Symbiosis Explained: Mutualism, Commensalism and Parasitism (Grade 6 to 8 Science)

Hi, I'm Luna from DoodleBeez. In nature, some species live in close relationships with each other. This is called symbiosis. Today we will learn the three main types and how to tell them apart.

There are three main types. In mutualism, both species benefit. In commensalism, one benefits and the other is not affected. In parasitism, one benefits and the other is harmed.

Mutualism is a win for both. Clownfish live among the stinging tentacles of sea anemones, which protect them from predators. In return, clownfish chase away fish that eat anemones and help clean them.

Bees and flowers are another example of mutualism. Bees get nectar for food. While feeding, they carry pollen from flower to flower, helping the plants make seeds.

Commensalism helps one species without affecting the other. Barnacles attach to the skin of whales and ride along to food filled waters. The whale is generally not helped or harmed.

Parasitism helps one species and harms the other. A tick feeds on the blood of a dog. The tick benefits, but the dog loses blood and can catch diseases. The parasite usually does not kill its host quickly.

Now it's your turn. Cattle egrets follow grazing cows and eat the insects the cows stir up. The cows are not affected. What type of symbiosis is this? Pause and try. It is commensalism.

Great job! Remember, symbiosis is a close relationship between species. Mutualism helps both, commensalism helps one without affecting the other, and parasitism helps one and harms the other. Practice symbiosis in the Science Lab at doodlebeez.com. See you next time!