Nitrogen Cycle

Front

In what form do plants absorb the majority of nitrogen from the soil? Options: Gaseous Nitrogen, Nitrous Oxide, Nitrogen Dioxide, Nitrites, Nitrates

Back

Nitrates

Front

Why do plants need to absorb nitrogen from the soil?

Back

Plants require nitrogen to synthesize important nitrogen-containing compounds, like proteins.

Front

Why is the nitrogen cycle important for living things?

Back

It helps build proteins (in cells and DNA).

Front

What percentage of Earth’s atmosphere is nitrogen gas (“free” nitrogen)?

Back

78% (or 78 percent)

Front

Can most organisms use “free” nitrogen gas in the atmosphere?

Back

No

Front

Which of the following performs most nitrogen fixation?

• Plants
• Bacteria
• Animals
• Soil

Back

Bacteria

Front

What do decomposers (decomposition) do in the nitrogen cycle?

Back

put nitrogen into soil

Front

Bacteria break down organic matter and return carbon dioxide to the environment. This is an example of: denitrification, decomposition, nitrogen fixation, symbiosis

Back

denitrification

Front

The picture shows root nodules on a pea plant. Those root nodules are colonized by nitrogen-fixing bacteria. What is the nature of the relationship?

Back

Both the bacteria and the pea plant benefit from this relationship.

Front

Which organisms convert nitrates in the soil back into atmospheric nitrogen?

Back

Denitrifying bacteria