Biology 2483A Lecture Notes - Lecture 13: Ecosystem Engineer, Trematoda, Parasitoid

• School: Western University
• Department: Biology
• Course: Biology 2483A
• Professor: Hugh Henry

Document Summary

Symbionts are organisms that live in or on other organisms and comprise of more than half of earth"s total species. Our own bodies can be a home to many other species. A parasite consumes the tissues or bodily fluids of the organism on which it lives (the host). Pathogens are parasites that cause disease (an abnormal condition affecting the body of an organism). Parasites typically harm, but don"t immediately kill, the organisms they eat (unlike predators). This degree of harm varies widely as witnessed between the fungus that causes athlete"s foot, and yersinia pestis, the bacterium that causes the plague. Parasites typically feed on only one or a few host individuals, which include herbivores such as aphids or nematodes that feed on one or a few host plants. Parasitoids are insects whose larvae feed on a single host and almost always kill it.