23.3 Quiz on the Nitrogen Cycle

What happens to a leaf when it lands on the ground and slowly dies?

• It becomes part of the soil immediately.

• Decomposers gather around it and start breaking it down.

• It turns into a new plant.

• It evaporates into the air.

What are proteins in the leaf broken down into?

• Sugars

• Fats

• Amino acids

• Water

What is the process called when ammonium is absorbed by plants?

• Photosynthesis

• Respiration

• Ammonification

• Transpiration

Which bacteria convert nitrate ions into nitrogen gas?

• Nitrosomonas

• Nitrobacter

• Rhizobium

• Lactobacillus

What is the role of nitrosomonas in the nitrogen cycle?

• Convert nitrogen gas into ammonia

• Convert nitrate into nitrogen gas

• Convert ammonium into nitrate

• Convert nitrate into ammonium

How can plants absorb ammonium?

• Through photosynthesis

• By diffusion or active transport

• By osmosis

• Through transpiration

What can nitrate be converted into by nitrobacter?

• Ammonia

• Nitrogen gas

• Nitrate ions

• Oxygen

What completes the nitrogen cycle according to the text?

• Photosynthesis

• Water evaporation

• Leaf senescence and decomposition

• Root growth

What happens to nitrogen gas in the atmosphere during the nitrogen cycle?

• It combines with hydrogen gas

• It turns into oxygen

• It becomes carbon dioxide

• It forms sulfur compounds

What happens to nitrate ions in the soil?

• They are absorbed by plants

• They evaporate into the atmosphere

• They turn into carbon dioxide

• They become sulfur compounds