1. Parasitism Ishaba Haque IB ESS Y1 08/02/11

2. What is parsitism? • Parasitism is the relationship between organisms of different species where one organism, the parasite, benefits at the expense of another, the host. (http://en.wikipedia.org/wiki/Parasitism)

3. Types of parasites • Ectoparasites: Parasites that live on the surface of the host. • Epiparasites: Parasites that feed on other parasites. • Endoparasites: Parasites that live inside the host. • Intercellular • Intracellular

4. Ecology • Infrapopulation: All the parasites of one species in a single, individual host. • Metapopulation: All the parasites of one species in a host population. • Infracommunity: All the parasites of all species in a single individual host. • Component community: All the parasites of all species in a host population. • Compound community: All the parasites of all species in all host species in an ecosystem.

5. Transmission • Parasites can go from one host to another by: • Producing offspring inside the host • From a vector such as a mosquito or other insects • From food or contaminated water • Host – to – host contact

6. Role in the Ecosystem • Part of the biosphere as a whole • Interfere processes of competition, migration and stability. • High parasite population densities can lead to the hosts death, and eventually a decrease in that species. • If a decrease of species happened, most other species would decrease too because the food chain would break. • Example: Parasite  Deer  Lion 

7. Bibliography • http://www.springerlink.com/content/k2g202631056141x/ • http://answers.yahoo.com/question/index?qid=20090801201648AAWVCpH • http://en.wikipedia.org/wiki/Parasitism#Types_of_parasitism • Environmental System and Societies – Course Companion by Jill Rutherford