what is Symbiosis ???

s close and often long-term interactions between different biological species In 1877 Bennett used the word symbiosis (which previously had been used of people living together in community) to describe the mutualistic relationship in lichens. In 1879 by the german mycologist  anton de bary, defined it as "the living together of unlike organisms.

ome symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival. For example, many linchens  consist of fungal and photosynthetic symbionts that cannot live on their own.

  Others are facultative, meaning that they can but do not have to live with the other organism.

Symbiotic relationships include those associations in which one organism lives on another ,or where one partner lives inside the other endosymbiosis, such as lactobacilli and other bacteria in humans or zooxanthelles  in corals

  

Mutualism is any relationship between individuals of different species where both individuals derive a benefit. Generally, only lifelong interactions involving close physical and biochemicalbiologists  restrict the definition of symbiosis to close mutualist relationships. contact can properly be considered symbiotic. Mutualistic relationships may be either obligate for both species, obligate for one but facultative for the other, or facultative for both. Many

Commensalism describes a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. It is derived from the English word  commensal used of human social interaction . The word derives from the medieval Latin word, formed from com- and mensa, meaning "sharing a table".mutualism

commensalism

Amensalism

Amensalism is the type of symbiotic relationship that exists where one species is inhibited or completely obliterated and one is unaffected. This type of symbiosis is relatively uncommon in rudimentary reference texts, but is omnipresent in the natural world. An example is a sapling growing under the shadow of a mature tree. The mature tree can begin to rob the sapling of necessary sunlight and, if the mature tree is very large, it can take up rainwater and deplete soil nutrients

amesalism