35. Soil

How do animals obtain usable nitrogen for their biological processes?

Denitrification is an essential step in which of the following cycles?

In the context of nitrogen fixation, what role do lichens play in helping to create soil during primary succession?

How do plants obtain the nitrogen they need for growth?

How might the nitrogen cycle change if nitrogen-fixing bacteria and archaea went extinct?

How do herbivores obtain the nitrogen they need?

How do most plants obtain the nitrogen they need for growth?

Why is the nitrogen cycle important to humans?

Nitrogen enters the roots of plants in a process called:

Which process is responsible for converting atmospheric nitrogen gas ($N_2$) into biologically usable forms such as nitrite ($NO_2^-$) and nitrate ($NO_3^-$)?

How do animals obtain usable nitrogen for their biological processes?

Where do plants primarily obtain the nitrogen necessary for synthesizing amino acids and DNA?

What is the primary role of decomposers in the nitrogen cycle?

Which process is primarily responsible for returning nitrogen to the atmosphere in the nitrogen cycle?

For what essential biological purpose do plants and animals require nitrogen?