Question

will symbiosis be feasible for lichens in absence of fungus

Answer 1

nope as lichens means the symbiotic relationship of algae with fungi
if one of them is absent then it will not called as lichens

Answer 2

Answer:

Symbiosis will not be feasible for lichens in the ‘absence of funguses’.  

Explanation:

Lichens are a symbiotic establishment between ‘algae and fungi’ where both the partners mutually benefit from each other. The fungi provide support, attachment and an anchor for the lichens.  

The lichen is protected from the environment by the fungal filaments, within the networks of which are embedded the algae. These filaments also gather nutrients and moisture for the lichens from the environment to synthesize food.