The Nitrogen Cycle Flashcards

All 7 cards in this deck

What do nitrogen-fixing bacteria do?

They convert nitrogen gas from the air into nitrogen compounds (ammonia/nitrates); they live in soil and in root nodules of legumes such as peas and beans.

What do nitrifying bacteria do?

They convert ammonia in the soil into nitrites and then into nitrates.

True or false? Denitrifying bacteria convert nitrates in the soil into nitrogen gas.

True. This removes nitrates from the soil and returns nitrogen to the atmosphere.

What do decomposing bacteria convert urea and proteins in dead matter into?

Ammonia.

What two farming methods increase the nitrates available to crops?

Adding fertiliser (manure or artificial nitrate fertiliser), and crop rotation with legumes, whose root nodules contain nitrogen-fixing bacteria.

What do plants use the nitrates they absorb from the soil for?

To make amino acids, which are joined to form proteins.

True or false? A plant growing in soil that is low in nitrates will show stunted growth.

True. Without enough nitrates the plant cannot make enough protein for growth.