What is symbiosis?
Symbiosis is close and often long-term interaction between two or more different biological species.
The definition of symbiosis is controversial among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any types of persistent biological interactions.
The definition of symbiosis is controversial among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any types of persistent biological interactions.
Mutualism
Mutualism is any relationship between individuals of different species where both individuals benefit. In general, only lifelong interactions involving close physical and biochemical 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 biologists restrict the definition of symbiosis to close mutualist relationships.
Example
The lichens in which fungus and algae both benefit each other.
Both organisms benefit from this association as the algal(cyanobacterial partner) possess the green pigment chlorophyll, enabling them to use sunlight’s energy to make their own food from water and carbon dioxide through photosynthesis. They also provide vitamins to the fungi. Cyanobacteria can make amino acids directly from the nitrogen gas in the atmosphere.
The fungi, in turn, protects its partners from drying out and shades them from strong sunlight by enclosing the photosynthesizing partners within the body of the lichen.
Commensalism
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"
Example
Like an opossum who will den with a woodchuck for warmth, without helping or hurting the woodchuck.
Parasitism
A parasitic relationship is one in which one member of the association benefits while the other is harmed. This is also known as antagonistic or antipathetic symbiosis. Parasitic symbioses take many forms, from endoparasites that live within the host's body to ectoparasites that live on its surface. In addition, parasites may be necrotrophic, which is to say they kill their host, or biotrophic, meaning they rely on their host's surviving. Biotrophic parasitism is an extremely successful mode of life. Depending on the definition used, as many as half of all animals have at least one parasitic phase in their life cycles, and it is also frequent in plants and fungi. Moreover, almost all free-living animals are host to one or more parasite taxa. An example of a biotrophic relationship would be a tick feeding on the blood of its host.
Example
Tape worm eating a humans food
Competition
A lot of birds and a squirrel fighting for the same nuts only capable of feeding one species.
They are fighting for food, for the thing that can support their lives. But the food is not enough, so there will be a competition between animals.
Even between plants, they have competitions every day, and fighting for sunlight, water, and etc.
Predation
Bird of prey eats a rodent.
Predation describes a biological interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked). Predators may or may not kill their prey prior to feeding on them, but the act of predation often results in the death of its prey and the eventual absorption of the prey's tissue through consumption.
That is the law of the jungle.
Why is symbiosis important?
It may be used for close associations such as commensalism. Many symbioses are obligatory, the participants cannot survive without the interaction. For example a lichen is an obligatory symbiotic relationship between an alga or a cyanobacterium and a fungus. Without each other they can not survive.
If one organism is no longer present, the organisms that have symbiosis relationship with is will be affected.
If one organism is no longer present, the organisms that have symbiosis relationship with is will be affected.