Biogeochemical Cycles Part 2 (Nitrogen & Carbon)

Which nitrogen cycle process is occurring when bacteria convert ammonium to nitrite and then into nitrate?

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

Which nitrogen cycle process is occurring when plant roots absorb ammonium ions and nitrate ions for use in making molecules such as DNA, amino acids, and proteins?

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

Which of these nitrogen molecules would be present in the atmosphere?

• NH₃

• NH₄⁺

• NO₃^-

• N₂

Which of these nitrogen cycle processes converts atmospheric nitrogen to the usable form of nitrogen, called nitrate?

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

Which of these nitrogen cycle processes takes nitrogen from its largest reservoir?

• nitrogen fixation

• nitrification

• denitrification

• ammonification

• assimilation

According to this diagram, plants use nitrogen to make _________________________

• carbohydrates

• cellulose

• proteins

• unsaturated fats

Our atmosphere contains nearly 80% of _________________but it can not be used directly by the majority of living organisms.

• Oxygen

• Nitrogen

• Carbon dioxide

• ozone

The process of conversion of gaseous nitrogen into Ammonia, a form in which it can be used by plants is ________________

• Nitrogen assimilation

• Nitrogen fixation

• nitrogen degradation

________________ can combine atmospheric or dissolved nitrogen with hydrogen to form ammonia.

• Nitrides

• Bacteria in the soil and cyanobacteria in the oceans

• Algae

process by which ammonia is converted into nitrite and then into nitrates is_________

• nutrification

• nitrogen fixation

• nitrification