What is symbiosis?

Symbiosis is a close relationship between two different species of living things, or organisms. Organisms interact with other organisms all the time. Some organisms have very close relationships with other organisms of different species. These relationships are called symbiotic relationships. In these relationships, at least one of the organisms benefits in some way. Let us look at some symbiotic relationships between different organisms.

Fish called remoras have a symbiotic relationship with sharks. (Photo by Albert Kok and used under this creative commons license)

Remoras often attach themselves to sharks. They are carried along wherever the shark swims. Why do you think they do this?

Bees have a symbiotic relationship with flowering plants.

Bees spend a lot of their time visiting flowers. Do the bees benefit from this relationship? Do the flowers benefit?

Mosquitoes have a symbiotic relationship with people.

Mosquitoes often bite people and drink their blood. Do the mosquitoes benefit from this? Do the people they bite benefit in any way?

Types of symbiotic relationships

There are different types of symbiotic relationships. Some types of symbiotic relationships are mutualism, commensalism and parasitism. We will explore each one in a separate lesson.