Biomass consists of ________. (Multiple Choice)

Biomass consists of ________.
 
  A) dead tissues and wastes
  B) living organisms and cells
  C) polymerized, non-identifiable molecules
  D) identifiable biomolecules
  E) all of the above

Question 2

Humic substances consist of ________.
 
  A) dead plant & animal tissues
  B) living organisms and cells
  C) polymerized, non-identifiable molecules
  D) identifiable biomolecules
  E) all of the above

Question 3

After drying to eliminate the water in plant litter, which two elements account for about 80 of the dry weight?
 
  A) Ca and C B) N and S C) C and H D) N and C E) C and O

Question 4

Green plant residues such as grass clippings or a green manure crop generally have a water content of about ________  by weight.
 
  A) 75 B) 45 C) 25 D) 10 E) 95

Question 5

Which of the following is a greenhouse gas contributed to the atmosphere by soils?
 
  A) carbon dioxide
  B) nitrous oxides
  C) methane
  D) all of the above
  E) none of the above

Question 6

Which of the following is (are) major sources of the carbon dioxide now being added to the atmosphere in excess of the amount taken out by plants?
 
  A) loss of soil organic matter
  B) destruction of natural forests
  C) burning of fossil fuels
  D) all of the above
  E) none of the above

Question 7

Suppose leaves containing 1000 kg of carbon fell to the forest floor in a humid temperate environment. After a year or so, how many kg of that carbon would you expect to remain in the soil as microbial biomass and humus?
 
  A) 20 B) 10 C) 200 D) 400 E) 800