Nitrogen cycle Knowledge-Based Download PDF

Questions

1. 1.

   Which process in the nitrogen cycle refers to the uptake of inorganic nitrogen ions by autotrophs and their biochemical incorporation into cellular macromolecules such as proteins and nucleic acids?

   • A) Nitrogen fixation
   • B) Nitrification
   • C) Assimilation
   • D) Ammonification
2. 2.

   Which process in the nitrogen cycle describes the biological breakdown of nitrogen-containing organic compounds found in detritus and metabolic waste into inorganic ammonia or ammonium ions?

   • A) Nitrification
   • B) Denitrification
   • C) Ammonification
   • D) Nitrogen fixation
3. 3.

   Which biological process in the nitrogen cycle is responsible for converting inert atmospheric nitrogen gas ($N_2$) into biologically accessible forms such as ammonia ($NH_3$)?

   • A) Ammonification
   • B) Denitrification
   • C) Assimilation
   • D) Nitrogen fixation
4. 4.

   Which step of the nitrogen cycle is characterized by the sequential biological oxidation of ammonia or ammonium into nitrite, and subsequently into nitrate?

   • A) Ammonification
   • B) Nitrification
   • C) Nitrogen fixation
   • D) Assimilation
5. 5.

   Which biological process in the nitrogen cycle directly converts soil nitrates into gaseous nitrogen, thereby releasing nitrogen back into the atmosphere?

   • A) Nitrogen fixation
   • B) Nitrification
   • C) Denitrification
   • D) Ammonification