Ecosystems CD

    Section I Energy: Trophic Structure
  1. There are about     billion bacteria in every pound of forest litter.
  2. A butterfly is an example of a          consumer in the trophic pyramid.
  3. The hawk is a           consumer if it eats an insect-catching bird.
  4.          consumers are also called herbivores.
  5. There are       million individual plant producers and       tertiary consumers per acre of grassland.
  6. The pyramid of          may sometimes seem inverted if producers have a higher reproductive rate than consumers.
  7. The pyramid of              is always upright, since the number of calories always            as one goes up each level.
    Section II Energy Flow
  1. Energy enters most ecosystems in the form of        radiation, and leaves as       .
  2. A lark is a            consumer, and is about     % efficient in turning grasshoppers into hawk food.
  3. Most food chains contain    or fewer links.
  4. Plants convert about    % of solar energy into food for grasshoppers and mice.
  5. Energy         occurs when energy leaves an ecosystem, while energy         occurs when energy is introduced into an ecosystem. Thus ecosystems are almost never fully         .
    Section III Materials
  1. The Carbon cycle involves 3 pools: the              ,         , and              pools.
  2. Carbon moves from the              pool to the         pool in photosynthesis, and is transferred from the         pool back to the              pool when CO2 is released as a product of respiration.
  3. Tropic forests undergo        recycling of materials, while fir forests undergo       recycling.
  4. In an ecosystem, energy movement is always          , while materials are always           .
  5. A             ion is part of one of the enzymes which fix nitrogen.
Questions
  1. What level consumers should cars be classified?         
  2. Which carbon pool do cars consume?             
  3. Sketch an oxygen cycle involving photosynthesis and respiration.