Quiz on Degradation of Organic Matter

What is the primary role of heterotrophic microbes in the carbon cycle?

• Synthesis of organic material

• Absorption of atmospheric nitrogen

• Degradation of organic material

• Production of fossil fuels

Which of the following is the largest reservoir of organic carbon?

• Atmospheric CO2

• Dissolved organic carbon (DOC)

• Soil organic material (SOM)

• Dissolved inorganic carbon (DIC)

What process involves the breakdown of organic material to its inorganic constituents?

• Decomposition

• Mineralization

• Photosynthesis

• Fermentation

Which organisms are primarily responsible for the majority of respiration in aquatic environments?

• Fungi

• Insects

• Plants

• Bacteria

What term describes the food web that consists of organisms feeding on dead organic matter?

• Microbial loop

• Detrital food web

• Herbivorous food web

• Carnivorous food web

Which of the following compounds is most difficult for microbes to degrade?

• Starch

• Cellulose

• Lignin

• Proteins

What is the primary function of ectoenzymes in microbial degradation?

• Transporting nutrients

• Hydrolyzing high molecular weight compounds

• Storing energy

• Regulating pH levels

Which process is described as the release of fresh organic compounds stimulating the degradation of older organic material?

• Priming effect

• Mineralization

• Fermentation

• Hydrolysis

What is the main component of wood that is difficult to degrade?

• Cellulose

• Hemicellulose

• Starch

• Lignin

Which group of organisms is primarily responsible for the degradation of lignin?

• Viruses

• Protozoa

• Fungi

• Bacteria