Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

Lichens are formed mutualist
ecological interaction fungi and
algae between fungi and
. In this ecological
, the fungi absorb that
is then by algae (or
), and algae (or
), as autotrophs, produce
material in excess serve as
food the fungi.