Parasitism & Mutualism (Edexcel GCSE Combined Science): Revision Note

Exam code: 1SC0

Alistair Marjot

Last updated

Parasitism & Mutualism

  • The survival of some organisms in a community is dependent on other species within the same community

    • This is known as interdependence

  • Two examples of interactions that can create interdependence within a community include:

    • Parasitism (parasitic relationships)

    • Mutualism (mutualistic relationships)

Parasitic relationships

  • Parasites are organisms that are adapted to live very closely with another species, known as the host (or the host species)

    • The parasite lives either in or on the body of the host species

  • The parasite gains resources (i.e. what it needs in order to survive) from the host

    • This can include, food, shelter and a suitable location to reproduce (where offspring can feed and grow)

  • However, the host doesn't get any benefits from this relationship

    • In fact, parasites often harm the host in some way

  • An example of a parasitic relationship is fleas being a parasite to mammals (e.g. dogs)

    • The fleas feed on the host's blood but don't provide anything to the host in return

Mutualistic relationships

  • A mutualism is a type of relationship between two species within a community, where both organisms benefit in some way

  • For example, bees and many species of flowering plants have a mutualistic relationship

    • Bees gain nectar (i.e. food to provide them with energy) from flowers

    • When bees visit flowers, pollen is transferred to their bodies

    • As bees visit multiple different flowers, they spread the pollen to these flowers, pollinating them

    • In this way, the flowers gain help in reproducing

👀 You've read 1 of your 5 free revision notes this week
An illustration of students holding their exam resultsUnlock more revision notes. It's free!

By signing up you agree to our Terms and Privacy Policy.

Already have an account? Log in

Did this page help you?

Alistair Marjot

Author: Alistair Marjot

Expertise: Environmental Systems and Societies & Biology Content Creator

Alistair graduated from Oxford University with a degree in Biological Sciences. He has taught GCSE/IGCSE Biology, as well as Biology and Environmental Systems & Societies for the International Baccalaureate Diploma Programme. While teaching in Oxford, Alistair completed his MA Education as Head of Department for Environmental Systems & Societies. Alistair has continued to pursue his interests in ecology and environmental science, recently gaining an MSc in Wildlife Biology & Conservation with Edinburgh Napier University.

Download notes on Parasitism & Mutualism