Question

the nitrogen cycle
concept map 3: decaying organisms
fill in the boxes with the correct words from the list at the bottom of the page.
decaying organisms
free nitrogen
box
which can be or acted on by
box box
by plants, then
box box
nitrogen atoms they contain into which convert some of the
box box
living in their tissues to a
box
which is
box into the atmosphere
use these words:
absorbed gas
bacteria nitrogen
binding protoplasm
denitrifying released
compounds

Explanation:

Step1: Fill first empty box

Decaying organisms release nitrogen compounds as free nitrogen.

Step2: Split into two pathways

Left path: compounds are absorbed by plants.
Right path: compounds are acted on by bacteria.

Step3: Complete left plant pathway

Plants bind nitrogen into protoplasm (living cell material).

Step4: Complete right bacteria pathway

Act on by denitrifying bacteria, which target nitrogen compounds in tissues, convert to gas, then released into atmosphere.

Answer:

Top empty box (after "free nitrogen"): nitrogen compounds
Left branch first box: absorbed
Left branch second box: binding
Left branch third box: protoplasm
Right branch first box: bacteria
Right branch second box: denitrifying
Right branch third box: nitrogen compounds
Right branch fourth box: gas
Right branch fifth box: released