Question

With the help of examples differentiate between facultative symbiosis and obligate symbiosis.

Answer 1

Hint: Symbiosis is the interaction between the two different organisms. It may be mutualistic, parasitic or commensalistic. These lives in close physical association. These are obligatory which means they totally depend upon them for their survival. Here, we are going to see the facultative symbiosis, obligate symbiosis and their differentiation. Through some of the species it could be found and analyzed.

Complete answer:
  Symbiosis may be of the same or different species. The organisms which are present here or exhibit symbiosis are known as the symbionts. Symbiosis may become either facultative or obligate. It depends upon the species. The following is the differentiation between the facultative and the obligate symbiosis. They are as follows:

TOPIC	FACULTATIVE SYMBIOSIS	OBLIGATE SYMBIOSIS
DEFINITION	The parasite that is able to complete its life cycle in the absence of the host is known as the facultative parasite.	The parasite which needs a host to complete its life cycle is known as obligate parasite.
LIFE CYCLE	They have a simple life cycle.	They have a complex life cycle.
PRESENCE OF HOST	They can also survive in the absence of the host.	They can survive in the presence of the host.
FREE-LIVING NATURE	When the host is absent, the parasites are free-living.	These do not have any free-living stages.
TRANSMISSION THROUGH HOST ORGANISMS	These do not travel from one host to another.	These travel from one host to the other.
EXAMPLE	Trentepohlia, FungusExplanation: This can live independently without any host. As we already know that the facultative parasites can live independently, this comes under facultative symbiosis.	Lichens, MycobacteriumExplanation: It consists of both the fungal and photosynthetic symbionts. Here, the fungal partners cannot live on their own. As we already know that obligate parasites cannot live independently, this comes under obligate symbiosis.

Note:
    Symbiotic relationships here are very much an important component in an ocean. They can share habitats or lifestyles in a specific way. These are also important in the function of the natural ecosystems. There is mutual benefit here but there is no obligation on either organism. These are the definitions, explanations of the symbiotic relationship.