Which of the following statements about
lichens and their ecological significance is correct?
1. Lichens
are purely autotrophic organisms that do not rely on any other species for
nutrients.
2. The symbiotic relationship in
lichens is mutualistic, where fungi provide protection and water absorption,
while algae or cyanobacteria provide carbohydrates and vitamins.
3. Lichens are secondary
colonizers that only grow after soil has formed and cannot initiate
colonization on bare rocks.
4. Lichens are limited to
temperate regions and cannot survive extreme environmental conditions.
Select the correct
answer using the code given below: