Final answer:
Symbiosis is a close, often long-term biological interaction between two different species where at least one benefits. It can manifest as mutualism, commensalism, or parasitism. These interactions play a crucial role in the ecology and evolution of the species involved.
Step-by-step explanation:
Definition of Symbiosis
Symbiosis is characterized as a close and often long-term interaction between two different species. In these relationships, at least one of the organisms benefits significantly.
There are three primary types of symbiotic relationships: mutualism, commensalism, and parasitism. Mutualism is a form of symbiosis where both species benefit from the relationship.
An example of this could be bees pollinating flowers while obtaining nectar. Commensalism involves one species benefiting while the other is neither helped nor harmed, such as barnacles attaching to a whale. The whale does not benefit from carrying the barnacles, but it is not harmed by them either. Parasitism is the type of symbiosis where one organism, the parasite, benefits at the expense of the other, the host, which is harmed by the relationship, like a tick feeding on a deer.
Symbiotic relationships are essential to the ecology and evolution of interacting species. They can affect the distribution and abundance of the participating organisms and can be complex, often involving more than just two species. While symbiosis can involve obligatory interactions necessary for at least one organism's survival, there are also non-obligatory, transient relationships.