What percentage of terrestrial plants are colonized by arbuscular mycorrhizae?

What percentage of terrestrial plants are colonized by arbuscular mycorrhizae?
 
  A) 10
  B) 25
  C) 50
  D) 85

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Two main symbionts of termites are ________ and ________.
 
  A) archaea / bacteria
  B) bacteria / fungi
  C) bacteria / protists
  D) fungi / protists

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Ruminants digest bacterial cells as a primary source of
 
  A) carbohydrates.
  B) vitamins and proteins.
  C) proteins.
  D) vitamins.

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Which of the following do dinoflagellates most commonly associate with in a mutualistic relationship?
 
  A) clams
  B) corals
  C) flatworms
  D) snails

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How do phototrophic microorganisms benefit when associating with corals?
 
  A) Calcium and carbonate ions are released, which help buffer the pH and prevent dramatic pH shifts.
  B) The coral skeleton is used as a source of bicarbonate for the autotrophic growth of the phototrophs.
  C) The coral skeleton is an extremely efficient light-gathering structure that greatly enhances light harvesting for photosynthesis.
  D) The water's temperature in and around the coral skeleton is much warmer.