Sept 21 Water Nitrogen Carbon Cycles

What process converts nitrogen gas into a biologically useful (fixed) form?

• Respiration

• Assimilation

• Denitrification

• Nitrogen fixation

Which organisms play the largest role in converting nitrogen into various usable forms and back to a gas form?

• rabbits

• bacteria

• plants

• worms

How do animals get nitrogen to make important biological molecules?

• Breathe it in through the air

• Fix it from nitrogen gas

• Consume other organisms

• Assimilate it through the soil

What happens to carbon during the process of photosynthesis?

• CO₂ is released by plants

• CO₂ is taken up by plants

• organic carbon is taken up through plant roots

• carbon is lost through heat

What happens to carbon during the process of photosynthesis?

• CO₂ is released by plants

• CO₂ is taken up by plants

• organic carbon is taken up through plant roots

• carbon is lost through heat

The process of breathing in oxygen and releasing carbon dioxide into the air (or water) is...

• Assimilation

• Decomposition

• Photosynthesis

• Respiration

Which gas is most abundant in the atmosphere?

• carbon dioxide

• methane

• nitrous oxide

• nitrogen gas

Which of the following does NOT release carbon dioxide into the atmosphere?

• volcanic activity

• respiration

• photosynthesis

• fossil fuel combustion

The process of making nitrites and nitrates is...

• denitrification

• nitrogen fixation

• nitrification

• ammonification

What does denitrification do?

• converts fixed nitrogen into nitrogen gas

• converts nitrogen gas into fixed nitrogen

• makes nitrates

• makes ammonia