Question

Association in a lichen is _______.

• A. Temporary
• B. Parasitic
• C. Permanent
• D. Obligatory

Answer 1

The correct option is D Obligatory

Lichens are formed due to a kind of symbiotic relationship between fungi and cyanobacterium (blue-green algae). The relationship is obligatory in nature they produce their own food by photosynthesis (algal partner helps in this process) but also use the plant or other substance on which they grow as the substrate for other nutrients (fungal partner helps in this process of collection of moisture and nutrients). An obligatory relationship is one in which one or both the partners get benefits.

So, the correct answer is 'obligatory'.