The symbiotic association between an alga and a fungus is known as:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Lichen
A lichen is a partnership of an alga and a fungus living together. The alga has chlorophyll and makes food for both; the fungus gives shelter, water and minerals.
Why the other options are incorrect
Option (1) Commensalism — Incorrect. A relationship in which one partner gains and the other is neither helped nor harmed.
Option (2) Mycorrhiza — Incorrect. A partnership of a fungus with the roots of a higher plant, not with an alga.
Option (4) Saprotroph — Incorrect. An organism that feeds on dead and decaying matter, such as many fungi.