Use each of the terms below only once to complete the passage.
ammonia
denitrification
atmosphere
nitrogen fixation
consumers
plants
decay
proteins
Nitrogen is a nutrient that organisms need to produce (12).
Plants and animals cannot use the nitrogen that makes up a large percentage of the
(13)
by plants in a process called (14).
(15)
decomposers
urinate
The nitrogen is captured and converted into a form that is usable
Nitrogen enters the food web when
absorb nitrogen compounds from the soil and use them to make
get nitrogen by eating plants or animals that contain
proteins. (16).
nitrogen. Nitrogen is returned to the soil when animals (17)_
organisms die and (18)_
or when
break
(19)
This compound is
down organic matter found in organisms into (20).
changed by organisms in the soil into other nitrogen compounds that can be used by plants. Finally, some
soil bacteria convert nitrogen compounds into nitrogen gas, which returns to the atmosphere in a process
called (21).