Some symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival. For example, many lichens consist of fungal and photosynthetic symbionts that cannot live on their own. Others are facultative (optional): they can, but do not have to live with the other organism. COUNT 3
QSN1 What is the type of symbiotic relationship where two organisms can't survive without each other? ANS1 obligate QSN2 What is the type of symbiotic relationship where the symbionts can live together but can also survive alone? ANS2 facultative QSN3 What is an example of an obligate relationship? ANS3 lichens