Symbiosis- living together in direct contact
This means that species that live in direct contact with each other are in a symbiotic relationship. This has different impacts on the organisms involved.
Commensalism is a relationship where one organism benefits and the other (the host) is neither benefited/helped nor harmed. Parasitism is where one organism known as the parasite benefits, and the other is harmed (the host).
Each parasite will have different features that enable them to be successful in their host.
Tapeworms are an example of a parasite. Some are able to cause disease in humans, and are adapted to absorb the digested food inside the intestines of humans. They have a large surface area, meaning that as much digested food/nutrients can diffuse into their bodies. They also have hooks or suckers which allows them to hold onto the walls of the intestines. They can respire anaerobically when there is not enough…