Parasitism and Mutualism

Some species live together in symbiotic relationships. There are several types, but two common forms of symbiotic relationships are:

  • Parasitism
  • Mutualism


Parasites live within or on a larger organism, which is called a host. The parasite benefits by taking nutrients from the host, but the host often suffers harm and gets no benefit in return.

In humans, an example of a parasite is the tapeworm, which lives inside the gut. It ‘steals’ nutrients from the host, which can lead to malnutrition.


Mutualism is a type of relationship in which both species involved benefit from their interaction, such as through the exchange of nutrients.

An example of this is the mutualistic relationship between flowers and bees. Bees get nectar from the flowers, which they can use for food. In the process, bees spread the flower pollen to other flowers, which helps with plant reproduction.