CK12 Life Science

(Marvins-Underground-K-12) #1

Parasites include those that either live within the host’s body, such as hookworms, or those
that live on its surface, such as lice. In addition, parasites may either kill the host they live
on, or rely on the host surviving. Parasites are found not only in animals but also in plants
and fungi.


Figure 23.15: A mutualistic relationship between the Ocellaris clownfish and the Ritteri sea
anemone. Myako Island, Japan. The fish protects the anemone from anemone-eating fish
and the anemone protects the clownfish from its predators, with its stinging tentacles. The
clownfish has a special mucus which protects it from the tentacles. ( 22 )


Lesson Summary



  • A community is an assemblage within the same area, of populations of different species
    interacting with one another.

  • Community interactions include competition, predation, and symbiosis.

  • Competition can be either direct or indirect.

  • Intra- and inter-specific competition occur when individuals share a limiting resource
    in the same area.

  • The competitive exclusion principle plays an important role in natural selection.

  • Functional types of predation include true predation, grazing, and parasitism.

  • Predators can also be classified by degree of specialization.

  • Prey use different adaptations to avoid detection, attack and capture by predators.

  • Symbiosis includes mutualism, commensalism, and parasitism.

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