.
  4. Carbon moves from the atmospheric   pool to the biotic   pool in photosynthesis, and is transferred from the biotic pool back to the atmospheric   pool when CO2 is released as a product of respiration.
  5. The carbon trapped in ancient sediments makes up the sedimentary   pool, which cycles slowly under natural conditions.
  6. Tropic forests undergo rapid   recycling of materials, while fir forests undergo slow   recycling.
  7. Carbon dioxide in the atmosphere traps solar energy, keeping the earth warm - the so-called greenhouse   effect.
  8. Copper and cobalt are needed in only tiny amounts as cofactors   of certain enzymes.
  9. Only a few kinds of microorganisms can use N2 gas directly, through the process of biological nitrogen fixation  .
  10. In an ecosystem, energy movement is always one   -way, while materials are always reused  , recycled over and over.


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